• TABLE OF CONTENTS
HIDE
 Index
 Main
 Introduction
 Applied genetics
 Coping with calving difficulti...
 Factors affecting calf crop...
 Selection and culling of femal...
 A controlled, seasonal cattle breeding...
 Determining pregnancy in cattl...
 Crossbreeding of beef cattle
 Heat detection and artificial insemination...
 Florida production testing program...
 Farm and ranch post-weaning performance...
 Main
 Daily nutrient requirements of...
 Balancing rations for beef...
 Water for beef cattle
 Vitamins for the beef herd
 Minerals for beef cattle
 Beef: individual identification...
 Management of the beef cow at calving...
 Management of the beef cow at calving...
 Castration and dehorning
 Creep-feeding nursing beef...
 Grouping the commercial beef herd...
 Early weaning of beef calves
 Credit for beef cattle operati...
 Cow herd taxes
 Cow herd budget
 Grazing systems
 Hay feeding systems
 Small grain pastures
 Quality hay production
 Forage testing
 Beef cow-calf health handbook
 Table of Contents
 Planned herd health management
 Vaccination programs
 Common infectious diseases
 Parasite control
 Nutrition management in disease...
 Poison prevention
 Breeding management and reproductive...
 Preconditioning feeder calves
 Other management to support herd...
 Foot rot in beef cattle
 Tuberculosis
 Pinkeye
 Respiratory infections in beef...
 Blackleg and clostridial disea...
 Chemical and drug residues
 Administration of medicine and...
 Diseases of reproduction
 Anaplasmosis
 Poisonous plants
 Hay storage for a cow-calf...
 Gates and passageways
 Electric fences
 Wire fences
 Shrink and its importance to cowmen...
 Organization of feeder cattle...
 The use of futures market for hedging...
 Marketing alternatives for feeder...






Title: Florida beef production guide composed of the Southern regional beef cow-calf handbook plus other IFAS publications
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00095014/00001
 Material Information
Title: Florida beef production guide composed of the Southern regional beef cow-calf handbook plus other IFAS publications
Alternate Title: Beef production handbook
Southern regional beef cow-calf handbook
Physical Description: 1 v. (various paging, loose-leaf) : ill. ; 30 cm.
Language: English
Creator: University of Florida -- Institute of Food and Agricultural Sciences
Donor: unknown ( endowment ) ( endowment )
Publisher: Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainseville, Fla.
Publication Date: 1980
Copyright Date: 1980
 Subjects
Subject: Beef cattle -- Handbooks, manuals, etc -- Florida   ( lcsh )
Genre: handbook   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
General Note: Caption title.
General Note: "1/80."
Statement of Responsibility: Institute of Food and Agricultural Sciences, University of Florida.
 Record Information
Bibliographic ID: UF00095014
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 436870034

Table of Contents
    Index
        Page i
        Page ii
    Main
        Page iii
    Introduction
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
    Applied genetics
        Page 1001.1
        Page 1001.2
        Page 1001.3
        Page 1001.4
    Coping with calving difficulties
        Page 1002.1
        Page 1002.2
        Page 1002.3
        Page 1002.4
        Page 1002.5
    Factors affecting calf crop percentage
        Page 1003.1
        Page 1003.2
        Page 1003.3
        Page 1003.4
        Page 1003.5
    Selection and culling of females
        Page 1004.1
        Page 1004.2
        Page 1004.3
    A controlled, seasonal cattle breeding program
        Page 1005.1
        Page 1005.2
        Page 1005.3
        Page 1005.4
    Determining pregnancy in cattle
        Page 1006.1
        Page 1006.2
        Page 1006.3
        Page 1006.4
        Page 1006.5
        Page 1006.6
        Page 1006.7
        Page 1006.8
        Page 1006.9
        Page 1006.10
    Crossbreeding of beef cattle
        Page 1007.1
        Page 1007.2
        Page 1007.3
        Page 1007.4
        Page 1007.5
    Heat detection and artificial insemination in cattle
        Page AS 4
        Page AS 4a
    Florida production testing program for beef cattle
        Page AS 5
        Page AS 5a
        Page AS 5b
        Page AS 5
        Page AS 5d
        Page AS 5e
        Page AS 5f
        Page AS 5g
    Farm and ranch post-weaning performance testing
        AS Report - 1
        AS Report - 1a
        AS Report - 1b
        AS Report - 1c
    Main
        AS Report - 1d
    Daily nutrient requirements of beef cattle
        Page 2000.1
        Page 2000.2
        Page 2000.3
        Page 2000.4
        Page 2000.5
        Page 2000.6
        Page 2000.7
        Page 2000.8
        Page 2000.9
        Page 2000.10
        Page 2000.11
    Balancing rations for beef cattle
        Page 2001.1
        Page 2001.2
        Page 2001.3
        Page 2001.4
        Page 2001.5
        Page 2001.6
        Page 2001.7
    Water for beef cattle
        Page 2002.1
        Page 2002.2
        Page 2002.3
        Page 2002.4
    Vitamins for the beef herd
        Page 2003.1
        Page 2003.2
        Page 2003.3
    Minerals for beef cattle
        Page 2004.1
        Page 2004.2
        Page 2004.3
        Page 2004.4
        Page 2004.5
        Page 2004.6
    Beef: individual identification of cattle
        Page 3000.1
        Page 3000.2
        Page 3000.3
        Page 3000.4
    Management of the beef cow at calving time (prior, during and after)
        Page 3001.2
        Page 3001.3
    Management of the beef cow at calving time (prior, during and after)
        Page 3002.1
        Page 3002.2
        Page 3002.3
        Page 3002.4
    Castration and dehorning
        Page 3004.1
        Page 3004.2
        Page 3004.3
    Creep-feeding nursing beef calves
        Page 3005.1
        Page 3005.2
        Page 3005.3
        Page 3005.4
    Grouping the commercial beef herd for winter feeding
        Page 3006.1
        Page 3006.2
        Page 3006.3
        Page 3006.4
    Early weaning of beef calves
        Page 3007.1
        Page 3007.2
        Page 3007.3
        Page 3007.4
    Credit for beef cattle operations
        Page 4000.1
        Page 4000.2
        Page 4000.3
        Page 4000.4
    Cow herd taxes
        Page 4001.1
        Page 4001.2
        Page 4001.3
        Page 4001.4
    Cow herd budget
        Page 4002.1
        Page 4002.2
        Page 4002.3
        Page 4003.1
        Page 4003.2
        Page 4003.3
    Grazing systems
        Page 5000.1
        Page 5000.2
        Page 5000.3
        Page 5000.4
        Page 5001.1
        Page 5001.2
        Page 5001.3
        Page 5001.4
        Page 5001.5
        Page 5001.6
        Page 5001.7
    Hay feeding systems
        Page 5002.1
        Page 5002.2
        Page 5002.3
        Page 5002.4
    Small grain pastures
        Page 5003.1
        Page 5003.2
        Page 5003.3
        Page 5003.4
        Page 5003.5
    Quality hay production
        Page 5004.1
        Page 5004.2
        Page 5004.3
        Page 5004.4
    Forage testing
        Page 5005.1
        Page 5005.2
        Page 5005.3
    Beef cow-calf health handbook
        Page i
    Table of Contents
        Page ii
        Page iii
    Planned herd health management
        Page 1
        Page 2
    Vaccination programs
        Page 3
        Page 4
        Page 5
        Page 6
    Common infectious diseases
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
    Parasite control
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
        Page 40
        Page 41
    Nutrition management in disease prevention
        Page 42
        Page 43
        Page 44
        Page 45
        Page 46
        Page 47
        Page 48
        Page 49
    Poison prevention
        Page 50
        Page 51
        Page 52
        Page 53
        Page 54
        Page 55
        Page 56
        Page 57
        Page 58
        Page 59
        Page 60
        Page 61
    Breeding management and reproductive diseases
        Page 62
        Page 63
        Page 64
        Page 65
        Page 66
        Page 67
        Page 68
        Page 69
        Page 70
    Preconditioning feeder calves
        Page 71
        Page 72
        Page 73
    Other management to support herd health
        Page 74
        Page 75
        Page 76
        Page 77
        ENT-29 i
        ENT-29 ii
        ENT-29 iii
        ENT-29 iv
        ENT-29 v
        ENT-29 vi
        ENT-29 vii
        ENT-29 viii
        EC-426 1
        EC-426 3
        EC-426 4
        EC-426 5
        EC-426 6
        EC-426 7
        EC-426 8
        EC-426 9
        EC-426 10
        EC-426 11
        EC-426 12
        EC-426 13
        EC-426 14
        EC-426 15
        EC-426 16
        EC-426 17
        EC-426 18
        EC-426 19
        EC-426 21
    Foot rot in beef cattle
        Page 6000.1
        Page 6000.2
    Tuberculosis
        Page 6001.1
        Page 6001.2
    Pinkeye
        Page 6002.1
        Page 6002.2
        Page 6002.3
    Respiratory infections in beef cattle
        Page 6003.1
        Page 6003.2
        Page 6003.3
    Blackleg and clostridial diseases
        Page 6004.1
        Page 6004.2
        Page 6004.3
    Chemical and drug residues
        Page 6005.1
        Page 6005.2
        Page 6005.3
    Administration of medicine and vaccine to cattle
        Page 6007.1
        Page 6007.2
        Page 6007.3
        Page 6007.4
        Page 6007.5
    Diseases of reproduction
        Page 6008.1
        Page 6008.2
        Page 6008.3
    Anaplasmosis
        Page 6010.1
        Page 6010.2
    Poisonous plants
        Page 6011.1
        Page 6011.2
        Page 6011.3
        Page 6011.4
        Page 6011.5
    Hay storage for a cow-calf operation
        Page 7000.1
        Page 7000.2
    Gates and passageways
        Page 7001.1
        Page 7001.2
    Electric fences
        Page 7002.1
        Page 7002.2
        Page 7002.3
    Wire fences
        Page 7004.1
        Page 7004.2
        Page 7004.3
        Page 7004.4
        Page 7004.5
        Page 7004.6
    Shrink and its importance to cowmen and cattle feeders
        Page 8000.1
        Page 8000.2
    Organization of feeder cattle sales
        Page 8001.1
        Page 8001.2
    The use of futures market for hedging beef cattle
        Page 8002.1
        Page 8002.2
        Page 8002.3
        Page 8002.4
        Page 8002.5
        Page 8002.6
        Page 8002.7
    Marketing alternatives for feeder calf producers
        Page 8003.1
        Page 8003.2
        Page 8003.3
        Page 8003.4
        Page 8003.5
        Page 8003.6
Full Text


INDEX


Florida Beef Production Guide Composed of the Southern Regional Beef Cow-Calf
Handbook Plus other IFAS Publications.


INTRODUCTION SR

SR 1000
SR 1001
SR 1002
SR 1003
SR 1004
SR 1005
SR 1006
SR 1007
AS-4

AS-5

AS Report 1


2000
2000
2001
2002
2003
2004


SR 3000
SR 3000
SR 3001

SR 3002


3004
3005
3006


SR 3007


4000
4000
4001
4002
4003

5000
5000
5001
5002
5003
5004
5005


Beef Cows as Community Assets

BREEDING, SELECTION, AND REPRODUCTION SECTION
Applied Genetics
Coping with Calving Difficulties
Factors Affecting Calf Crop Percentage
Selection and Culling of Females
A Controlled, Seasonal Cattle Breeding Program
Determining Pregnancy in Beef Cattle
Crossbreeding of Beef Cattle
Heat Detection and Artificial Insemination in
Cattle
Florida Production Testing Program for Beef
Cattle
Farm and Ranch Post-Weaning Performance Testing


NUTRITION SECTION
Daily Nutrient Requirements of Beef Cattle
Balancing Rations for Beef Cattle
Water for Beef Cattle
,Vitamins for the Beef Herd
Minerals for the Beef Cattle

PRODUCTION MANAGEMENT SECTION
Beef: Individual Identification of Cattle
Management of the Beef Cow at Calving Time
(Prior, During, and After)
Management of the Commercial Cow-Calf Herd
for High Calf Crop Percentage
Castration and Dehorning
Creep-Feeding Nursing Beef Calves
Grouping the Commercial Beef Herd for Winter
Feeding
Early Weaning of Beef Calves

BUSINESS MANAGEMENT SECTION
Credit for Beef Cattle Operations
Cow Herd Taxes
Cow Herd Budget
The Cost of Credit

FORAGES SECTION
Grazing Systems
Forage Related Cattle Disorders
Hay Feeding Systems
Small Grain Pastures
Quality Hay Production
Forage Testing


1/80








INDEX
Page 2


SR 6000
VS
ENT-29
EC-426
SR 6000
SR 6001
SR 6002
SR 6003.
'SR 6004
SR 6005
SR 6007.

SR- 6008
SR 60101 '
SR 6011


- V


HERD HEALTIHSECTION
Beef Cow-Calf Health Handbook
Biology of External Parasites on Cattle
SControl of Pests on Beef Cattle
Foot Rot in Beef Cattle
S Tuberculosis
Pinkeye
Respiratory Infections in Beef Cattle
: Blackleg and Clostridial Diseases
Chemical and Dry Residues
Administration of Medicine and Vaccine to
Cattle
S .Diseases of Reproduction
Anaplasmosis
.Poisonous Plants

EQUIPMENT AND FACILITIES SECTION
Hay Storage for a Cow-Calf Operation
Gates and Passageways
Electric Fences
Wire Fence

MARKETING SECTION '
Shrink aid Its Importance to Cowmen and
.Cattle Feeders
t Organization of Feeder Cattle Sales
.The Use of Future Market for Hedging
Beef Cattle
Marketing Alternatives for Feeder Calf
Producers


7000
7000
7001
7002
7004


SR 8000
SR 8000

- SR 8001
, SR 8002

SR 8003


-'4*'.-


TM '"'F~-;i~



Avip


44


~




1









SOUTHERN REGIONAL


COW-CALF HANDBOOK


distributedby the Institute of Food and Agricultural Sciences/University of Florida
Beef Cows As Community Assets

James T. Hall, Economist, Management, ES-USDA


While the importance of agricultural enterprises to
the economy of rural areas is widely recognized and ac-
knowledged, efforts on a community basis to improve
income from these sources is often not undertaken. Rural
communities sometimes do not look upon beef cows and
other agricultural enterprises as being assets to the com-
munity economic base which may be developed to im-
prove the income of their rural area. On the other hand,
much effort, time, and money is often expended in rural
communities on the attraction of outside industries to
locate in the community.
These outside industries, while utilizing local labor
and perhaps other community facilities, may not have the
impact on improving community income that can be
realized by development of beef cows or other agricul-
^^ tural enterprises if the land resource is underutilized.
Income multipliers are frequently used to indicate
the effect of increased income from various sectors of the
economy to the overall income of the community. These
income multipliers indicate the amount of household
income generated throughout the economy with each
additional $1 increase in income in a particular sector.
Income multipliers for cattle and other types of livestock
are among the highest for any economic sector or enter-
prise. Income multipliers will vary considerably depend-
ing upon the economic area under study and the inter-
relationships among sectors. A study entitled "The
Structure of the Alabama Economy: An Input-Output
Analysis" produced in 1972 by Auburn University,
indicated that the income multiplier for all livestock was
2.39. This multiplier was exceeded only by three other
sectors in the Alabama economy; these included agricul-
tural processing 3.26; lumber and wood pro-
ducts 2.54; and furniture and fixtures 2.78. The in-
come multiplier for all sectors of the Alabama economy
was estimated to be 2.14.
A similar study by the State of Kansas entitled: "The
Inter-Industry Structure of the Kansas Economy," pub-
lished in 1969, indicated that cattle had the highest
income multiplier of any agricultural product in that
state. This was exceeded only by crude oil and natural gas,
meat products, and grain mill products. Among agricul-
tural products, the Kansas study indicated that cattle had
an income multiplier of 5.0, poultry products 1.8, corn
1.7, and wheat 1.8.


While income multipliers are often used to demon-
strate the effect of a new industry or other source of
income being introduced into a community, it should be
recognized that a portion of the income so generated will
likely be spent outside of the community thus its affect
is somewhat diluted. For example, all of an industrial
payroll is not spent in the local area, because some
persons live outside the local area and commute to work,
and also some workers who live in the community buy
goods and services elsewhere. In addition, state, federal,
and local taxes reduce spendable income. The same is
true, but, probably to a lesser degree, with increased
income from agricultural enterprises such as cattle herds.
One reason for this, of course, is that there does not tend
to be many commuters among beef herd operators. Al-
though they may commute to and from town to another
job, they tend to reside in the community where their live-
stock is located.
Another reason for the high income multiplier
associated with livestock and cattle enterprises, is un-
doubtedly the fact that most of the resources necessary for
obtaining the output are available in the local area,
whereas a manufacturing plant or similar facility may im-
port large amounts of raw materials into the plant, fabri-
cate it, and ship it out again. These plants utilize local
labor, community facilities, etc., but, little in the way of
natural resources. The same rationale for.high income
multipliers would apply to agricultural processing,
mining, forestry, and oil and natural gas.
One limitation of cattle as a community income
development device is the fact that the beef cow enter-
prise has a low labor requirement. For example, a full
time man or equivalent can, if properly equipped, care for
two to three hundred beef cows. Thus, the addition of
10,000 additional beef cows into an economic develop-
ment area might provide additional direct employment
for only 35-50 workers or owners. Gross sales from 10,000
cows with offspring sold as yearlings would be $2-3
million depending upon product prices. A small
industrial plant with a comparable gross sales figure
might employ several times as many people. For ex-
ample, in the Alabama study, mentioned above, the in-
crease in direct employment due to the addition of a
manufacturing industry with $3.0 million yearly sales was
estimated at 112 persons.







If an income multiplier of 5 is used for cattle, an addi-
tional 10,000 head of cows could increase income
generated throughout the community by approximately
$10 to $15 million per year. An industrial plant with a
multiplier of 2.0-2.5 and sales of $3.0 million per year
would generate $6.0-$7.5 million per year in income.
The effects of increased income to the local commu-
nity, or communities, from beef cattle can also be realized
not only through increased numbers, but also by in-
creased productivity through better breeding, nutrition,
and management, which will increase the pounds of beef
marketed per cow. Additional cows can be added in the
local area in many cases without clearing additional acres
through improved utilization of pastures and ranges. It is
possible to add 25-50 percent additional cow units (cow
and calf or yearling), or more, through improved pasture
management. This has been demonstrated in many areas
in the Southeast. Where many rachers are now utilizing 2-
4 acres per cow unit, it has been demonstrated that, at
least in some areas, it is possible to maintain a cow unit
year round on an acre or two acres. Methods for achiev-
ing the increased rates of production on the same basic
land resource are covered in some detail in other sections
of this handbook.
An organized effort by a community or several com-
munities in the same geographic area to develop beef
cattle production may provide several advantages in-
cluding:
Better utilization of unused or underutilized
resources. This may include land, labor, and capital
of which land is probably the most important. There
are many areas in the South where the land is
probably suitable only for pasture or timber pro-
duction. Determining the number of acres avail-
able and the probable best use of these acres should
be one of the first steps in any developmental pro-
gram. The highest value use of the land from both
an economic and esthetic standpoint will need to be
carefully considered.
The additional income generated by increased cattle
production will accrue not only to those owning the
cattle, but also to the community as was discussed
above.
Additional cattle will provide new jobs not only
on the cattle farms, but in the firms serving these
farms.
Possible development of new businesses may result
from increased cattle production, such as a custom
slaughter plant for locker beef, additional market-
ing firms, etc. If volume is sufficient for a custom
slaughter plant, this should allow people in the com-
munity to purchase beef more economically.


Development of cattle or other agriculture enter-
prises may make the community more attractive to
other types of industry or other businesses. A
vigorous agricultural economy not only provides'
the economic base for most rual communities, but
also can provide an aura of progressive leadership
which is often considered by businessmen seeking a
location for industry. Also the underpininnings pro-
vided by a strong agriculture are likely to result in
adequate community facilities, public services, and
cultural and recreational facilities, which are
important considerations by those seeking new
business locations.
Cattle compete less for available labor in a com-
munity than some other agricultural enterprises.
This, too, may be a consideration important to
those wishing to locate other industries or
companies in a rural area.
Finally, it should be noted that the development of
cattle as a community asset should not be undertaken out
of context with overall development of community re-
sources for both agricultural purposes and plans for
future industrial development. The most profitable and
best use of community resources should be carefully
evaluated including the highest and best use (most profit-
able use) of the land resource, and the esthetic and
cultural values which are deemed important by residents
of the community. Cattle, as community assets and jos-
sible factors in improving the economic situation in a
community, should not be considered to the exclusion of
other possibilities, nor should they be ignored as a
possible important factor in the growth and development
of most non-metropolitan areas in the south.
In his book on effective community industrial
development programs entitled "Bringing in the
Sheaves,"John R. Fernstrom makes the following point.
"Increased emphasis should be placed on developmental
policies that exploit inter-relationships between the
industrial and agricultural sectors so as to .promote
mutual and simultaneous development. There is not a
"best" blend of agricultural developmentand industry for
all areas. The relevant emphasis given to each should vary
according to resources available, and the ultimate
potential for development of a particular area."
REFERENCES
1. Curtis, Wayne C.. "The Structure of the Alabama Eionom 4n
Input-Output Analysis." Auburn University. Agricultural Experi-
ment Station Bulletin 429. February 1972.
2. Emerson. M. Jarvin, et al, "The Interindustry Strui ture vi tihe
Kansas Economy." Kansas Department of Economic De\ elopment.
Manhattan. Kansas. January 1969.
3. Fernstrom. John R., "Bringing in the Sheaves." handbook ior
effective community development programs. Extension Sernice.
U.S. Department of Agriculture. Washington. D. C.. June 1973


COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Act of May 8 and June 30,1914)
Cooperative Extension Service, IFAS, University of Florida
and United States Department of Agriculture, Cooperating
K. R. Tefertiller. Director











(1'~


o -CLE M



30 zC


~9 ~-


FLORIDA COOPERATIVE EXTENSION SERVICE
INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES
UNIVERSITY OF FLORIDA, GAINESVILLE, FLORIDA
John T. Woeste, Dean for Extension


po"' -r


Ilrntmm~rrlrr.lrlmnrrg







A TOTAL CATTLE MANAGEMENT PLAN'


Most cattlemen have a limited amount of resources
available which they can utilize to provide a
continuous base for production and provide their
livelihood. To successfully accomplish this objective
and stay in business, they must make efficient use of
the resources that are at their disposal. All decisions by
the manager must be made in light of their effect on the
total operation, not just a particular phase.
In order to make these decisions intelligently, the
manager must have good records, both production and
financial, and a set of goals for the operation. He also
needs a land use plan to make most efficient use of the
soil resource available to him, a budget to balance
capital availability and need, and some evaluation of
the labor supply. The manager can study these
materials and determine what factors are limiting the
productivity of the operation, then develop long range
goals and a plan for attaining them.
In developing long range goals, the present type and
level of production must be considered as well as
current trends in the market place. The goals and plans
should have flexibility so they can be modified as the
situation changes but provide solid guidance for the
directions the program should be taking. Care must be
exercised to not get carried away by fads or non-
functional trends. Every effort should be made to
capitalize on those strong points of the operation and
improve the weaknesses.
There are several fundamental phases of a beef
operation that must be well done to be successful over
an extended period.
1. Adequate nutrition throughout the year is a must if
acceptable production levels are to be maintained
and any improvement realized. The economics of
this program are important where limited resources
are available.
One area of nutrition frequently overlooked is
mineral supplementation. Read the tag and make
your purchase based on content, not price. The
mineral should contain 25-75% salt, at least 8%
phosphorus and a calcium to phosphorus ratio no
more than 3 parts calcium to 1 part phosphorus and
the closer to 1:1 the better.
Make maximum use of home grown or locally
produced feedstuffs and by-products to reduce the
transportation increment of feed cost. Use high
quality feedstuffs to reduce digestive problems and
stress.
2. Develop and maintain good working facilities. They
reduce stress on the cattle and the cowboys. Also
good facilities encourage the prompt treatment of
problems when the chances for quick and
uneventful recovery are best rather than putting off
treatment until it becomes a major crisis. Make use
of labor saving devices such as lanes and traps to
reduce labor requirements in moving and gathering
your herd.
3. Develop a marketing plan by studying potential
markets available and determine the characteristic
of the most profitable product you can produce.
Analyze your cow herd for its strengths and
weaknesses. Determine what genetic materials
(bulls) are available that will improve on the
weaknesses without hurting the strengths.


Most of the time this will result in a planned
crossbreeding program. Crossbreeding produces
10-15% extra production from heterosis or "Hybrid
vigor". Sire breeds are selected for specific traits
and individuals based on their own merit.
4. Select or purchase superior sires from within the
breed you choose for use in the herd. Base your
selection on the following factors: (1) The
acceptability of their dams' reproductive history, (2)
their own performance, (3) their physical
soundness and structional correctness, and (4)
satisfactory score on a breeding soundness exam
by a qualified veterinarian. Use an adequate
number of bulls (1 per 20-30 cows depending on
age and type of pasture). Remember that most
genetic improvement in the herd will come through
sire selection and today's bulls provide half of the
genetic composition of your cow herd 5 to 10 years
from now.
5. Maintain a short definite breeding season. This will
make for more efficient utilization of labor and
provide a more uniform set of calves at weaning. It
Is important to provide, adequate nutrition to the
herd during this period and then cull those that fail
to breed. Generally the most economical and
effective way to provide adequate nutrition during
the breeding season is to synchronize your
breeding season with your pasture program to
provide an abundance of high quality forage when
you want to breed cows.

6. Develop a program for growing replacement heifers
and give them extra care with their first calves. Try
to keep more heifers than you actually need so that
poor performers can be culled. Particularly effective
is a program to cull based on the first calf they
produce.
7. Do not hesitate to cull open and poor producing
cows. Most ranches are over-stocked for certain
periods of the year and the extra feed made
available will enable the remaining cows to be more
productive. Some form of identification such as
firebrand, eartags, etc. aids in positive identification
of problem animals. Cull for loss of teeth, bad
udders, problem eyes, or anything that could limit
their ability to be productive.
8. Develop in consultation with your local veterinarian
a herd health plan appropriate for your herd and
follow it very carefully: All heifers should b
calfhood vaccinated for Brucellosis because of the
high level of protection this practice affords against
this disease and its high incidence rate in Florida
9. Make use of growth stimulants such as RALGRO2 t
increase the number of pounds you have to sell
The main precaution is to be sure to read the label,
allow the required withdrawal time and observe an
restrictions listed. In several demonstrations around
Florida (table 1) RALGRO implants have produced
an extra 15 to 25 Ibs in 100 days in suckling calves
and 35 to 45 Ibs when implanted twice at 90-12(
days intervals. Yearling steers (table 2) on pasture
had a 15% improvement in gain (25 Ibs). Steers in a
feedlot on a high silage diet implanted twice at 90
day intervals out-gained controls by 46 Ibs (15%)
This is a method of gaining a few extra Ibs at a ver
nominal cost.






10. Extension demonstrations and research trials have
shown that in Florida the "forced use" of dustbags
(table 3) is the most economical and effective way
of controlling horn flies and lice. This technique
requires that either the water or mineral station be
fenced off (figure 1) so that the animals are forced
to go through a 5 foot opening which has dustbags (s)
suspended in it. Yearlings have been shown to gain
1/3 of a Ib per day more than controls who were
sprayed in a conventional manner.
This data was gathered in cooperation with Dr. Phil Koehler, Extension Entomologist.
Summary
In a total management plan, all phases of the
production cycle must be included and flexibility
included to allow for variations that will occur. This is a
challenging task with profit or loss at stake. Use of your
land resource at its best and most efficient capacity is
needed. Some of the fundamental cow herd


management steps3 are (1) a sound year-round
nutrition program that is economical, (2) good cattle
handling facilities, (3) marketing program based on
capitalizing on your breeding, (4) use superior sires in
adequate numbers, (5) short definite breeding season,
(6) grow your own herd replacements, (7) cull open and
poor producing cows, (8) develop and follow a
comprehensive herd health plan, (9) take advantage of
growth stimulants, and (10) make use of some means of
controlling external parasites.
1 Prepared by Robert S. Sand, Ph.D., Associate Professor, Extension Livestock
Specialist, IFAS, University of Florida.
2 Use of trade names in this publication is solely for the purpose of providing
specific information. It is not a guarantee or warranty of products named and
does not signify approval to the exclusion of others of suitable composition by
the University of Florida.
3 Additional explanations and details on these and other topics of interest to
cattlemen are covered by Fact Sheets in the Southern Regional Cow-Calf
Handbook series and other materials contained in the "IFAS Beef Production
Handbook".


TABLE 1 EFFECT OF RALGRO IMPLANTa ON DAILY GAINS (LB) OF SUCKLING CALVES
AVERAGE DAILY GAIN BY TREATMENT
Length Total One Implant Two Non-Treated
b of Study no. Two Non-Treated
County Days Calves Early c Lated Implants Control
Polk 168 64 Steers 1.83 1.89 1.97 1.80
Levy 111 19 Steers 1.24 1.14
Okaloosa 92 10 Steers 2.23 1.92
Okaloosa 92 10 Heifers 1.84 1.66
Okeechobee 157 36 Steers 2.04 2.14 1.44
Hendry (#4) 1977 209 68 Steers 2.03 2.07 2.11 1.99
Hendry (#5) 1977 210 44 Steers 2.14 1.98
Hendry (#4) 1978 213 44 Steers 2.05 2.15 2.11 2.01
Hendry (#5) 1978 216 55 Steers 2.17 2.11 2.13 2.0
a. 36 mg
b. County in which cooperating ranch was located.
c. Implanted at the same time as the lirst implant in the two implant groups.
d. Implanted at the same time as the second implant in the two implant group.

TABLE 2 EFFECT OF RALGRO IMPLANTa ON DAILY GAINS (LB) OF YEARLING STEERS

AVERAGE DAILY GAIN BY TREATMENT
Length Total
of Study no. Two One Non-Treated
County Days Calves Implantsc Implant Controls
Polk (Pasture)d 117 152 1.79 1.57
Suwannee (Pasture) 190 52 1.3 1.1
Suwannee (Feedlot) 190 47 1.9 1.6


a. 36 mg Implant
b. Trial location


c. At 90 to 100 day intervals
d. (Program steers were on)


Table 3. Summary of dustbag demonstration results for external parasite control in Florida, 1976, 1977.
% Increase Lb/Day
% Control in Difference
Location (Horn Fly) Production (Treated-Check)
Polk County 95% 10% .09
Manatee
County 75% 26% .34
Alachua
County 99% 30% .25
Levy County 87% 72% .64
Palm Beach
County 69% 51% .36
Average 85% 38% .34

Figure 1. "Forced-use" Dustbag Arrangement
TOP VIEW MINERAL STATION OR WATER TROUGH


FENCE LINE














































































Cooperative Extension Work and Agriculture and Home Economics
(By acts of May 8 and June 30, 1914)
Cooperative Extension Service IFAS, University of Florida And United
States Department of Agriculture Cooperating
K. R. TEFERTILLER, DIRECTOR



FL-SGH


This printed material is made available through assistance from

[ I International Minerals & Chemical Corporation




1 COOPERATIVE EXTENSION SERVICE SOUTHERN STATES
31!


SOUTHERN REGIONAL


BEEF COW-CALF HANDBOOK

SR 1001

distributed by the Institute of Food and Agricultural Sciences/University of Florida
Applied Genetics
F A. Thrift and R. L. BreDahl, Department of Animal Sciences, University of Kentucky, Lexington 40506


Genetics is a branch of biological sciences that seeks
to account for differences and similarities exhibited by re-
lated animals. It is the application of Genetics to live-
stock improvement that forms the scientific basis of
Animal Breeding.
Inheritance is determined by particles called genes
which are carried on microscopic threads of living matter
called chromosomes. Chromosomes and genes occur in
pairs in the nucleus of body cells. Except for rare muta-
tions, one member of each pair of genes is an exact copy of
a gene in the animal's sire and the other member is a copy
of a gene in the animal's dam.
Although genes occur in pairs in individuals and pro-
duce effects in the individual that result from the com-
bined effect. of both genes of the pair, genes are trans-
mitted from generation to generations not in pairs but
singularly. In the formation of the sex cells (sperm and
Sovum), a reduction division takes place so that a copy of
only one member of the gene pair is contained in each
sperm or ovum. Thus, half of the sex cells of an indivi-
dual will be duplicates of a gene in his sire and half will be
duplicates of a gene in his dam.
When animals mate, the sex cells of the parents are,
in effect, paired in the body cells of the offspring. This
gene pair in the individual is his genotype for a particular
trait and the genotype determines the kind of sex cells the
individual can produce and, consequently, the inherit-
ance he can transmit to his offspring.
Important as genotypes are to cattle breeders, they
are seldom known, except possibly for a very few simply-
inherited traits, because genotypes are not visible. What
we observe when an animal is evaluated with respect to a
particular trait is called the phenotype. Phenotypes may
confuse breeders because it is often true that animals with
similar phenotypes have different genotypes. It is the
phenotype of an individual that is observed, but it is the
genotype that is important to the cattle breeder.
To ilustrate the application of Genetics to cattle
breeding, a simple example involving a genetic abnorma-
lity will be utilized. Although the exact mechanism by
which many genetic abnormalities are inherited is not
known with certainty, the following description suffices
to explain most of the variability observed for various
genetic abnormalities which are controlled by a single
pair of recessive genes:


Genotype
DD
Dd
dd


Phenotype
Normal (Non-carrier)
Normal (Carrier)
Abnormal


As illustrated, there are three possible genotypes in-
volved for a trait controlled by a single gene pair and these
genotypes are specified as DD, Dd, and dd. However,
only two phenotypes, normal and abnormal, are distin-
guishable. The D gene is said to be dominant since it ob-
scures the proPsPnce of the d gene in the Dd genotype. The
d gene is called the recessive gene. When both members of
the gene pair are alike, the genotype is said to be
homozygous for the trait; whereas, if both members of the
gene pair are unlike, the genotype is said to be heterozy-
gous. In the example, DD and dd are homozygous geno-
types and Dd is the heterozygous genotype. Further, geno-
types, DD, Dd and dd are said to be homozygous domi-
nant, heterozygous and homozygous recessive, respec-
tively, because the D gene is dominant over the recessive d
gene. Since the D gene is dominant over the d gene, the
phenotypes of DD and Dd cannot be distinguished. The
heterozygous individuals (Dd) are often referred to as
carriers since, although they appear phenotypically
normal, their genotypes carries the recessive gene. Conse-
quently, heterozygous individuals can produce two kinds

I JL II 1
I ~~.,


---- "---------------- - -- ---

Figure 1. Dwarf Hereford X Angus crossbred calf
resulting from mating of carrier bull with
a carrier cow.


1001.1







of gametes; however, homozygous individuals can pro-
duce only one kind of gamete.
Homozygous recessive individuals have abnormal
phenotypes such as that illustrated in figure 1 for dwarfism.
These abnormal individuals can be culled if they survive
to breeding age, so no big problem results except lowered
value of the affected animal and, perhaps, bad publicity.
The real problem occurs when individuals which are
carriers of an abnormality such as dwarfism are used for
breeding since, on the average, these individuals will
transmit the undesirable recessive gene to half of their off-
spring.
When a carrier (Dd) bull is mated to a large group of
non-carrier (DD) cows, the results illustrated in figure 2
are expected. The carrier bull can produce two types of
gametes in equal numbers (D,d); whereas, the non-carrier
cows can produce only one type of gamete (D), As illu-
strated, all of the resulting progeny will be phenotypic-
ally normal, but half of the progeny are expected to be
carriers of the undesirable recessive gene. Thus, on the


.AKKRtK NON-CARRIER CARRIER CARRIER
LF CALF CALF. CALF

50 % 50 %


Figure 2. Results expected, on the average,from mating a
carrier bull to non-carrier cow.
average, the carrier bull is expected to transmit the unde-
sirable recessive gene to half of his progeny and it is
strictly a function of chance as to which offspring receive
the recessive gene.
Another situation can exist when a carrier (Dd) bull
is mated to a large group of carrier (Dd) cows and is illu-
strated in figure 3. On the average, the progeny would be
expected to occur in a ratio of 1:2:1, that is, I phenotypic-
ally normal non-carrier, 2 phenotypically normal carriers
and 1 that expresses the genetic abnormality. Just as an
example, the one progeny that expresses the genetic ab-
normality would be a dwarf such as that illustrated in
figure 1. When two phenotypically normal parents pro-
duce a calf that expresses a specific genetic abnormality, it
is known that the bull that sired the calf and the cow that
produced the calf are both carriers of the genetic ab-
normality. Thus, the calf that expresses the genetic ab-
normality together with its sire and dam should be culled
from the breeding herd.


CARRRRIER d D d D





NON-CARRIER CARRIER CARRIER ABNORMAL
CALF CALF CALF CALF
25 % 50 % 25 %


Figure 3. Results expected, on the average,from mating a
carrier bull to carrier cows.
Testing to Detect Carriers of Abnormalities
Now the situation may arise in a herd where a pro-
ducer has a bull which appears phenotypically normal but
it is not known whether the bull is a carrier for one or
more genetic abnormalities. Are there mating proce-
dures which can be utilized to evaluate whether the bull is
a carrier for a specific abnormality? If a genetic ab-
normality can be expressed by both sexes and is known to
depend upon a single recessive gene (that is, individual of
genotype dd express the genetic abnormality, while
individuals of genotypes DD and Dd are phenotypically
normal), then several mating procedures are available for
testing a phenotypically normal but genotypically
unknown (DD? or Dd?) bull to see if he is a carrier of the
undesirable recessive gene.
Sire-Daughter Matings: If a bull is mated to a
random 35 of his daughters and 35 fertile matings result,
the probability of failing to detect the bull to be a carrier if
he is a carrier of an undesirable recessive gene equals .01.
In other words, if the bull is a carrier of an undesirable
recessive gene, the probability that he will produce all
phenotypically normal progeny when mated to 35 of his
daughters equals .01. The probability value is obtained
from the expression, (7/8)35 = .01, and the probability
value can be changed by varying the number of matings as
illustrated in table 1. This testing procedure has the ad-
vantage that a bull is tested simultaneously for presence of
all undesirable recessive genes that he may carry; how-
ever, it has the principal disadvantage that the bull will be
somewhat advanced in age before progeny from the sire-
daughter matings are available for observation. Also, this
mating procedure results in progeny that are 25% inbred.
Normally inbreeding coefficients as high as 25% are
undesirable, particularly if the sire is not regarded as
being genetically superior.
Half-Sister Matings: The sire-daughter probability
values in table 1 also apply when a sire is mated to a
random 35 of his half-sisters; however, in this case, it is


1001.2





TABLE 1. PROBABILITY OF FAILING TO DETECT A SIRE AS A CARRIER
OF A RECESSIVE GENE FOR THREE MATING PROCEDURES

Mating Procedure

Number of (1/2)N (3/4)N (7/8)N
Offspring Mating Sire to Mating Sire to Known Mating Sire to
Produced (N) Affected Females Carrier Females His Daughtersa


1
2
3
4
5
6
7 P = .01
8
9
10
11
12
13
14
15
16 P = .01


28
29
30
31
32
33
34
35 P = .01


.5000
.2500
.1250
.0625
.0313
.0156
.0100


.7500
.5625
.4219
.3164
.2373
.1780
.1335
.1001
.0751
.0563
.0422
.0316
.0237
.0178
.0134
.0100


.8750
.7656
.6999
.5862
.5129
.4488
.3927
.3436
.3007
.2631
.2302
.2014
.1762
.1542
.1349
.1180
.1033
.0904
.0791
.0692
.0606
.0530
.0464
.0406
.0355
.0311
.0272
.0238
.0208
.0182
.0159
.0139
.0122
.0107
.0100


a
Also applies to situations where an individual is mated either to a random sample of his half-sisters or to randomly selected dau-
ghters of a known carrier sire. For the former mating scheme, the assumption is made that the common ancestor that sired the in-
dividual and his half-sisters was a carrier of the recessive gene.


necessary to make the assumption that the common
ancestor that produced the sire and his half-sisters is a
carrier of the recessive gene. This mating procedure
results in progeny that are 12.5% inbred.
Mating to Daughters of a Known Carrier Bull: The
S sire-daughter probability values in table I also apply to
the situation where a sire is tested by mating him to 35
randomly selected daughters of a sire that is known to be a
carrier of a specific recessive gene. This mating proce-


dure may or may not involve inbreeding depending on the
relationship between the sire being tested and the
daughters of the carrier bull.
Mating to Known Carrier Cows: The fourth mating
procedure by which a bull can be tested for presence of an
undesirable recessive gene involves mating a bull to
known carrier cows. If a bull is mated to 16 known carrier
cows and 16 fertile matings result, the probability of fail-
ing to detect the bull to be a carrier if he is a carrier of the


1001.3






undesirable recessive gene equals .01 which is obtained
from the expression, (3/4)16 = .01. As illustrated in table
1, the probability value can be changed by varying the
number of matings to known carrier cows..Mating a bull
to known carrier cows is a much more powerful test than
mating a bull to his daughters, his half-sisters or to
daughters of a known carrier sire because fewer matings
(16 vs. 35) are required to achieve the same level of prob-
ability. However, in contrast to mating a bull to his
daughters or half-sisters, this test applies only to a specific
abnormality instead of all abnormalities that a bull may
carry.
Mating to Cows Expressing the Abnormality: The
last mating procedure involves mating a bull to affected
cows (cows that show the genetic abnormality). If a bull is
mated to 7 affected cows and 7 fertile matings result, the
probability of failing to detect the bull to be a carrier if he
is a carrier of the undesirable recessive gene equals .01,
which is obtained from the expression, (1/2)' = 0.01, as
illustrated in table 1. Of the various mating procedures,
mating a bull to affected females is the most powerful
(fewer number of matings are required to achieve the
same level of probability) if the affected females are viable
and fertile; however, its application may be limited for a
genetic abnormality such as dwarfism, since a producer
would seldom have 7 dwarf cows that are fertile and avail-
able for breeding to a bull suspected of being a carrier of
the dwarf gene.
These different mating procedures can be utilized to
test a bull for any trait controlled by a simple recessive
gene. For instance, the polled-horned condition in cattle
can be illustrated as follows: PP=Pp=polled; pp = horns.
Thus a polled bull could be tested to see if he is a carrier of
the horned gene by mating him either to his daughters,


half-sisters, daughters of a polled bull sired by a horned
bull, polled cows that were all sired by a horned bull or to
horned cows. In this case, the preferred mating proce-
dure would be to mate the bull to the horned cows since
they would be viable and fertile with regards to the polled-
horned condition and only 7 fertile matings would be re-
quired to obtain the .01 probability level.
For the different mating procedures, only one calf
that expresses the genetic abnormality is required for
detection of a carrier bull. Since the values presented in
table I represent the probability of failing to detect a bull
if he is a carrier of a recessive gene, then I minus the values
presented in table I represent the probability of detecting
a bull to be a carrier of a recessive gene if he truly is a
carrier. Thus, probability of detection of a carrier bull
equals .99 if a bull sires calves from 35 randomly chosen
daughters, 16 known carrier cows or 7 affected cows. It
should be emphasized that these mating procedures can
be utilized to prove that a bull is a carrier of a recessive
gene; however, a bull can never be proven to not carry a
specific recessive gene.
Since the probability values presented in table I are
based on the assumption of 100% fertility where fertility
has reference to number of calves born as a function of
number of cows exposed, it should be kept in mind that
fertility rates of 100% are seldom realized in most beef
cattle herds. As a result, additional exposures are re-
quired to achieve the stated probability levels presented in
table 1. For instance, with a fertility level of 90%, 39
rather than 35 sire-daughter exposures would be re-
quired to get the 35 calves needed for the .01 probability
level. Thus, as the fertility level in a herd declines, more
exposures are required to obtain the desired probability
level.


COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acts of May 8and June 30,1914)
Cooperative Extension Service, IFAS, University of Florida
and United States Department of Agriculture, Cooperating
K. R. Tfertiller, Director


1001.4









SOUTHERN REGIONAL


BEEF COW-CALF HANDBOOK

SR-1002

distributedby the Institute of Food and Agricultural Sciences/University of Florida
Coping With Calving Difficulties
Duane Miksch, Extension Veterinarian, University of Kentucky


Causes of calving difficulty (dystocia) may be
separated into two categories. 1) Contributing causes can
be identified before the process of giving birth (parturi-
tion) begins. 2) Immediate causes are those that can only
be recognized after a cow is in labor. At that point
dystocia cannot be prevented; only the severity can be
minimized. However, the incidence of dystocia can be
reduced by management decisions based on understand-
ing the contributing causes.
Contributing Causes
The younger a heifer is when she calves, the more
difficulty she will have. Regardless of age at calving, the
highest incidence of dystocia is in first-calf heifers, and
second-calf cows have more dystocias than mature cows.
Birth size and shape are heritable. Sires can be
chosen to reduce calving difficulty. Using a sire breed
larger than dam breed in a cross-breeding program tends
to increase calving difficulty. However, within each breed
are bulls that contribute less difficulty than others. Ease-
of-calving data have been tabulated on some bulls used
widely in artificial insemination programs.
Level of nutrition plays an important role in deter-
ming age and weight at puberty and parturition. Most
heifers reach puberty before they are large enough to be
bred and calve without experiencing difficulty. Mal-
nutrition may result in an undersized or misshapen skele-
ton, including the pelvis. Over-feeding heifers during late
pregnancy to compensate for small size at breeding may
favor growth of the fetus, upsetting the balance between
fetal size and pelvic diameter. Excessive energy intake
may result in deposition of fat in the pelvic cavity, favor-
ing dystocia. An increased incidence of calves presented
backward in feedlot heifers has been observed. One pos-
sible explanation is that abdominal fat prevents reposi-
tioning of the fetus after some critical time during gesta-
tion.
Diseases that cause late-term abortion or fetal death
often result in dystocia. The dead fetus may be presented
abnormally or may be distended with fluid or gas.
S Maternal effects of abortion or fetal death include uterine
inertia, failure of the birth canal to dilate, and retained
after-birth (placenta). Previous injuries may result in a
misshapen birth canal or may produce pain during labor


that interferes with delivery.
Immediate Causes
A large fetus relative to the diameter of the birth
canal is the greatest cause of dystocia in heifers calving for
the first time. This also accounts for many calving diffi-
culties in second-calf cows and small cows bred to bulls of
a larger breed. The other major cause of calving diffi-
culty, mal-position of the fetus as it approaches or enters
the birth canal, may occur in any cow regardless of age or
size. In animals that ordinarily have one offspring, there is
only one normal position of the fetus during birth: right
side up, front end first, feet and head extended.
Relatively infrequent causes of calving difficulty
include abnormalities of fetus or birth canal, failure of
birth canal to dilate, or failure of uterus or abdominal
muscles to contract effectively. These less frequent situa-
tions usually require professional assistance.
Normal Parturition
Normal parturition is arbitrarily described in three
stages. First stage begins with uterine contractions,
includes dilatation of the cervix, and ends with entry of
the fetus into the birth canal. Restlessness and isolation
from the herd may be the only observable signs during
this stage. Heifers are generally more restless.than older
cows. They may appear colicy, lying down and getting up
frequently or kicking at their abdomen. The first water-
bag may appear toward the end of the first stage. Stage-
one continues for two to six hours, or sometimes longer in
heifers.
Second stage comprises passage of the fetus through
the birth canal. During this phase the cow actively parti-
cipates in delivery. Fetal membranes appear and rupture
ahead of the fetus, providing lubrication for its passage.
Point pressure exerted in the cow's pelvis successively by
the head, shoulders, and hips of the fetus intensify
abdominal contractions. Mature cows are normally in
second stage parturition less than two hours. Heifers may
normally require three or four hours.
Once feet are showing, they should progressively
advance and not appear and disappear with each
abdominal contraction. If feet are protruding through the
vulva with soles down, they are usually front feet. If soles


1002.1









- ---- -

s ~~ ---C7 .-_ --


Normal anterior presentation


Anterior Presentation with Deviation of Head


- -i


Posterior Presentation


Breech Presentation


Figure 1. Variation of fetal presentation for birth. Reproduced by permission of S. J. Roberts, author,
from "Veterinary Obstetrics and Genital Diseases (Theriogenology)", 2nd Edition, 1971.


are up, they are usually hind feet. In a normal forward
delivery the front feet are side by side with jaws resting on
forelimbs and muzzle at about the fetlocks. The calf
passes through the birth canal in an arc. As it enters the
pelvic inlet, direction of travel is toward the tailhead of
the cow, then parallel to the cow's back, then ever more
ventrally. As the calf's hips enter the pelvis, direction of
travel is toward the cow's rear feet. This arc keeps the calf
high in the pelvic inlet and takes advantage of the widest
horizontal diameter of the pelvic opening.
Third stage includes passing fetal membranes and
closure of the cervix. The placenta is usually expelled
within eight hours, after which the cervix secretes a thick
mucus that helps prevent infection from entering the
uterus. Within 24 to 36 hours a person's hand will not pass
through the cervix; by four days only two fingers can- be
introduced.

Assessing the Need for Intervention
Limit the calving season to as short a period as


practical. With a short calving season it becomes more
practical to observe cows often enough to provide timely
assistance. It is important to have a calving watch so all
signs can be observed and help given when needed, with-
out interrupting normal parturitions for unnecessary
examinations. Record expected calving dates of indivi-
duals; this is practical only with artificial insemination or
hand breeding but is very helpful in determining which
cows to watch more closely.
Cattlemen should develop a competence and confi-
dence in determining when to intervene, in aiding
deliveries, and in assessing the need for professional
assistance. A cow should be examined if she has labored
two or three hours without progress or if the calf has not
been born within two hours after appearance of a water-
bag. Overzealous intervention before the cervix is fully
dilated may result in severe injury to the cow as well as the
calf.
A cow can be more easily examined when she is
standing. Lying down forces her abdominal organs and


1002.2


,- ----,
--~--- `~: \


- -- ------






the fetus into or against the pelvic cavity. Ifa cow will not
or cannot rise, it will help to position her upright on her
sternum and stifles with her rear legs extended behind her.
The vulva and surrounding area as well as the hands
and arms of the person making the examination-should be
washed thoroughly with warm water and soap. Cleanli-
ness at all times during examination and delivery cannot
be over-emphazized. Thoroughly lubricate the arms of
the examiner and the birth canal. Lubricating gels are
available commercially, or one can be prepared by dis-
solving mild soap flakes in a small amount of hot water
and allowing the solution to cool.
Carefully examine the birth canal to determine if it is
fully dilated and free of twisting and obstruction.
Evaluate the size of the fetus in relation to the diameter of
the passage. Pull on and pinch a foot of the calf to deter-
mine if it is alive. Examine the fetus to determine its posi-
tion and the presence of any abnormal structures. Normal
birth is possible only with the fetus in anterior or posterior
presentation, right side up, with head and limbs extended
(Fig. 1). The possibility of twins should always be con-
sidered.
Determine whether the feet presented are front or
rear feet. Front limbs have two joints between the hoof
and elbow, whereas rear limbs have only one joint be-
tween the hoof and hock. A cow is more apt to require
assistance with a posterior delivery than with an anterior
delivery. Rear limbs are not as effective in initiating
dilatation of the birth canal and stimulating abdominal
contractions as is the head, the tail head of the calf tends
to impact against the cows back bone, the hair of the calf
lies the wrong way, and compression of the calf's abdo-
men causes its rib cage to expand. With posterior
presentation, flow of blood through the navel cord is
impeded early in delivery, and the calf's head is sub-
merged in fluid. Once the hips enter the birth canal, deli-
very must be rapid for a live birth.
If examination reveals abnormalities of the fetus or
birth canal, failure of the tract to properly dilate, or a calf
apparently too large for safe delivery through the birth
canal, professional help should be sought at once.
Assisting the.Delivery
Provide adequate facilities and equipment for aiding
deliveries. A large well-lighted stall should be reserved as
a maternity area (Fig. 2). It should be sanitized and well-
bedded each time it is used.
Obstetrical chains are preferred to other traction aids
because they are more easily disinfected, and handles are
available that may be quickly attached anywhere along
their length. Two 30-inch chains, one 60-inch chain, and
two handles are desirable. Equipment should be cleaned
and boiled in mineral oil after use to prevent spread of
disease and rusting. Cotton sash cord works well but
should be discarded after use. A good mechanical calf
puller is needed, not for the amount of pressure it will
exert, but for the directions of traction that can be


Figure 2. Maternity stall with stanchion and swing-away
restraint panc!s.
achieved (Fig. 3). Other methods of applying traction,
such as block and tackle or fence stretchers, apply no
opposing force to stabilize the cow and allow pulling
parallel to her body only.


















Figure 3. Antiseptic lubricant; obstetrical chains
and detachable handles; fetal extractor.
Traction should be applied cautiously until the
vagina and vulva are fully dilated. Tearing the cervix or
vagina may result in sterility or death of the cow. The
whole purpose of the procedure is to deliver a healthy calf
and prevent injury to the cow.
If forced extraction is required, chains should be
placed carefully on the extremities. If fetal membrances
interfere, they should be torn away. Place the noose of the
chain above the fetlock and a half-hitch around the
jr::: --"-~---rrrL;;7---^-
o o----- --^

















pastern. This reduces the risk offracturinga boneor pull-
ing off toenails.
When one or both front or rear limbs or the head is
retained in the uterus, manipulation of the fetus is re-
retained in the uterus, manipulation of the fetus is re-


1002.3







quired before traction is applied. Fetal parts must be
guarded with the hand to avoid tearing the uterus. Some
manipulations can be made with one hand; others re-
quire opposing force. Opposing force is accomplished by
placing a loop of chain on a foot or the lower jaw and pull-
ing on the chain with one hand while repelling the poll,
shoulder, elbow, hip, or hock with the other hand. Care
must be taken that the teeth or toes do not tear the uterus.
Anterior Presentation
To apply traction to the head, pass the chain loop
over the poll behind the ears and through the mouth. This
causes the mouth to open, so care must be taken that the
calfs teeth don't lacerate the birth canal. Limit head trac-
tion on a live calf to relieving impaction of the head and
extending the neck; pulling on the head to move the body
may cause injury to the calfs spinal cord.
If the muzzle appears before one or both feet, the
elbow(s) may be impacted against the pelvic brim or the
forelimb(s) may be retained in the uterus. An impacted
elbow can usually be corrected by moderate traction on
the foot, however, it may be necessary to apply opposing
force to the head to make room for correction. If one or
both forelegs are retained in the uterus, it is often neces-
sary to push the head back through the pelvic inlet to
correct the problem. If it is very difficult to get the head
and both forelegs into the birth canal at the same time,
mechanical traction should not be applied. Either the
positioning is faulty or the passage is too small to accomo-
date the calf.
Shoulder lock occurs when the calfs shoulders be-
come impacted at the pelvic inlet. To relieve a shoulder
lock, apply moderate traction to the head and alternately
apply traction to the forelimbs so the shoulders are
"walked" through the bony pelvis one at a time. If the
shoulder lock is severe, a caesarian section should be con-
sidered; a shoulder lock relieved with difficulty may be
followed by a worse hiplock.
Hip lock (calfs hips impacted at pelvic inlet) should
be dealt with promptly. The calf usually doesn't survive
long in hip lock, and the cow may become paralyzed due
to excessive pressure on the nerves to her hind limbs.
Direction of traction is very important. If a hip lock
develops with the cow standing, fasten the forelimbs of
the calf together with a short chain, step up in the stirrup
formed by the chain, and swing your weight forward be-
tween the hind feet of the cow. Hip lock can often be
corrected in a cow lying down by repelling the fetus a
little, then applying traction over the uppermost rear leg
of the cow toward her shoulder. A chain can be placed
around the abdomen of the calf and traction applied
downward. A 450 rotation of the calf will aid in relieving a
hip lock because the vertical diameter of the pelvis is
greater than the horizontal diameter.
Posterior Presentation
A calf presented backward must be delivered back-
ward. It is not possible to turn a calf around in a cow.


Lubricate the fetus and birth canal before.delivery is at-
tempted. Place chains above the calfs hocks and attach
the calf puller before applying traction. Once the hips
enter the birth canal, traction should be rapid and
uninterrupted. Alternating traction on the rear legs and
rotating the fetus 450 may help. If it is very difficult to get
the hips through the pelvic inlet, a caesarian section may
be required. This decision should be made before the hips
are forced into the birth canal and the life of the calf
jeopardized.
If a calf is presented butt first (breech), the cow often
does not enter second-stage labor as point pressure is not
exerted within her pelvis to stimulate abdominal con-
tractions. The tip of the calfs tail may be protruding
through the vulva or lying in the vagina. The subtle signs
of first-stage parturition often go unrecognized, and the
cow appears sick or discharges a putrid fluid two or three
days later;
A breech presentation may be relatively easy or very
difficult to deal with. Important variables include how
soon the problem is recognized, whether or not the cow
will stand during manipulation of the fetus, the amount of
abdominal space for manipulation, how rigidly the calfs
hocks are extended, and how hard the cow strains.
The calfs hips must be repelled forward, upward,
and toward one flank, the hocks flexed, and the feet ex-
tended backward into and through the birth canal. It is
very helpful if the cow will stand during manipulation of
the fetus. The calf should be repelled between labor pains,
and care must be taken not to tear the uterus by pushing
too hard on the calf. If manipulation is difficult, epidural
anesthesia (a local anesthetic injected into the cow's spinal
canal) should be administered to stop straining.
Efforts by the cattleman to assist delivery should be
limited to thirty minutes, and should not exceed his
technical capabilities. To delay calling a veterinarian
when his help is needed can result in unnecessary injury or
death of the cow as well as the calf.
After the Delivery
Provide adequate aftercare for the calf and its
mother. Two emergencies may exist upon completion of
the delivery: the calf may fail to breathe, and the cow may
attempt to prolapse her uterus. The calf can be stimu-
lated to breathe by inserting a straw 2 or 3 inches into the
nostril, by brisk massage, and by slapping the chest.
Excess mucus should be cleared from the airway, and the
head kept lower than the chest until the calf is breathing.
Brisk massage with a rough cloth, such as burlap, will also
stimulate circulation. Commercial aspirator-respirators
are available and are helpful in aspirating mucus and ad-
ministering oxygen. Directions provided by the manu-
facturer should be followed.
The cow should be encouraged to get up and move
around so her uterus will fall into the abdomen and labor
will cease. Straining can sometimes be interrupted by
vigorously gripping the cow's spine at the middle of her
back. Examine the reproductive tract for tears and the


1002.4






presence of another calf.
After emergencies are averted, saturate the calf's
navel with an iodine solution. Within fifteen minutes after
S birth, the calf should nurse the cow or be given a quart of
colostrum by nipple or esophageal feeder. Inject cow and
calf with broad spectrum antibiotics. Avoid putting
boluses, especially those containing urea, in the uterus.
They are irritating to uterine mucosa and may result in de-
layed conception. If the placenta is retained, continue to
administer broad-spectrum antibiotics daily until it is
passed. If the cow goes off feed or in any other way
appears sick, consult a veterinarian.


Conclusions

The incidence and severity of dystocia can be re-
duced by sound management decisions in breeding, nutri-
tion and herd health. Some calving difficulties will occur
regardless of precautions taken. Losses from dystocia can
be minimized by 1) close observation of cows during
calving, 2) recognition of a need for intervention, 3) provi-
sion of suitable handling facilities, 4) technical capability
to aid delivery, and 5) judgement to seek professional
assistance promptly when indicated.


COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Act of May 8 and June 30, 1914)
Cooperative Extension Service, IFAS, University of Florida
and United States Department of Agriculture, Cooperating
K. R. Tefertiller. Director


1002.5









SOUTHERN REGIONAL


BEEF COW-CALF HANDBOOK
SR1003


distributed by the Institute of Food and Agricultural Sciences/University of Florida
Factors Affecting Calf Crop
Percentage
Dr. Michael J. Fields, and Dr. Alvin C. Warnick, Department of Animal Science, University of Florida.
Gainesville, Florida


Introduction
Reproduction in cattle is the single most important
factor affecting "Percent Calf Crop" and, thereby, deter-
mining the profitability of a cow-calf program. In many
areas of the Southeast, there is reportedly only a 70% calf
crop (% Calf Crop= no. cows weaning a calf+ no. cows in
breeding herd). Approximately 1/4 of the cows are not
contributing to the ranch income. Adjacent ranchers have
found a wide divergence in reproduction rates primarily
reflecting the result of differences in management. High
reproduction rates can be obtained in any area of the
Southeast by following good production and manage-
S ment practices.
The following emphasizes many factors that are of
primary importance in management practices for in-
creased percent calf crop to provide additional ranch
income.

Identification of Calf Losses
Various factors influencing the percent calf crop
weaned were compiled from the U.S.D.A. Beef Cattle
Experiment Station at Brooksville and the Beef Re-
search Unit at Gainesville, Florida, from 1951 to 1973 as
shown in Table 1. It is clearly demonstrated that the most
significant factor contributing to a reduction in calves
weaned was the 21% of the cows that failed to become
pregnant. Other factors negatively influencing % calf crop
weaned accounted for only 5.8% of the failures. This is in
agreement with similar trends for the Southeast (Temple,
1966).
The largest proportion of these losses were shown to
occur in the first calf heifer regardless of whether she was
a two or three year old (Crockett, 1973). This is shown to
carry over into the 3rd breeding season; most likely result-
ing from the heifer in many cases having been bred near
the end of the second breeding season, calving late and
thus completely missing the third breeding season. After
the heifers recover from these first two calving
experiences, as a group, they continue to increase in
reproductive efficiency, particularly, if a strict culling
program is observed.


Table 1. Factors Influencing the % Calf Crop Weaned


Factors


Cows open at palpation
(pregnancy failure)
Calves lost during gestation
(palpation to calving)
Calves lost at birth
Calves lost during first
4 days postpartum
Calves lost 4 days after birth
to weaning
Calves weaned
Total possible calves:
% Calf crop weaned:


1,961 21.2%

79 .8%
191 2.1%

80 .9%

190 2.0%
6,756
9,257
73.0%


The primary reason for this low reproduction in
young heifers is inadequate nutrition following weaning,
especially during the winter period. Heifers which do not
have adequate growth are delayed in reaching puberty. If
growth is not attained prior to calving, the heifer will
attempt to acquire the growth during the course of
nursing her first calf. This is compounded by the need for
the nutritional level to be maintained for the postpartum
(post-calving) nursed cow to recycle and breed during the
subsequent short breeding season. These additional nutri-
tional requirements are necessary for the first calf heifer
to perform all of the body functions of a mature cow such
as lactation (milking) while at the same time maintaining
growth. This problem is further compounded by the fact
that the heifer may be shedding incisor teeth and has a
limited capacity for grazing.
Wiltbank (1969) reported that two to three year old
first calf heifers exhibited first estrus after calving 20 to 30


1003.1








days later than the mature cows. This is seen in Table 2
where 90% of the older cows were in heat by day 70 post-
partum versus only 65% of the animals two to three years
of age. It was 100 days following calving before 90% of the
two and three year olds were in heat.
Table 2. Percent Cows in Heat at Varying
Intervals Following Calving (Whitbank, 1966)

Days After Calving

Age of Cow 40 50 60 70 80 90 100 110

%%%%%% % %
4 years 55 70 80 90 90 95 100 100
or older
2-3 15 30 40 64 80 80 90 90
years old

These data show that most losses (21%) occurred in
the cow that was open at pregnancy determination
following the breeding season. The greatest reduction in
fertility occurred in first-calf heifers during the second
and third breeding season.
Suggestions for Reducing % Open Cows
Factors Determining Puberty in Heifers
In the future, more heifers are going to be bred at 13
to 15 months of age to calve at two years of age to take ad-
vantage of the approximately one calf increase in the life-
time production if management can improve rebreeding
efficiently during the second and third breeding season.
This calls for having the heifer reach puberty and be bred
at an early age and thus preventing the decline in preg-
nancy rate following the first calving. In most all cases,
Table 3. Age of Puberty In Heifers on
Two Levels of Nutrition (Bellows, 1967)

Percent in heat by months

Regime and
Breed 11 12 13 14 15 16 17
Breed


Low level
Angus
Hereford
Angus X
Hereford
High Level
Angus
Hereford
Angus X
Hereford


0 0 0 33 82 90 100
0 11 22 33 38 50 100
0 0 12 68 85 100 100


0 33 58 100 100 100 100
0 12 50 100 100 100 100
0 18 76 94 94 100 100


the following suggestions will apply whether heifers are to
be bred to calve first at two or three years of age.
Table 3 shows the effect of nutrition on first expres-
sion of estrus in heifers.
These heifers following weaning were wintered on either a
low level feeding regime to gain .8 lb/day or on a high
level to gain 1.6 lb. In this particular group of heifers,
breeding at 14 months of age would have resulted in a low
pregnancy rate.for the low level feeding regime subgroup
since only 33% of these heifers had cycled at that time.
Whereas, in the high level feeding regime, 100% of the
heifers were in heat by 14 months of age. It is interesting to
note the crossbreds cycled earlier and responded more
favorably on the low level of nutrition than purebreds.
This was no doubt partially due to the effect of hybrid
vigor on weight gains and overall earlier maturity. The
probable reason for the delayed estrus or puberty in the
group on the level of nutrition was that heifers had not at-
tained the weight of heifers on the high level. This
information indicates that heifers do not reach puberty
until they have sufficient weight as seen in Table 4.


Table 4. Weight at Which Heifers Reached
Puberty (Wlltbank, 1972)

Percent In heat before
Breed 500 Ib 550 Ib 600 Ib 650 Ib 700 Ib 750 Ib

Angus 8 44 72 84 88 100
Hereford 0 0 27 50 62 88
Angus X 0 18 43 68 78 93
Hereford

Few heifers reached puberty prior to attaining 600 lb.
weights, and a 650 lb. weight was necessary for at least
50% of the heifers to have reached puberty in these breeds.
Thus, age alone may not be as accurate an indicator for
breeding heifers as a combination of weight and age. It
would be prudent not to breed heifers at a light weight
since any advantage is often costly in terms of subsequent
calves and possible losses from calving difficulties.
Puberty occurs much later in heifers of Brahman
breeding than reported for the Hereford and Angus
heifers of the above studies. It has been shown, however,
that age of puberty can be decreased in cattle of Brahman
breeding through improved management and planned
mating systems.
Breeding heifers to calve at two years of age offers the
added advantages of initiating a selection program for
early maturity coupled with a rapid growth rate. The late-
maturing, slow growing animal will be eliminated due to
her inability to breed in a short breeding season. How-
ever, initially in this type of earlier breeding program a
large number of replacement heifers will be needed due to


1003.2








difficulty of selecting at weaning heifers which will cycle
S early. Thus, the need for a good calf crop is emphasized so
you have sufficient heifers to select for replacements. Cull
only the tail-end (light weight, poor quality) heifers at
weaning. There is usually a good market for the open
yearling heifers. Although, the emphasis is on breeding.
heifers to calf at two years of age the management
practices discussed apply equally to breeding to calve at
three years of age.
Shortened Breeding Season
A short breeding season (60-90 days) allows a cattle-
man to take advantage of technological developments as
well as efficiently utilize feed and labor resources. The
season of breeding should be determined based on the
local climatic conditions and time of maximum forage
quality and quantity. However, if a producer prefers
having marketable animals year round, management can
be altered to provide two controlled breeding seasons a
year. However, it must be remembered that in every
operation there is a single date or season (depending on
environmental conditions, i.e., availability of high quality
forage) at which calves born at that time will make their
most profitable gains. Calves born earlier will not neces-
sarily have heavier weights even though they are older and
younger calves will not weigh as much as those born at the
optimal time of calving. Remember, we are not selling ad-
justed 205-day weights but total calf weight at weaning. A
S short breeding season will allow an operation to take ad-
vantage of its optimal calving time.
Actually, there are data that indicates advantages in
having a 42-day breeding season (2 estrus cycles). A
breeding season longer than 90 days is futile both in that
cows conceiving after this time are few and also have a
tendency for failure to settle the next year. In addition,
these late calving cows wean light calves. Thus, it would
be better to replace this animal with a more productive
pregnant heifer.
One of the best ways to assure a reproductively
sound herd of cattle is by starting the heifers calving 20 to
30 days earlier than the cows. In the southwest region,
cattle tend to have a calving interval longer than 12
months. If the cow is pregnant 285 days, this leaves only
80 days to rebreed and at least 50 days of this will be used
to involute (return to normal size) the reproductive tract.
This leaves only 30 days for the animal to show heat and
rebreed in order to calve every 12 months.
Many cows, however, take longer than 80 days to re-
breed after calving. If the cow was bred late the first
breeding season, subsequent breeding will eventually lead
to the first estrus post-calving occurring after the short
breeding season.
There are two ways to counteract the serious losses
S occurring in first calf heifers. First, start the heifers early
Enough in their first breeding season so as to give them
time to "mend" and rebreed following their first calf and,
second, provide an adequate nutritional program, parti-
cularly for the cow following calving.


If difficulties are still encountered in getting these
heifers to cycle their second breeding season, considera-
tion may be given to early weaning of the calves. Early
weaning of calves removes the stress of lactation enabling
nutrients to be used for growth and reproduction. This
may be particularly advantageous during times of
extreme environmental stress, ie., drought, cold winters
and hurricanes.
Table 5 indicates that cows 'bred the first estrus
following calving or soon thereafter are not as fertile as
cows that have a longer time to "mend". Heifers bred 20
days early have 20 days longer for the reproductive tract
to return to normal following calving. This is reflected in
the increased pregnancy rate.
Table 5 demonstrates that animals having a shorter
interval from calving to start of breeding have a lower
pregnancy rate on first service than those having a longer
interval from calving to start of breeding, 33 versus 62%,
respectively. This shows that the first estrus following
calving is less fertile than subsequent heats. This may be
particularly true in the case of first calf heifers where a
heavy demand for energy is necessary for growth and
lactation. Florida data shows that limited nutrition nega-
tively influences reproduction before inhibiting growth
and lactation, particularly in cattle with Brahman breed-
ing.

Table 5. Time of Calving and Conception Rate
(Wlltbank, 1972)
Avg. No. Days From Cows
Calving Date Calving to Start of Conceiving
Breeding (May 1) First Srvice

Feb. 10-Mar. 1 70 days 62%
Mar. 2 Mar. 21 50 days 58%
Mar. 22- Apr. 10 30 days 33%
Apr. 11 -May 1 10 days 33%

Not only does the data show that breeding heifers
early improves reproduction but there is also another
economical advantage. Cows bred early in the optimal
breeding season wean heavier calves, when there is a
single date for weaning.
Figure 1 shows that the further into the breeding
season the cow progresses unbred, the lighter the calf she
weans. Cows bred the first 20 days of an 80 day breeding
season produced nearly 100 pounds more calf than those
calves produced from breeding the last 20 days. Each 21
days that a cow is in the breeding herd and not bred, she is
cutting into the profit. However, this is just the obvious
part of the picture, for the loss is magnified next year
when the late calving cows do not rebreed. This is a result
of the short interval from the time the calf is born until the
next breeding season.


1003.3








Figure 1. Effect of Time of Breeding Upon
Subsequent Average Weaning Weight of Calves
(Burns, 1973)


450

Average Wt. 400


of Calves

at Weaning


350

300

250

250


First Second Third Fourth
20 days 20 days 20 days 20 days

Time Cow Conceived From Start of Breeding Season

The best approach to having the cow herd calve early
is to start the heifers early as reported above. In addition,
an adequate nutrition program is necessary particularly
for the young (lactating or suckling) cow.
Nutrition Postpartum
Nutrition has a two fold effect on achieving success-
ful pregnancy in the postpartum (lactating) cow. First,
sufficient levels are necessary for animals to show heat
after calving and second, there is the additional require-
ment for maintaining pregnancy in the early stages.
Cows should be gaining weight (0.5 lb/day) during
the breeding season. The price-cost squeeze makes it
imperative to look for alternatives in feeding cattle during
the winter following weaning or calving. In the Southeast
one possibility is the grazing of White Dutch clover and
grass combinations where the soil and moisture condi-
tions permit. The primary advantage of the clover-grass
combination as seen in Table 6, was the 82% versus 48%
pregnancy rate in the lactating cows and was further
reflected in the. interval from calving to first heat of 72
versus 90 days. Due to the moisture requirements for
clover, it may be that winter grazing of annuals, i.e., rye or
oats would provide similar favorable results. Adequate
research data on this question is unavailable.
It was further reported that winter grazing of heifers
on a clover-grass combination resulted in just as favor-
able increase in reproduction as supplementation with
cottonseed meal. Overall replacement crossbred heifers
raised on clover-grass pastures had a 15% higher preg-
nancy rate than half sisters raised on straight grass. This is
particularly significant with the relatively high cost of
feed.


Table 6. A Comparison of Reproduction in
Commercial Cows on Clover-Grass
Versus Grass Pastures (Warnick, 1969)

Criteria Clover-Grass Grass

Acres per cow 1.33 2.00
% pregnant, lactating 82 49
% pregnant, non-lactating 100 93
% weaning, all cows 84 64
Internal calving to 72 90
first heat, days

There was little difference in pregnancy rate for the
non-lactating (non-nursing) cow whether she was on
clover-grass of pangolagrass alone. This suggests that
under adverse condition (i.e., drought) or an environ-
ment that prevents a high pregnancy rate, early weaning
of calves will possibly improve reproduction. It must be
emphasized that early weaning is suggested only as a
temporary measure. The cause of a low pregnancy rate
should be dealt with directly to enable the producers to
take advantage of a favorable environment in the South-
east for weaning heavier calves.
Improved Reproduction by Culling Open Cows
Cows should be eliminated from the herd if they fail
to conceive during a short breeding season. In a classical
study with Florida (Brahman X Florida Native) native
cattle purchased in south Florida, it was demonstrated
that removing open cows from the cow herd had a dra-
matic subsequent effect on increasing reproductive per-
formance (Table 7).
Table 7. Effect of Culling Open Cows on subsequent
Reproduction of the Cow Herd (Koger, 1973)
Year % Pregnant Weaning Wt. (Ibs.)

1953 44 350
1954 55 415
1955 82 432
1956 86 428
1957 88 431
1958 88 422
1959 92 406
1960 to 1964 94 508

Part of the advantage in culling open cows is the im-
proved nutrition available to the remaining pregnant
cows, improved management and changes in the genetic
composition of these cows. It must be emphasized that if
management is poor, the cow will not have an opportu-
nity to express her genetic ability to reproduce. Selection
in this case against open cows will not be effective. An
open cow consumes at least the profit of one weaned calf.
Identifying the open cow through pregnancy examina-
tion 60 days following removal of the bulls will at least


1003.4


44







recover some of the cost incurred that year and would
provide selection pressure for future generations against
subfertile animals.
Breeding heifers early and maintaining adequate
nutrition should minimize the "open cow" problem as
reported earlier. In addition, it also appears that the
ability of the heifer to conceive at an early age is an indica-
tion of an animal with a more efficient lifetime pro-
duction record compared to those animals not pregnant
from the first breeding season. This was verified as seen in
Figure 2.

Figure 2. Effect of Failure to Breed the First
Year in the Breeding Herd on Subsequent
Reproduction (Bellows, 1968)


Bred at 2 years of age
1,589 heifers


Bred
Average lifetime
% Calf crop
86%


Open
Average lifetime
% Calf crop
55%


All heifers were exposed to be bred at 2 years of age.
Heifers that failed to breed at 2 years of age were then
assigned to a group to be bred at 3 years of age. The life-
time performance of those breeding at 2 years was an 86%
calf crop compared with a 55% calf crop for those that
were open following the first breeding season. There is
comparable data available for animals bred as yearlings
to calve at two years of age.
The tendency in these heifers that do not breed their
first breeding season is to retain them for the next year's


breeding. The above argument tends to invalidate this as a
sound management policy. The same thing applies to
keeping open cows. In many instances, these animals have
become sterile; it is not a case of just not cycling during a
short breeding season.
Although little is known about the basic endocrine
system and physiology of reproduction of the beef cow,
we do have at hand a vast array of management tools that
should make poor reproductive performance in most
herds obsolete.
Summary and Recommendations
Females failing to conceive are responsible for some
80% of losses in the number of calves weaned per cows
bred. These losses can be minimized by selecting for those
animals pregnant following removal of the bulls by
culling open heifers and cows. Furthermore, adequate
nutrition in the form of White Dutch clover-grass
combinations or other winter feeding programs will result
in higher conception rates and heifers that reach puberty
at an earlier age.
Heifers should be wintered to gain approximately 1.0
to 1 1/2 lbs. daily if they are to reach puberty at 14 months
and be bred as yearlings to calve at two years of age.
Depending on breed, heifers should weigh at least 650 +
50 pounds at mating to minimize dystocia (calving diff-
culty) and loss of heifers. Select heifers to go into the
breeding herd based on their ability to become pregnant
at 12 to 15 months of age during a 60 to 90 day breeding
season. These heifers should be bred 20 to 30 days prior to
breeding the cow herd to give the heifer a longer period of
time to "mend" following calving, and, thereby, increase
the chances to rebreed the second breeding season. Breed
cows for 60 to 90 days, pregnancy check and cull those
that are open. To take further advantage of this type of
management, shorten the existing breeding season so
there will be a harvest of older calves of heavier weights at
weaning.
In adopting any or all of these management pro-
grams, none is meant to preclude the use of common cow
sense. Although, the emphasis was breeding heifers to
calve at two years of age the above management practices
apply equally to breeding to calve at three years of age.


COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
Cooperative Extension Service, IFAS, University of Florida
and United States Department of Agriculture, Cooperating
K. R. Tefertiller, Director


1003.5




,; COOPERATIVE EXTENSION SERVICE SOUTHERN STATES


SOUTHERN REGIONAL


BEEF COW-CALF HANDBOOK


SR1004


distributedby the Institute of Food and Agricultural Sciences/University of Florida

Selection And Culling Of Females
Paul E. Humes and John S. Sullivan, Jr.' Louisiana State
University


The value of performance testing for genetic
improvement of cattle populations has been proven by re-
search and demonstrated by cattlemen and is now widely
accepted by both the purebred and commercial segments
of the beef industry. Without performance records, no
objective selection and culling criteria are available so the
ensuing comments will be made on the assumption that
individual performance and cow production records are
available for the selection and culling processes.
Simply obtaining cow production and calf per-
formance records without correct application will not
lead to genetic improvement. Correct use of performance
records is made only when the superior animals are
selected for replacements based on their individual per-
formance and the inferior mature cows are culled based
on the performance of their progeny.
Selection of breeding animals is the major tool for
genetic improvement because it is the primary method by
which the breeder can change the average genetic merit of
his herd. The traits to be emphasized may vary slightly
from herd to herd, but to be included in a selection pro-
gram they must meet three criteria for genetic improve-
ment to occur. First, it must be economically important.
The economic net return realized is determined by the
amount and quality of the product produced from a given
set of resources. Both purebred and commercial pro-
ducers should include essentially the same traits in their
selection programs.
Second, for a trait to be included in a selection pro-
4gram, it should be moderately to highly heritable. With
moderate to high heritabilities (20% to 60%), accuracy of
selection based on individual performance records will be
sufficient to make adequate rates of genetic change within
a herd. However, selection accuracy will be maximized
only if the cattle are managed under uniform environ-
mental conditions so that observed differences reflect
genetic differences among the animals.


IAssociate Professor, Dept. of Animal Science, and Specialist
Cooperative Extension Service, respectively.


Third, sufficient measurable variation must be
present within a herd or breed for selection to be effective.
If a trait is highly heritable but only a small amount of
variation exists in the expression of a trait, the difference
in performance of the selected versus the herd average will
be minor and only small improvement can be expected in
the next generation of calves.
Fortunately growth traits (birth weight, weaning
weight and post-weaning growth) and carcass traits
(quality and yield grades) have high enough heritabilities
and exhibit enough variation to be included in a selection
program (table 1). Reproduction traits are lowly herit-
able and are not included in a selection program per se,
but must be a major reason for culling.


TABLE 1. ECONOMICALLY IMPORTANT
PRODUCTION TRAITS, THEIR APPROXIMATE
HERITABILITIES, THE AMOUNT OF EXISTING
VARIATION WITHIN A BREED, AND THE
EXPECTED GENETIC CHANGE FROM
SELECTION FOR EACH TRAIT

Expected
Trait Heritabllity Variation GeneticChange

Repro-
duction 0% High Low
Weaning Wt. 25% High High
Postweaning
gain 50% Moderate High
Carcass qual-
ity grade 50% Low Moderate
CarcassYield
grade 60% Moderate High


1004.1







Basically, female selection and culling consists of two
separate phases:
1. Replacement heifer selection.
2. Cow culling.
Because heifer selection and cow culling are performed on
two different populations (cows vs. calves) and different
kind of records are evaluated, it is necessary to discuss
them separately.
Selection of replacement heifers
The proportion of the heifer calves to be kept for
replacements will vary from herd to herd, depending on
the reproductive rate in the cow herd; whether the herd is
being expanded, reduced or maintained at a static size;
the average age of the cows in the herd, and other factors.
Due to death loss, age, infertility and low productivity, 15
to 20 percent of the cow herd is normally culled each year
and 33 to 50 percent of the heifer crop is retained as
replacements (table 2).


TABLE 2. PROPORTION OF HEIFER CALVES
TO BE RETAINED, BASED ON VARYING
REPRODUCTIVE AND CULLING RATES


Cow herd
Culling rate


Calf crop
weaned


% of heifers
retained as
replacement


% % %
15 90 33
15 85 35
15 80 38
20 90 44
20 85 47
20 80 50


Low culling rates in the cow herd permit more
intense selection to be practiced among the replacement
heifers (table 2). With a 15 percent culling rate in the cow
herd and a 90 percent calf crop weaned, only 33 percent of
the heifer crop is needed as replacements. However, with
a 20 percent culling rate and a 90 percent calf crop, 44 per-
cent of the heifers must be retained.
The expense and time involved in raising a replace-
ment heifer compared to increased rates of genetic
improvement through shortened generation intervals is a
point to consider in a commercial herd. In purebred herds
where shorter generation intervals are sought, 20 percent
or more of the cows are likely replaced each year.
A high percent calf crop weaned has a positive effect
on a selection program. With a larger percent calf crop
weaned, more selection intensity can be practiced and
greater selection differentials (difference between the
average performance of the replacement heifers and the
average of the group from which they were selected), can
be produced (table 2). The new result will be more rapid


herd improvement. This advantage is often overlooked
but is of considerable importance.
In a practical production situation, sequential selec-
tion should be practiced on replacement heifers, i.e.,
selections should be made more than once prior to the
time of first calving. The heifers should be evaluated
at: (1) weaning, (2) prior to first breeding, and (3) after
the first breeding season.
An occasional error will occur by culling some
heifers at weaning but because of the expense involved in
developing heifers to breeding age, it may not be feasible
to retain all the heifer crop to breeding age. Therefore, it is
suggested that the heifers with the lightest adjusted wean-
ing weights, obvious structural faults, inferior conforma-
tion, and those too small and too young to fit into the
breeding program, be culled at this time. The remaining
heifers should be fed to gain enough weight so that they
will be cycling regularly at 15 months of age. The post-
weaning gain necessary to reach puberty will vary from
breed to breed so no one recommendation is applicable to
all breeds.
Prior to the breeding season, another evaluation of
the heifers, based on 15 month weights, will determine
those too small to breed. These small heifers, lacking
growthiness, should be culled. By pregnancy checking the
heifers approximately 45 days after the end of the breed-
ing season, the open heifers can be identified and sold,
thus preventing additional costs for maintaining open
females that may be barren, infertile or have delayed
sexual maturity.
The use of sequential selection implies that more
heifers must be retained at weaning than would be re-
quired if final selections were made at this time. The extra
heifers to keep beyond weaning must be estimated, based
on anticipated postweaning growth and reproductive per-
formance. The percent of the heifer crop that must be re-
tained at weaning to offset further culling is outlined in
table 3. For example, if 40 percent of the heifer crop is
ultimately needed as replacements in the cow herd, and if
a 20 percent culling rate occurs from the time of weaning
until first calving, 50 percent of the entire heifer crop
should be retained at weaning.
Cow Culling
After a heifer becomes a producing cow in the herd,
she should be evaluated on her calf production records.
Once placed in the herd, the female is compared not only
to her contemporary herdmates, but to all cows in the
herd, regardless of age.
The most important criterion in culling a cow is her
reproductive efficiency. Cows that produce calves on an
alternate year basis or skip calving, should be culled first.
Culling infertile cows and those failing to wean a calf each
year will improve herd reproductive efficiency more than
any other management practice.
The second most important measure of cow pro-
ductivity is the weaning weight and weaning weight ratios


1004.2






TABLE 3. PROPORTION OF HEIFER CALVES
TO BE RETAINED AT WEANING
BASED ON VARYING POSTWEANING
CULLING AND REPLACEMENT RATES


%of Heifers Postweaning % of Heifers
Needed for Culling Retained
Replacements Rate at Weaning


35.3
37.5
40.0
47.1
50.0
53.3
58.8
62.5
66.7


of their calves. Weaning weight ratios are computed by
dividing the adjusted weaning weight of a particular calf
by the average for all calves within that weaning group.
Weaning weight ratios are the most useful measure of cow
preweaning productivity for within herd comparisons.
Because of yearly environmental fluctuations and be-
cause cows of different ages must be compared, ratios are
more practical that adjusted weaning weights for com-
147 paring cows of all ages within a herd.
Cow culling is often practiced, based on the average
weaning weight ratios of all calves produced by a cow.
Average weaning weight ratios are acceptable if all cows
have produced several calves. However, first and second
calf cows must also be considered in the culling process
and when only one or two calves have been produced,
average weaning weight ratios may not reflect the true
productivity of the young cow. To compare all cows on a
more nearly equal basis, most probably producing ability
(MPPA) values should be computed by the performance
testing organization and provided to the breeder.
The MPPA ranking of cows often differs from the
average weaning weight ratio ranking as illustrated by the
example in table 4. The six cows are listed from highest to
lowest based on average weaning weight ratios. When
MPPAs are used to rank. cows, considerable shifting
occurs. Among young cows, MPPAs tend to increase the
productivity measures of low producing cows and de-
crease the value for high producing cows. Although
MPPAs bring the production estimates of young cows
closer together, i.e., lowering the production estimate of
high producers and raising the estimate of lower pro-
ducers, they do not result in the culling of top cows and
retention of poor cows. Instead, the relatively low pro-
ducing young cow has an advantage over the low pro-
ducing older cow. Notice in table 4 that the average wean-


TABLE 4. COW PRODUCTIVITY COMPARISONS
ON THE BASIS OF AVERAGE WEANING WEIGHT
RATIOS AND MPPAs FOR
WEANING WEIGHT RATIO



Number of Weaning weight ratio
Cow calves Average MPPA

A 2 115.0 108.6
B 5 112.0 109.2
C 3 108.0 105.3
D 6 93.0 94.4
E 3 92.0 94.7
F 1 90.0 96.0


ing weight ratio for cow D was 93 percent on six calves,
while cow F had only one calf with a weaning weight ratio
of 90 percent. When MPPAs were calculated, cow F had a
higher production estimate than cow D; and thus cow D
would be culled before cow F. The use of MPPAs reduces
the errors in cow culling, particularly in young cows.
If postweaning progeny records are available,
yearling or long yearling MPPAs and weight ratios can
also be used in the cow culling program. Because male
and female calves are normally managed differently
following weaning, yearling or long yearling weight ratios
should be computed within each sex. This will allow a cow
producing a heifer calf to be fairly compared to one pro-
ducing a bull calf.



Conclusions
To maximize rates of genetic improvement by
selection and culling of females, the following
suggestions should be considered:
I. Traits that are emphasized should be economically
important, moderate to highly heritable and have
sufficient variation expressed to ensure response to
selection.
2. Practice sequential selection on heifers. Heifers
should be culled first at weaning, followed by
a second evaluation prior to the first breeding
season. Shortly after the first breeding season
a third evaluation would be made and all open
heifers culled.
3. Cull cows first on reproductive efficiency and
second, on weaning weight ratios. MPPA esti-
mates will ensure that all cows will be fairly
evaluated regardless of age. If available, post-
weaning progeny records can also be utilized.
4. Quality of calf is important. Each calf must be
of acceptable quality and conformation.
COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
Cooperative Extension Service, IFAS, University of Florida
and United States Department of Agriculture, Cooperating
K. R. Tefertiller, Director


1004.3




l COOPERATIVE EXTENSION SERVICE SOUTHERN STATES


SOUTHERN REGIONAL


BEEF COW-CALF HANDBOOK
L SR1005


distributed by the Institute of Food and Agricultural Sciences/University of Florida

A Controlled, Seasonal Cattle
Breeding Program

Clyde M. Triplett, Extension Animal Scientist, University of Georgia


Responses from beef cattle specialists in nine
southern states indicate that less than 30 percent
of the herds are on a controlled, seasonal breeding
program. These specialists further state that
summer-born (June-August) calves can be expect-
ed to be approximately 70 pounds lighter at wean-
ing than those dropped at other times. Some
studies have shown that nearly 40 percent of the
calves from herds on a year-round calving system'
are born in the summer. These figures illustrate
the tremendous economic loss resulting from sum-
mer-born calves.
The major reasons producers give for follow-
ing a year-round calving program are:
(1) Producers fear they will miss some calves if
they go on a controlled breeding program.
They say they would rather have a late calf
than no calf.
(2) They feel they can breed more cows to a bull
by breeding year-round.
(3) They feel it is too much trouble to confine
the bulls during the "off-season".
(4) They want to have calves for sale year-round.
Reasons for following a controlled, seasonal
calving program are:

(1) Culling and selection of replacements based
on production records can be better accom-
plished. To make meaningful comparisons
among brood cows, calves must be born with-
in a 90 to 120 day period. One of the main
criteria for culling cows is the relative per-
formance of their calves. Accurate compari-
sons between cows cannot be made if the
calving season is too extended. Acceptable
Performance implies not only weaning weight
but also that a cow produce a calf each twelve
months.
(2) Better care can be given cows at calving time.
Percent calf crop is the major economic fac-


tor in a cow-calf operation and care at calv-
ing time affects percent calf crop. It is very
difficult to properly check cows which are
on a year-round calving season.
(3) Herd health and management is facilitated.
There are many jobs which are important to
the health and management of a herd which
are more likely to be properly done if your
cows are on a controlled calving season.
Some of these practices are: vaccination, de-
horning, castration, identification, worming
and weaning. If a cattleman can perform all
these jobs at one time, it is much more likely
that they will be done and the labor require-
ment will be much less. Pregnancy testing
and culling open cows can greatly influence
percent calf crop and herd profits. However,
it cannot be conveniently carried on with
year-round calving.
(4) Brood cow nutrition can be improved. Winter
feeding of the brood cow is the most expen-
sive phase of cow-calf production. If some
of the cows are dry and some are nursing
calves during the winter, the herd cannot be
fed in the most efficient manner. Since cows
nursing calves require at least 50 percent
more protein than dry cows, neither group
can be fed properly if they are running to-
gether.
(5) Marketing or stocker-finisher operations are
improved. A calf crop which is uniform in
age and size can be marketed to a better
advantage. Large uniform groups of calves
will usually bring several cents per pound
more than those sold individually. If calves
are uniform in age, they will also fit into on-
the-farm stocker or feeding programs.
THE CALVING SEASON
A. Length of Season
A short breeding season (and therefore a short


1005.1






calving season) of 90 or less days is recommended.
In addition to the reasons for a controlled breeding
season already mentioned, a short breeding sea-


son is usually most profitable. Assuming a con-
stant weaning date, early calving cows wean heav-
ier calves than those calving late in the season.


TABLE I. EFFECT OF EARLY AND CONTROLLED BREEDING
ON AVERAGE WEANING WEIGHT
Assumptions Crossbred cows, weaning weight 480 pounds, birth weight 70 pounds and average
daily gain of 2.0 pounds. (480# W. W. T. 70# Birth wt. = 410# Gain- 205 days = 2.0# per day)


No.
Days


120
90
75


Avg.
Clvg.
Date


Wng.
Date


Avg.
Avg. Wng.
Age Wt.


3/1
2/15
2/7


Table 1 illustrates that a 75 day breeding sea-
son could be expected to produce an average in-
crease of 46 pounds over a 120 day breeding sea-
son if a constant weaning date was used. Even
though a 60 or 75 day breeding season is desirable,
a 90 day season is a more reasonable goal for
most producers. A 90 day season could 'produce
65 percent of the increase that a 75 day season
could achieve.
1. A Split Calving Season.
Some producers may prefer a split calv-
ing season. For example, a cattleman may
divide his cattle into two herds with one herd
calving in October, November, and Decem-
ber. The other herd might calve in January,
February and March. This system could pos-
sibly reduce the bull cost by enabling a pro-
ducer to breed more cows per bull. However,
better management and nutrition would have
to be given the bulls. A split calving season
might allow some producers to make better
use of feed supplies and to extend the mar-
keting season. The advantages of a controlled
calving season can still be realized in such
a system since both herds could be manag-
ed separately. The requirement for extra
labor and facilities should be considered for
a split season.
B. Time of Year for Calving
A general recommendation for season of calv-
ing in the southern states would be to avoid sum-
mer calves. Summer calves are those born from
approximately June 1 to September 1.
Calves born from September 1 through early
April may perform satisfactorily in the southern
states. The calving period 'which is most desirable
for a specific operation within the recommended
dates will be influenced by several factors. Some


of these factors and how they may influence the
desired calving season are:
1. Feed supply. The most expensive
phase of brood cow nutrition is the winter
feeding of lactating brood cows. This is a
factor favoring a late winter or early spring
calving for many operators. In areas where
winter annual pastures are well adapted, a
fall or early winter season may be desirable.
Young calves gain rapidly when their dams
are grazing winter annuals and cows usually
return in heat early.
2. Labor. The calving season requires
a relatively large amount of time and labor.
A cattleman with a diversified farming opera-
tion should consider the availability of labor
when setting the calving season.
3. Marketing or use of calves. The aver-
age relative price of calves at weaning or sell-
ing time is important in deciding on the calv-
ing season. For example, if feeder calf prices
are best in spring or early summer, then this
would favor fall dropped calves, providing
the extra value would offset the extra cost
of weaning such a calf. If calves are to be
backgrounded and/or finished, then a calv-
ing season to fit this schedule is important.
4. Weather. Certain areas within the
southern states have quite severe winters.
Thus, a calving season during the coldest
months would present some problems. Baby
calves may freeze or may get frostbite if born
during severe cold weather. Cold weather is
usually no problem in the lower coastal
plains area of the south.
A cattleman should consider the above men-
tioned factors and any others which may relate
to his operation in deciding on his calving season.


1005.2


Breeding
Season


4/1 to 8/1
4/1 to 7/1
4/1 to 6/15


Season







HOW TO START A CONTROLLED CALVING
SEASON

In most herds on a year-round calving season,
a natural calving concentration already exists.
Nutrition is the major factor responsible for brood
cows cycling and conceiving. Since pastures are
usually at their peak of quality in spring and early
summer, a natural concentration of calving may
occur in late winter and spring. No system of get-
ting on a controlled breeding program can com-
pletely eliminate the delaying of some cows from
their current calving schedule. However, by taking
advantage of the natural concentration in a herd,
the problem can be minimized.
A system for converting from year-round to a
90-day controlled calving season over a period of
three years would present less loss and fewer
problems than to try to convert in one year. The
following steps are suggested for getting on a
controlled breeding system:
(1) Build a good, strong bull pen or well-fenced
bull pasture. An electric fence in addition to
regular fence may be needed.
(2) Remove bull from herd. Select removal date
to coincide with latest date you want calves
born on your farm.
(3) Assuming fertile active bulls have been used
and that there were enough bulls with the
herd, sixty days after removing the bulls
from the herd (or at a convenient time near


this date), pregnancy check all cows and cull:
a) All non-pregnant dry breeding-age fe-
males which have been running with the
bull.
b) All non-pregnant cows with calves five
months of age or older.
(4) Put bulls back with herd the first year so that
calving season will be six months long.
(5) Start breeding replacement heifers 20 to 30
days ahead of the final long-range planned
breeding date for your herd. Put bull with
mature cows for six months the first year.
(6) The second year, follow the same system as
outlined in steps one to five except start
breeding so that calving season will be about
41/2 months long.
(7) The third year follow the same system as
outlined in steps one to five except start
breeding season so that calving season will
be 80 to 90 days. Also, cull all open cows
this year when pregnancy checking regard-
less of age of their calves. The breeding sea-
son may be reduced even further in follow-
ing years.
The following figures are designed to show
how the system could work. The example is
developed for a final long-range January to
March calving season. Dates could be chang-
ed to adapt to different desired calving dates.


COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
Cooperative Extension Service, IFAS, University of Florida
and United States Department of Agriculture, Cooperating
K. R. Tefertiller, Director


1005.3








THREE-YEAR PLAN FOR CONVERTING FROM YEAR-ROUND TO
90-DAY CALVING SEASON OF JANUARY, FEBRUARY, MARCH
(Assume year starts month bull is removed from herd)


FIRST YEAR

Remove Pregnancy Put bull Start Remove bull
bull check back.with breeding from replace-
June 20 Aug. 20 herd Dec. 22 replacement ment heifers
heifers Feb. 20 May 1


Jun J A S O N D J F M A M

SECOND YEAR

Remove Pregnancy Put bull back Remove bull
bull check with herd Feb. 1 from replace-
June 20 Aug. 20 Start breeding ment heifers
replacement May 1
heifers Feb. 20
1 A A
Jun J A S O N D JF M A M

THIRD YEAR

Remove Pregnancy Start Put bul Remove bull

June 20 Aug. 20 replacement herd Mar. 22 ment heifers
heifers Feb. 20 May 1


J F A M A


Jun A J A SA










SOUTHERN REGIONAL

1EEF COW-CALF HANDBOOK

SR1006


DETERMINING PREGNANCY IN CATTLE

A.M. Sorensen, Jr. and J.R. Beverly


Economic returns from the beef cattle industry de-
pend largely on the percent calf crop and the weaning
weight of calves to be sold.
The following discussion describes a way of improv-
ing the calf crop percentage through pregnancy deter-
mination and elimination of non-pregnant cows. This
determination, called palpation, is made by inserting the
arm into the rectum and feeling the reproductive tract
for pregnancy indications.

Equipment
Little equipment is needed in palpation. The in-
dividual doing the palpating should wear protective
covering on the arm and hand. This may be a rubber
sleeve or a plastic sleeve which covers the arm to the
shoulder. This protection guards against disease and
eliminates irritation of the arm. A lubricant, such as li-
quid soap, is preferred over detergent. Use a rubber
band to hold the plastic sleeve on the upper arm. Dry
rubber sleeves immediately after use and sprinkle with
talcum to avoid deterioration. Plastic sleeves may tear
after several uses, thereby reducing protection. Do not
attempt to use these later.
The chute for holding the animal during palpation
should allow the animal to stand on the ground in a nor-
mal position. It should have a front wall or gate and a
bar just above the hocks-in the rear, figure 1. This bar
eliminates the animal's kicking and protects the
palpator during manipulation of the reproductive
organs.


Figure 1. Chute arrangement for restraining cows.

*Profeor. Deprtmnt of Anrmal Sdeme. and Extenion animal reprodutlon spdelht,
Team AAM Univrnity.


Include an entrance gate in the chute at the rear of the
animal to allow entrance and exit for the palpator. Pro-
vide a gate which will swing across the crowding chute in
front of other animals coming behind the palpator.
Squeeze chutes may be used. However, the noise made
as the animal enters the chute and her unnatural posi-
tion sometimes excite the animal, making palpation
more difficult.
Palpation alone takes only a few seconds. The speed
with which pregnancy is determined depends largely on
management of the livestock as they come through the
chutes, stage of pregnancy and the palpator's ex-
perience. As many of 800 head of cattle can be palpated
in a normal working day under ideal conditions.
However, efficiency is greatly reduced if the palpator
must help bring the cattle into the chute, climb over the
chute wall to get behind the animal and then palpate the
animal.
Palpators should practice certain precautions. The
first of these concerns the palpator's safety. Restrain the
Animal so she cannot jump over the side of the chute or
kick the palpator. Prevent other cattle from coming up
behind the palpator as he attempts to determine
pregnancy.
Consider also the animal's safety. Do not place the
animal's head in a stanchion or headgate. This tends to
excite the animal. Replace broken boards in the chute
that could injure the animal's legs. A dirt floor chute is
most desirable. Animals in a chute with a slick floor
may become excited and lose their footing. Cleats across
the floor stabilize footing.

Reproductive System
Thorough knowledge of the female reproductive
system is essential in palpation, figure 2. The female
germ cell, called the ovum or egg, develops in a follicle
on the ovary, figure 3. The ovaries are suspended rather
freely in the body cavity by ligaments attached to the
top of the abdominal cavity. These move from one loca-
tion to another in the cavity.


1006.1





CARUNCLES


OVIDUCT


CORPUS LUTEUM


cow


OVARY


VAGINA
VAGINA


URETHRAL ORIFICE
URETHRAL ORIFICE


CLITORIS


UTERUS
UTERUS


Figure 2. Anatomy of the reproductive tract.


Figure 3. Large mature follicle on right ovary. Mature
corpus luteum on left ovary.

The ovaries (two) are located on each side of the cavi-
ty. They are approximately /2-inch wide, 3-inch deep
and 1-inch long in a normal cow. This size varies con-
siderably, depending upon-the stage of the estrous cycle.
The ovary should feel firm but not hard. The follicle
which contains the egg is a blister-like projection on the
surface of the ovary. It may reach a size of V2 to -inch
in diameter and protrude approximately 4-inch from
the surface. The follicle has the feel of a blister or tissue
filled with fluid. An experienced person can palpate the
follicle on the ovary.
As the follicle ruptures releasing the egg, the cavity
fills with cells to form another body, called the corpus
luteum, figure 3. This develops as a cellular mass and
protrudes with a teat-like projection at the point of rup-
ture. Approximately 15 days after the animal is in
estrus, the corpus luteum begins to regress and almost
1


completely disappears within the next 10 days. Another
follicle is growing and will rupture approximately 21
days after the previous one. This cycle pattern is follow-
ed at approximately 21-day intervals, figure 4. The cor-
pus luteum can also be palpated on the ovary by an ex-
perienced person.
ESTROUS CYCLE OF THE COW


Figure 4. Note the cycle pattern is followed at approx-
imately 21-day intervals.



--


Figure 5. Reproductive system of young cow, viewed
from inside of animal.
006.2


CERVIX



FOLLICLE









- Weight in pounds

o***** Length in inches


so 50


40


30
30


10.i .



2 3 4 5 6
Months of age, Bovine

Figure 6. Growth of fetus. Paturition occurs approx-
imately 280 days after fertilization.


The large follicle on the ovary indicates the animal is
approaching the time of estrus. A corpus luteum on the
ovary indicates the animal is in about the midpoint of
the estrous cycle or is pregnant. The corpus luteum per-
sists in the cow throughout pregnancy. Therefore,
palpation of the corpus luteum may either indicate a
stage in a normal cycle or pregnancy.


Figure 7. Reproductive tract of mature cow on the floor
of pelvis.
After the egg is released from the follicle, it moves in-
to the oviduct, a small tube that acts as a passageway for
the egg to go from the ovary into the uterus. The two
oviducts also act as sites of fertilization. The egg nor-


mally is fertilized about one-third of the way down the
oviduct by sperm that have entered during copulation.
The egg moves into the horn of the uterus and, if fer-
tilization has occurred, begins its cell division. The egg
continues to multiply and lay down its membranes, im-
planting itself in one of the uterine horns.
The cow's uterus is made up of two horns with a con-
necting body between, figure 2. Therefore, in develop-
ment of the membranes, they pass from the tip of one
horn through the body to the tip of the other horn. At-
tachment takes place throughout. The uterus is lined
with numerous raised prominences, called caruncles,
with form attachment points for developing cotyledons
or "buttons" on the fetal membranes. The next portion
of the reproductive tract toward the exterior is called the
cervix, figure 2, and is made up of a connective tissue
substance that feels much like gristle. The cervix is tor-
tous with folds protruding into the lumen and extending
in the direction of the exterior. Within these folds are
numerous glands which secrete fluid abundantly during
estrus. It becomes thick and tenacious during the func-
tioning period of the corpus luteum and during
pregnancy.
The next portion of the tract, the vagina, figure 2,
acts as a receptacle for the penis during copulation and
the point of deposition of the spermatozoa. The blad-
der, which opens on the floor of the vagina through the
urethral orifice, from this point to the vagina exterior
acts as a common passageway for urine and passage of
young at birth.
The vagina has the feeling of a thin-walled organ
similar to that of the uterus. The vulva is the external


1006.3





portion of the reproductive tract and may be seen as two
prominent lips.
The entire reproductive organs of an animal vary con-
siderably in size and feel with the stage of development
during pregnancy and also with the size and reproduc-
tive history of the animal. Generally, the size of the en-
tire nonpregnant reproductive tract is 12 to 18 inches
long. In young heifers that have just reached puberty,
the reproductive organs may be only 8 inches long. The
reproductive tract of older cows that have had several
calves may extend to 24 inches. Diameter of the uterine
horns is approximately 3 to 1 inch and the length of the
horns 6 to 8 inches with a 3 to 4-inch body. The cervix is
approximately 1 to 2 inches in diameter and 3 to 5 incheF
long.

Developmental Stages
Periods of development in a young calf's life are
divided into three parts. The period of the ovum is that
time from fertilization until the egg has divided enough
times to taken a particular form. This occurs about the
thirtieth day when there is an enfolding of the layers of
the developing egg. At this stage, the newly developing
animal is called an embryo. The period of embryonic
development lasts until attachment of the fetal mem-
branes to the lining of the uterus approximately 38
days. During the embryonic stage, various organs and
systems are laid down. These include the respiratory
system, nervous system, digestive system, circulatory


Figure 8. Separation of horns on the uterus.


system and reproductive system.
The embryo, as it develops, floats freely in the uterine
cavity, bathed by a secretion called uterine milk. During
this time, the embryo lays down all of the organs and
tissues.
When the embryo is about 38 days old, the fetus
period begins. This term is used until the newborn is ex-
pelled at parturition. During the fetus stage, continued
attachment takes place at the numerous caruncles lining
the uterus. These attachments provide transfer of
nutrients and waste materials for the developing fetus.
Parturition occurs approximately 280 days after fer-
tilization, figure 6.

Palpation
Either hand may be used in palpation. One hand may
grasp the cow's tail as a handle. The other hand should
be well lubricated and shaped into a wedge by bringing
the fingers together as closely as possible. The hand is
pushed through the anus into the rectum with one swift
thrust. As the hand enters the rectum, fold the fingers
into a modified fist, figure 5. By balling the hand into a
modified fist as it enters the rectum, the fecal material is
pushed aside and the rectum straightened. Folds in the
rectum do not straighten as easily if the fingers are held
in a pointed position. This also eliminates puncturing of
the rectal wall with the sharper pointed fingers.
However, puncturing is rare, as the rectum is thick-
walled and resistant.










r .


Figure 9. Position of hand in early pregnancy.


1006.4






Cleaning the cow's rectum of fecal material usually is
not necessary. However, in early stages of learning,
cleaning the rectum increases feel. Remove fecal
material of cattle on range since it is so dry.
Feeling through the rectal wall is similar to feeling
through i layer or two of thin rubber. Most cattle are
cooperative. Thus, it should be possible to feel the
paunch and pick-up the reproductive organs without
difficulty.
Usually, the longer the examination, the more
resistance encountered. Occasionally, a small amount of
bleeding occurs. This should not upset the palpator. An
indication of rectum damage is a sandpaper or gritty
feeling. In this case, the mucosa lining the rectum has
been rubbed off in the palpation process. It is best to
stop further palpation when this occurs.
A thrust of the arm to the elbow is usually much bet-
ter than trying to put the hand into the rectum and
gradually working forward. It is much easier to work
to the rear, since that is the direction the cow is
pushing the fecal matter and the inserted arm. In
palpating, assume the animals are pregnant. Therefore,
reach farther than wrist deep to pick up the uterus and
the calf within.
Certain landmarks are evident inside the cow. The
pelvis forms a bone cradle for the reproductive system,
figure 5. The nonpregnant tract usually is located near
the top of the pelvic cradle and felt easily with
downward pressure. As pregnancy advances, the uterus
and cervix move down and into the body cavity.
The cervix with its firm feel is also a good landmark,
figure 2. After the locating the cervix, the palpator can
move forward to the uterus to determine pregnancy.
The paunch, located directly forward and to the left,
may feel like the end of a football and be rather soft and
mushy. The feel depends on the amount of feed in the
paunch. The feedstuff when mashed slowly returns to
normal shape. It does not have the watery, soft feel of
the pregnant uterus.
The "open" reproductive tract normally lies on the
floor of the pelvis. The horns of the uterus are coiled on
the front edge of the pelvis or, in older cows, may hang
slightly into the abdominal cavity, figure 7. The entire
tract may be held in the hand at this stage. Slight
pressure by the middle finger will separate the horns of
the uterus, figure 8. The ovaries are located in the broad
ligament on each side.
30-day pregnancy. A palpator, with skill and practice,
can detect pregnancy as early as 30 days after breeding.
Palpation at this early stage should be accompanied by
good breeding herd records. The palpator through
these records knows the approximate breeding date of
the animal.
In the early stage of pregnancy, the uterus, filled with
a small amount of fluid, will feel slightly thinner. One
horn is enlarged a little more than the other. Presence of
the embryonic vesicle at this time is determined by runn-
ing the horn between the fingers in a milking action to
feel the vesicle pop through the fingers, figure 9.


The embryo is only about /2-inch long. However, the
vesicle surrounding it is approximately 3A-inch in
diameter and filled with fluid, such as a balloon filled
tightly with water. On the same side as the enlargement,
the palpator will find a corpus luteum on the ovary. The
uterus, in much the same location as a nonpregnant
uterus, has not been displaced because of size or weight
at this time. The outer embryonic vesicle, which is
rather thin with little fluid, may be 18 to 24 inches long.
By pinching the horn of the uterus carefully, the mem-
branes of this vesicle are felt as they slip between the
fingers.



0


Figure 10. 60-day pregnancy. Uterus hangs over pelvic
brim.


45-day pregnancy. Most palpators prefer bulls be
separated from cows at least 45 days before pregnancy
determination. At 45 days, one horn of the uterus con-
taining the fetus is somewhat enlarged and thinner wall-
ed and the corpus luteum is on the ovary of the same
side. The fetus at this stage is approximately 1 inch long.
The vesicle around it is somewhat egg-shaped and
measures approximately 1 to 1 V2 inches long. The outer
membrane, which contains considerable fluid, may be
felt through the uterine wall. Attachment of the mem-
branes to the uterus has just taken place at approximate-
ly 38 to 40 days. Therefore, avoid moving the fetus
about in the uterus. The caruncles on the uterus join
the cotyledons on the fetal membranes for nutrient ex-
change.
60-day pregnancy. The uterus has enlarged until one
horn is about the size of a banana, measuring 8 to 10 in-
ches long. Weight of the contents pulls the uterus into
the body cavity just over the pelvic brim, figure 10. The
fetus has grown rapidly and, at this stage, is about 2 V2
inches long. The embryonic vesicles are still prominent
and, at this stage, may be felt without feeling the fetus.
The uterine walls have thinned considerably. The best
method of feeling the fetus is to bobble it with your
hand so that by gently tapping the uterus the fetus sw-
ings as a pendulum and hits against the wall of the
uterus and vesicle. The cervix remains on top of the


1006.5





pelvic cradle with the uterine horns moving forward and
downward over the brim. The ovaries are still suspended
by the broad ligaments and in early stages will be rather
high in relation to the uterus. As before, a corpus
luteum should be on the ovary of the same side as the
developing fetus. The presence of the fetus eliminates a
need for'feeling other structures.
90-day pregnancy. The uterus will have enlarged con-
siderably by this time, filled with fluid and increased.
growth of the fetus, figure 11. The fetus now is about
6 /2 inches long and has displaced itself to the floor of
the abdominal cavity, indicating the uterus has stretched
considerably. The cervix may be pulled to the pelvic
brim so that the cervix, body and horns of the uterus are
in the abdominal cavity.
The ovaries are usually pulled down with the uterus to
much lower than normal and may be palpated to either
side of the uterus. In larger animals, this is a difficult
stage of pregnancy because of displacement and the
distance from the anus to the developing fetus.
Factors other than presence of the fetus itself may
have to be considered at this stage. Displacement of the
uterus, an indication of pregnancy, should be con-
sidered. Another indication of pregnancy is enlargement
of the uterine artery with its characteristic "whirring"
pulsation. This artery passes in the forward fold of the
broad ligament supporting the uterus. At 3 months, it is
approximately 1/8 to 3/16 inch in diameter. The pulse
of the heart beat is felt easily as blood is carried into the
uterus to nourish the developing fetus.
Do not confuse the uterine artery with the femoral
artery lying on the inside of the thigh which supplies the
hind legs. The femoral artery is lying in the muscle but
may be palpated. Remember that the uterine artery is in
the broad ligament and may be moved 4 to 6 inches,
whereas the femoral may not. Another pregnancy in-
dication is presence of a corpus luteum on one of the
ovaries, although this corpus luteum may appear here


even in a normal cycle. The best indication of pregnancy
in absence of the fetus is the presence of cotyledons.
Cotyledons in a 3-month pregnancy should be flattened
and egg-shape and measure % to 1-inch across.
Although rather soft to the touch, they are firmer than
the thin-walled uterus. The membranes still are filled
tightly with fluid, figure 12.
120-day pregnancy. At this stage, the fetus is displac-
ed similarly to the 90-day fetus. However, it has enlarg-
ed to approximately 10 to 12 inches long. The head is
about the size of a lemon. Often the head of the
developing fetus is picked up before any other part.
The enlarged fetus fills a greater portion of the ab-
dominal cavity and is easier to feel than the 3-month
fetus, figure 13. All other characteristics have changed
some. Presence of the cotyledons is more noticeable,
since they have developed to approximately 1 V2 inches
in length. The pulsating uterine artery may be palpated,
as well as the corpus luteum and displacement of the en-
tire reproductive tract.
Over 5-month pregnancy. The main change until par-
turition will be in size, figure 14, as the fetus enlarges
rapidly utilizing more of the abdominal cavity. Table 1
summarizes outstanding identifying characteristics.


Other Factors
The paunch.As one reaches into the rectum, feeling
directly forward and to the left, the dorsal posterior sac
of the paunch may be palpated. This paunch in an
animal on good pasture or on full feed will be rather
firm and plastic to the touch. By mashing the paunch
you notice an indentation which gradually smooths
back over indicating that the paunch is full of feedstuff.
This dorsal posterior sac may feel much like the end of a
football, coming to somewhat of a point. This may be
misinterpreted under careless examination as a large
uterus in latter stages of pregnancy.


(Continued on page 9)


1006.6









/


Figure 11. Position of 90-day fetus. The fetus is now
about 6V2 inches long and has displaced itself to the
floor of the abdominal cavity.


Figure 12. 79-day fetus, with surrounding membranes
filled tightly with fluid. Grid scale V inch.


1006.7


- 4,W


III















TABLE 1. FETAL SIZE AND CHARACTERISTICS USED IN DETERMINING PREGNANCY

Fetal Size
Days of Length
Gestation Weight Inches Identifying Characteristics

30 1/100 2/5 One uterine horn slightly enlarged and thin; embryonic vesicle size of large marble. Uterus in ap-
oz. proximate position of nonpregnant uterus. Fetal membranes may be slipped between fingers from
30 to 90 days.

45 1/8- 1-1 4 Uterine horn somewhat enlarged, thinner walled and prominent. Embryonic vesicle size of hen's
14 oz. egg.

60 4 V2 2 '/ Uterine horn size of banana; fluid filled and pulled over pelvic brim into body cavity. Fetus size of
oz. mouse.

90 3-6 oz. 5-6 Both uterine horns swollen (3 to 3 V in diameter) and pulled deeply into body cavity (difficult to
palpate). Fetus is size of rat. Uterine artery 1/8 to 3/16" in diameter. Cotyledons %3 to 1" across.

120 1-2 lb. 10-12 Similar to 90-day but fetus more easily palpated. Fetus is size of small cat with head the size of a
lemon. Uterine artery 4" in diameter. Cotyledons more noticeable and 1 V2 inches in length.
Horns are 4 to 6" in diameter.

150 4-6 lb. 12-16 Difficult to palpate fetus. Uterine horns are deep in body cavity with fetus size of large cat-horns
6-8" in diameter. Uterine artery -3/8 in diameter. Cotyledons 2 to 2'i" in diameter.

180 10-16 20-24 Horns with fetus still out of reach. Fetus size of small dog. Uterine artery 3/8- V" in diameter.
lb. Cotyledons more enlarged. From sixth month until calving a movement of fetus may be elicited by
grasping the feet, legs or nose.

210 20-30 24-32 From 7 months until parturition fetus may be felt. Age is largely determined by increase in fetal
lb. size. The uterine artery continues to increase in size-210 days, V in diameter, 240 days-
240 40-60 28-36 V2 to 5/8" in diameter; 270 days, V2 to 34" in diameter.
lb.
270 60-100 28-38
lb.


1006.8





Figure 13. 4-month pregnancy. Tract lies on floor of ab-
dominal cavity. Palpation of uterine artery.


Figure 14. 5-month pregnancy. Enlarged calf now fills
abdominal cavity.


Cotyledons. Cotyledons may be interpreted as ovaries
or vice versa. Cotyledons do not have the solid feel of an
ovary but are rather soft. The best comparison is to that
of dried apricots soaked in water. The ovaries are more
rounded and egg-shaped with a firm feel. Only two are
present.
Pyometra. In this condition, the uterus is filled with
white blood cells attempting to clear up disease
organisms. The uterus may be fluid to the touch or may
be somewhat solidified, feeling rather plastic. This stage
may be confused, with early pregnancy stages if the
uterus is in a fluid condition and only partly filled. In
the latter stages of pyometra, the uterus becomes rather
firm.
Large uteri. In older cows that have had many calves,
the uterus may not return to its normal size as in a
younger cow. The enlarged uterus may feel as if dis-
placed over the brim of the pelvis as in a 3 to 4-month
pregnancy. Careful manipulation of the uterus shows
no fluid and no cotyledons developing in the open cow.
Relaxation of the broad ligament tends to cause a
similar condition.
Bladder. The urinary bladder may be interpreted as
pregnancy in the 60 to 75-day stages. At this time, the
full bladder feels similar to the uterus filled with fluid.
Careful tracing should indicate a bladder, where there is


only one body, or a pregnant horn of the uterus, where
both horns can be palpated and traced back to the cer-
vix.
Enlarged cervix. In some Brahman and Brahman
crossbred cattle, an enlarged cervix is found that is firm
and has the feel of a developing fetus in the latter stages.
Tracing the reproductive tract distinguishes between the
two.
Breed differences. Brahman, Brahman crossbred,
Santa Gertrudis, Charolais, Holstein and Brown Swiss
cattle, becuase of their increased size, are slightly more
difficult to palpate in certain stages of pregnancy than
the smaller European breeds.
In 3 to 4-month stages, the uterus has dropped so
deeply into the body cavity it is almost impossible to
palpate. In such instances, pass the hand under the cer-
vix and lift the uterus to feel the fetus itself. By lifting
the uterus and quickly moving the hand down into the
body cavity, the presence of the fetus is felt by bobbing
the fluid and the fetus through the wall of the uterus.
Brahman and Charolais breeds appear to have more
tissue inside than smaller breeds. More folds of the
momentum seem to cover the intestines, making it slightly
more difficult to pick up the uterus.
Charolais cattle seem to have less flexibility in the rec-
tum. It is commonly harder to feel deep in the body


1006.9


~L~m






cavity in these cattle, and lateral movement is somewhat
restricted.
The uteri of heifers of Brahman breeding vary con-
siderably. It is not uncommon to find 1,000-pound
heifers with uteri measuring only 4 to 6 inches in length,
as compared to a normal uterus which would be 10 to 12
inches.
Highly finished cattle for show or on lush pastures
may be filled with fat which interferes with movement
and feel. These cattle are very difficult to palpate.
Repalpate at a later date in case of doubt.

Recommendations
Practice! Experience is the key to palpation. In many
instances the ranch manager should not be the one to


Precautions

There are potential problems associated with
pregnancy determination by unskilled or poorly
trained personnel. The major potential problem is
abortion induced by rough handling or manipula-
tion during the early stages of pregnancy (30-50
days following breeding). The potential economic
loss associated with false determination should dic-
tate that the palpators used by ranchers need to be
well trained and concerned about the accuracy of
their diagnosis. Practicing veterinarians have re-
ceived adequate training and those doing regular


palpate but should supervise the operation and critically
observe the cows. Unhealthy, unsound and undesirable
types should be eliminated as well as open cows.
Shorten the calving interval by reducing the time dur-
ing the breeding season when the bulls are with the
cows. Cows that settle first are those most adapted to
reproduction. Wait approximately 45 days after the
bulls are removed to palpate. Most cows should con-
ceive at the beginning of the season, and only a few will
be short-tern pregnancies.
Cull as critically as feasible. If every open, unsound
cow can be removed, cull immediately.
Remember, palpation is an art and a skill. It pays
dividends to the person who uses it wisely.


palpations and fertility work in cattle are qualified
to give accurate and safe pregnancy determination.
In addition to pregnancy checks, the veterinarian
can also review your herd health program while on
the ranch.
Florida cattlemen generally pregnancy test the
cow herd at or shortly after weaning. For herds on
a limited, defined breeding season, this will be
more than 50 days after the bulls have been re-
moved, thus, the danger of abortion from manipu-
lation is reduced but accurate diagnosis made
somewhat difficult because of the advanced stages
of gestation.


COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
Cooperative Extension Service, IFAS, University of Florida
and United States Department of Agriculture, Cooperating
K. R. Tefertiller, Director


1006.10




















Crossbreeding of Beef Cattle
James C. Collins, Mississippi State University
James M. Moss, University of Arkansas


Research and commercial production has shown that
crossbreeding of beef cattle is an effective method of
improving beef production efficiency.
Within recent years, there has been a significant in-
crease in the acceptance and use of crossbreeding in the
cattle industry. Many commercial producers now cross
either English x English, English x Brahman, exotic x
English, exotic x Brahman, or beef X dairy breeds in
their breeding program.
In order to obtain maximum benefits from
crossbreeding, a cattle producer should completely
understand the advantages, disadvantages and limita-
tions of crossbreeding and crossbreeding systems.

What is Crossbreeding?
Crossbreeding is a planned mating of straightbred
cattle of different breeds or crossbred cattle with
straightbred or crossbred cattle of different breed com-
position. Therefore, it is the mating of cattle that are
genetically different. High grades may be used but the
indiscriminate mixing of various breeds is not
crossbreeding and will not produce desired results. The
"mongrel" animal is not a crossbred as such.

Why Crossbreed?
There are two reasons for undertaking a
crossbreeding program:
1. To combine the desirable characteristics of two or
more breeds to:
a. form a new breed or type with greater adap-
tability to a given environment or market
condition that will eventually be mated as a
closed population, and
b. produce market animals superior to either
parent breed in a continued crossing pro-
gram. With two distinctly different popula-
tions (breeds), neither may have all the
f) desired characteristics or be specifically
suited for a particular environment or pro-
gram. Crossbreeding allows for the infusion


of the desirable attributes from two or more
breeds into one population.
2. take advantage of heterosis or hybrid vigor for the
increase in production which is usually exhibited
by crossbred animals.

What is Heterosis or Hybrid Vigor?
Heterosis is the increase in average performance of
crossbred offspring over the average performance of
their straightbred parents for specific traits.

Percent Heterosis = Crossbred Average Parental Average X 100
Parental Average

The following example demonstrates this principle:
A straightbred cow herd of Breed "A", which has
been producing calves with a 400-pound weaning weight
is mated to bulls of Breed "B" from a herd which has
been producing calves with a 500-pound weaning
weight. The crossbred calves from these matings
average 475 pounds at weaning.
Hybrid vigor for weaning weight is calculated as:
475 (400 4500)
2
Percent Hybrid Vigor = X 100= 5.5 percent increase
of Weaning Weight 450

Which Traits Can Be Improved By Crossbreeding?
There is no doubt that crossbreeding of cattle will
result in the expression of heterosis for many traits.
However, the percent heterosis exhibited varies from
trait to trait.
In general, traits exhibited early in life and reproduc-
tive characteristics can be most improved by use of
crossbreeding (Table 1).
Generally, only those carcass traits which are related
to weight are improved by crossbreeding. Carcass grade
and tenderness generally do not show improvement due
to heterosis.
The greatest advantage from crossbreeding comes
from using crossbred females who exhibit heterosis for


1007.1






Table 1. Average Heritability, Expected Heterosis and
Best Method of Improvement for Various Traits

Type of Best Method
Trait Heritability Heterosis of Improvement

Reproduction Low High Crossbreeding
Growth Rate Moderate Moderate Crossbreeding
& Selection
Carcass High Low Selection

fertility and maternal performance (Table 2). The per-
cent of heterosis obtained will vary, depending upon the
genetic difference between the breeds used. For example,
heterosis values will be less for English crosses than for
Brahman x English crosses.

Table 2. Estimated Heterosis of Various Traits

Type of Cross Trait Heterosis

Singlecross calves: Calves born 1-2
Calf livability 2-5
% calf crop 3-6
Weaning weight 3-7
Feedlot gain 2-6
Crossbred dam: Calves born 4-6
Calf livability 2-6
% calf crop 4-8
Weaning weight 4-10

The heterotic effects on calves born, calf livability
and calf weaning weights are accumulative. The bar
graph illustrates the increase in pounds of calf weaned
per cow exposed in the breeding herd. An increase of
8-10 percent can be expected by producing crossbred
calves from straightbred cows and a 20-25 percent in-
crease by using crossbred cows mated to a bull of a third
breed.
While heterosis increases performance, breed com-
plementarity provides the opportunity to match strong
and weak points of two breeds, resulting in a calf
superior to either parent in overall merit.
For example, you might use a bull from a breed noted
for rapid growth from birth to weaning and high carcass
cutability and cows from a breed noted for fertility,
mothering ability and carcass quality. The final product
would be more calves weaned with greater total value.
Calf color is also important from a marketing stand-
point. Color indicates breed, and breed indicates perfor-
mance. By matching breeds, you can achieve acceptable
market color and still have desirable performance.
Breeders must avoid producing undesirable crosses
for their area, both from a production and market
standpoint.

What Breeds Should be Used for Crossing?
Knowledge of differences between breeds is impor-
tant in choosing breeds to use in a crossbreeding pro-
gram. Breeds should be selected to:


PERCENT
22


10 -


STRAIGHTBRED X-BRED X-BRED
CALVES CALVES CALVES
STRAIGHTBRED STRAIGHT- X-BRED
cows cows cows
Cumulative hetrois effeds for pounds of calf
weaned per cow exposed.
1. fit objectives and environment.
2. complement one another.
3. meet market demands.
4. satisfy personal preferences.

Most producers are limited to the cow herd they now
have. Therefore, the greatest decision will be in the
selection of the breed of bull. In selecting the cow
breeder breeds, particular attention should be given to
the following characteristics:
1. fertility.
2. economical maintenance.
3. longevity.
4. calving ease.
5. milking ability.
6. good disposition.
7. availability.

Characteristics that should be emphasized in selecting
a bull breed are:
1. fertility.
2. growth rate.
3. carcass quality and cutability.
4. calving ease.
5. availability.

No single breed or combination of breeds is best
suited in these traits for all areas and production and
marketing systems. Breeds must be selected and com-
bined to best fit the environment, management and
market of each individual producer.
1007.2


20
18





How Important are Genetically Superior Bulls?
The effective utilization of heterosis in practice
depends on using for breeding stock those animals that
are superior in their own performance in the traits that
are medium to high in heritability. Since most produc-
tion traits are moderately to highly heritable, purebred
bulls above average for those traits deemed important;
i.e., weaning weight, yearling weight, etc., should be us-
ed. It is generally accepted that 75-80 percent of the
genetic improvement in a beef herd is' from the sire side.
If a cattleman chooses to use bulls of lower quality and
performance than he presently uses in a straightbred
program, then the potential which has been identified
by research and practice cannot be expected in a
crossbred program.

Crossbreeding Systems
To properly use crossbreeding, a producer must plan
his operation in advance and consider his cow herd size,
potential herd size, facilities, available capital, potential
market, level of management, etc., and then decide
which system of crossbreeding and which breeds are
best suited for his operation. The following are ex-
amples of systems which may be used.

Criss-Cross or Two-Breed Rotation
This is the simplest crossbreeding system (Figure 1). A
criss-cross is a two-breed rotation or systematic
backcross involving only two breeds and two pastures
(Table 3). The present herd of straightbred cows may be
used as the base (Herd A). They are bred to a bull of a
different breed selected to complement the cow herd
breed. The crossbred or F, heifers are saved as
replacements for Herd B and bred to a bull of the same
breed as the original cow herd. The straightbred cows of
Herd A are gradually replaced by heifers produced in
Herd B.

Female
Replacements


Table 3. Characteristics of
Various Crossbreeding Systems

Mating System Minimum Breeding Heterozy- Heterozy-
System Herd Size Pastures* gosity (Calf) gosity (Cow)
Criss-cross 50 2 67 67
Rotational 75 3 86 86
3 Breed Any size 1** 100** 100**
Terminal 3*** 75*** 50***
2 Breed 150 3 100 67
Rotational
with Ter-
minal Sire

*Assumes natural mating
**Only if FI females are purchased ed
***Includes all animals in the system stem

With the use of artificial insemination, the number of
cows can be less than two bull units and only one
breeding pasture would be required. In place of a rota-
tion, a producer with only one bull unit of cows may use
bulls of Breed B for 5 to 6 years, then change back to
bulls of Breed A for the next 5 to 6 years. The bull must
be replaced every 2 years to prevent sire-daughter
matings. By changing sire breeds every 4 years, breeding
replacement heifers to calve at two years of age and cull-
ing about 12 percent of the older cows each year, the
highest concentration of one breed in any group of
calves would be 75 percent as a result of a single
backcross.

Rotational
This system requires three or more breeds of bulls
with crossbred heifers saved from each sire breed
(Figure 2). In this system, three herds or breeding
groups are maintained (Table 3).
The rotation starts by breeding the present cow herd
(Herd A) to a bull of a different breed. Females produc-
ed in this herd are used as replacements for Herd B and


Female


Female
Replacements

Figure 1. Crisscross or two-breed rotation.

The advantages are that this system: (a) can be used
by small producers; (b) is simple; (c) produces female
replacements for the herd; and (d) utilizes crossbred
dams.
Disadvantages are that: (a) only 67 percent of poten-
tial hybrid vigor is achieved (Table 3); and (b) with
natural service, two breeding pastures are required.
1007.3


Replacements

r7 (


Figure 2. Rotational crossbreeding system.






bred to a bull of a second breed. Crossbred heifers from
Herd B are used as replacements for Herd C. These
heifers are then bred to a bull of a third breed (the same
breed as the original cow herd). After this, rotation is
continued with the same breeds of bulls.
The main advantage of the three-breed rotation
systems are that: (a) it maintains an 86 percent degree of
hybrid vigor (Table 3); (b) female replacements are pro-
duced in the herds; and (c) crossbred dams are utilized.
Disadvantages include the need for: (a) large number
of cows and cow herds; (b) three or more breeding
pastures; and, (c) greater management skills.
Rotational crossbreeding may involve four, five or
more breeds. With more breeds in a planned rotation, a
slight increase in heterotic response can be obtained, but
management becomes more difficult.

Terminal Cross
The terminal cross is not a self-perpetuating system
like the criss-cross or rotational systems. It requires the
input of straightbred females into the system at some
point. Figure 3 illustrates one method that can be used.


\ 9
Offspring marketed
Pounds of oalioow
Increased about 192I


Figure 3. Terminal Cross

Herd A is maintained as straightbred cattle with
replacement heifers being produced within the herd.
Replacement heifers for Herd B are also produced by
Herd A. Herd B females are mated to a bull of a second
breed (B) to produce crossbred heifers (BXA). These
crossbred females are then mated to a terminal sire (C)
and all calves are marketed.
Advantages of this system are: (a) maximum hybrid
vigor in the FI female and terminal cross calf; and (b)
selection of breeds that complement each other.
Disadvantages are that: (a) a high percentage of
straightbreds must be maintained to provide replace-
ment heifers; (b) a large operation would be required for
this system; (c) approximately 50 percent of the brood
cows would be straightbred; and (d) 20-25 percent of
market calves would be straightbred.
This system may be modified so as to involve more
than one producer. For example, one producer might


produce the straightbreds with another producer com-
pleting the first and terminal cross. An individual pro-
ducer may complete only the terminal cross by purchas-
ing FI females and mating them to a bull of a third
breed. However, these crossbred heifers may be hard to
locate and high in price.

Combination Criss-Cross and Terminal Cross
Many modifications of the three systems mentioned
previously are possible. For example, Figure 4 illustrates
a program in which a criss-cross and terminal cross are
combined. In this program, Herds A and B would be us-
Female Replacements


&V am-R


Figure 4. Combination crisscross-terminal system.
ed in a criss-cross as illustrated in Figure 1. Replacement
heifers would be produced from these two herds. Only
the superior cows would be retained in these two herds.
Older and poorer producing cows would be taken from
the Herds A and B and placed in Herd C. These would
then be bred to a bull of a third breed for a terminal
cross and all calves from Herd C would be marketed. In
this manner, a producer would take advantage of the
terminal cross to maximize hybrid vigor without having
to purchase female replacements from an outside
source.
If we assume that we obtain 66 percent of the max-
imum heterotic response in the criss-cross, 100 percent
in the terminal cross and have half of the total cows in
Herd C, we would expect this total system to realize ap-
proximately 83 percent of the potential hybrid vigor.
This does not appear to be as useful as the three-breed
rotational in terms of total response. However, consider
that in this system, the cows can be selected for maternal
traits and the third breed utilized in the terminal cross
could be more specialized for growth and carcass
characteristics without regard to maternal traits, which
are important in the three-breed rotation. In other
words, complementarity can be used to a much greater


1007.4






degree and, when combined with hybrid vigor, should
provide a greater total response.
This system also provides some flexibility in altering
herd size since Herd C can be reduced or enlarged
without changing the basic crossing system.

What are the Requirements for a Successful
Crossbreeding Program?
To obtain maximum results from a crossbreeding
program, a producer must have:
1. A planned breeding program. Desired results from
a crossbreeding program are due to maintaining a
high level of heterosis and combining the desired
traits of two or more breeds in order to obtain
maximum economic value in the offspring. Proper
breed selection and mating combinations are
essential.
2. Good management. Crossbreeding is not-a cure-
all that will immediately eliminate poor produc-
tion in a herd. Recommended practices such as a
limited breeding season, pregnancy testing, culling
open and poor producing cows, adequate nutri-
tion, disease control, etc., are just as important in


a crossbreeding program as in a straightbreeding
program.
3. Performance tested, genetically superior bulls.
Superior parents in crossbreeding produce
superior offspring plus the advantage of hybrid
vigor. Mediocre parents in crossbreeding produce
mediocre offspring plus the advantages of hybrid
vigor. In a crossbreeding program, the continued
use of superior bulls provides the major source of
genetic improvement for the herd.

Will Crossbreeding Work for Every Producer?
Research and result demonstrations have shown that
it will work for those who make it work. The important
aspect to consider is the understanding of the uses,
merits and limitations of a crossbreeding program as it
may affect an individual beef producing enterprise.
Many producers will find crossbreeding advantageous
in their beef production program. Some will not find
crossbreeding advantageous due to their management,
physical facilities and/or marketing system. It is a
management tool that when properly planned and con-
ducted can increase beef productivity per cow by
10-25%.


COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
Cooperative Extension Service, IFAS, University of Florida
and United States Department of Agriculture, Cooperating
K. R. Tefertiller, Director


1007.5





Animal Science Fact Sheet


Heat Detection and

Artificial Insemination in Cattle

R. S. Sand*


Florida Cooperative Extension Service / Institute of Food and Agricultural Sciences / University of Florida / j.T.Woeste, Dean


Artificial insemination of beef cattle is becoming more
popular each year. The recent boom in beef Al has been
partly caused by the increased interest in the European
beef breeds. The difficulty in importing breeding stock
along with less restrictive importation requirements for
semen has made AI with semen from bulls of these breeds a
good way to incorporate them in a beef cattle breeding
program.






Heat Detection
Successful use of artificial insemination depends par-
tially on the skill of the inseminator in handling semen
and inseminating the cow, but the key to success lies in
detecting the cow in heat. People who are around their
cattle several times a day such as dairy men are more
likely to see the signs of heat. However, anyone who is
aware of what to look for and is observant can usually
spot those cows which are in heat. Some of the usual
signs are restlessness, bawling, riding other cows, standing
while being ridden, and mucous discharge from the vulva.
All, some or none of these signs may be observed in a given
animal. Since cows are so variable in their expression of
heat, several aids have been developed to help detect heat.
The most common method is close observation several
times a day by experienced personnel. Many successful
operators quietly ride horseback through the beef cow herd
two or three times a day looking for animals displaying signs
of heat. Frequently one of the telltale signs is mud and/or
roughed up hair on the back where other animals have been
attempting to mount. Sometimes the tail head will become
conspicuously elevated. The animal may leave the herd and
start walking the fence or just stand around bawling. Early
in the morning and late in the evening are usually the pre-
ferred times when the herd is checked only twice a day.


Heat Detection Aids

Aids that can be used to detect heat are: a vassectomized
bull, a bull with penile system altered to prevent copulation
(to reduce the spread of general disease), or a steer
pretreated with male hormone and equipped with a mark-
ing device such as a painted brisket (grease and lampblack
mixture) or marking harness. Some operators have had
limited success with intact bulls, aproned so they couldn't
serve the cow, turned out for short periods two or three
times a day.
Mechanical devices are on the market to aid in identify-
ing when animals are in heat. The most popular product of
this type consists of a clear plastic device with an adhesive
backing which is placed on the back of the animal
between the hip bones and the tail head. After weight has
been exerted on the patch for.a short time it turns bright
red. The necessary weight is provided by another cow
mounting and riding.
Even with the use of these aids a successful Al program
requires frequent checks of the cow herd together with an
easy system of positive identification so that the right cows
are bred at the proper time. Heat detection aids just help in
identifying which animals are in heat and will not replace
careful observation by the herdsman.

Insemination Timing

The proper time for breeding in relation to heat has been
rather extensively observed and is generally anytime during
the period from when a cow is observed in a standing heat
up to 12 hours after the end of the standing heat. Since the
fertile period in the cow is relatively short (approximately
30 hours), it is very important that the cow be detected as
soon as she comes in heat in order to have time in which to
get her inseminated with a maximum opportunity for
conception. For highest fertility cows should be inseminated
during the last half of standing heat or within six hours
after the end of standing heat.


*Associate Professor, Extension Beef Specialist, Animal Science Department, Institute of Food and Agricultural Sciences, University of Florida,
Gainesville.


AS 4





,Artificial Insemination

Artificial insemination, like many other tasks, is handled
Most successfully by developing a step by step routine so all
essential elements of the procedure are completed. The
following outline is presented as a guide for development of.
a procedure to fit your circumstances. Be sure to practice
careful sanitation to avoid spreading disease.

S-E'QEUIPMENT REQUIRED:
4. .. _a,
1. Shoulder length glove and lubricant
2. Disposable inseminating tubes
3. Disposable towels
4. Head squeeze or breeding shute
5. Syringe (2cc) or bulb
6. Thaw box (insulated container with lid for ice and
water)


Insemination Technique

-As you arrive at the breeding shed rororral, transfer the
'isme to be used from 'the liquid nitrogen storage tank to
an ice water thaw box for slow thawing. After securing the
cow, remove the semen vial from the ice water bath. Make
sure a'llsemeh is completely thawed but.

"1. Score and car fuiiy"renmiove the top bf the se meni vial.
2. Draw the semen into the inseminating tube being sure
v to -removeb all vailablb- effi-i. HoldlThe filled inseminat-
Sing tube so it is out of bright sunlight : r cover t with a
paper towel. ':
3:; Ihsert your gloved handing' the rectum of the cow and
S fremove'the fecal material.,
'~4. Wipe offthe vulva wiith a paper towel.
5. Gietly pick tip the cervix with the haid in the rectum.
Remember the tissues of the rectal iall are fragile so
h-fwialidle carefuFlly.
S6. Insert the inseminating rod in the vagina and guide it to
the cervix. Gently insert if through the cervical rings by
''manipulation of the cervix. Hold a finger over the end of
: 'he cervix to feel when the tip of the inseminating tube
enters the uterus if this is the first inseriination.
7. On second service or if there is any possibility the
animal is pregnant, deposit thie: semen in :the middle
of the cervix.
8. Hold the bulb or syringe depressed so that orine of the
'r"ex?: Olledi semeri is drawn back up into the inseminating
Stube while withdrawing it.
A. always pro6prly dispose 6f all materials after recording
:'ithe' irif-rlmation on the semen vial, Use the disposable
:- irseliinating tube only once to avoid any possibility of
spreddiig'veneral disease between cows.
1O0 Whn' using semen*frozen in plastic straws, follow the,
manufacturer's' or distributor's instructions 'for thawing
arid handling the semen. : : : i .' :
]i


'Genital Organs the Cow
t' .fl 'SJ "I


. L-.1*..-


This fact sheet was printed at a cost of $46.20, or 3.1 cents per copy, to provide information to cattle owners about
artificial insemination. 2 1.5M -80

COOPERATIVE EXTENSION SERVICE, UNIVERSITY OF FLORIDA, INSTITUTE OF FOOD AND AGRICULTURAL
SCIENCES, K. R. Tefertlller, director, In cooperation with the United States Department of Agriculture, publishes thit Infor-
mation to further the purpose of the May 8 and June 30, 1914 Actsof Congress; and is authorized to provide research, educa-
tlonal information and other services only to Individuals and institutions that function without regard to race, color, sex or
national origin. Single copies of Extension publications (excluding 4-H and Youth publications) are available free to Florida
residents from County Extension Offices. Information on bulk rates or copies for out-of-state purchasers is available from a
C. M. Hinton, Publications Distribution Center, IFAS Building 664, University of Florida, Galnesville, Florida 32611. Before publicizing this
publication, editors should contact this address to determine availability.


0


C)


:





Animal Science Fact Sheet


Florida Production Testing Program for Beef Cattle

R. S. Sand* a A S

Florida Cooperative Extension Service/Institute of Food and Agricultural Sciences/University of Florida/J. T. Woeste, Dean


Introduction

Production testing in Florida is a joint effort
between the Florida Cooperative Extension Ser-
vice and the Florida Beef Cattle Improvement
Association. The Florida Beef Cattle Improve-
ment Association (FBCIA) is a non-profit orga-
nization composed of participating cattlemen de-
voted to improving beef production primarily
through keeping and using objective records. Dif-
ferences among animals in traits that affect the
economic value (selling price) are, to a large ex-
tent inherited differences. Thus, regular measure-
ment, recording and use of the records in selection
will increase the rate of genetic improvement.

The rate of improvement will depend on (1)
the amount of the observed differences between
animals due to heredity heritabilityy of a trait or
traits); (2) the difference between the average of
the selected group and the average of the herd
from which they were selected (selection differen-
tial) ; (3) the relationship among the traits being
selected for (genetic correlations); and (4) the
age of the parents when the offspring is born
(generation interval).


All comparisons and selections should be made
within a group or herd that has been produced in


a similar environment. Thus, records of perfor-
mance should not generally be used to make com-
parisons between herds or ranches where large
differences may exist due to location, nutrition,
management or health. The use of ratios is the
most accurate method of making between herd or
ranch comparisons. However, it should be kept in
mind that environmental adaptation may be re-
sponsible for individual performance and that
without that environment the animal may not per-
form as well or it might perform better.
The Beef Impir1..tm.-l.it Federation gives the fol-
lowing as the principal features of effective per-
formance record programs:
1. All animals of a given sex and age are given
equal opportunity through uniform feeding
and management.
2. Systematic written records are kept of im-
portant traits of economic value on all
animals.
3. Records are adjusted for known sources of
variation, such as age of dam, age of calf and
sex.
4. Records are used in selecting replacements
(bull and heifers) and in culling poor pro-
ducers.
5. Management practices and nutritional pro-
grams practiced are compatible with those
where progeny of the herd are expected to
perform and are uniform for the entire'herd.


*Associate Professor, Extension Beef Specialist, Animal Science Department, IFAS, University of Florida, Gainesville.


AS 5







Operating Sequence
The FBCIA program is designed so that infor-
mation is only recorded once to keep the paper
work of the cattleman to a minimum. The use of
preprinted forms and minimal required informa-
tion contributes to the ease and simplicity of the
program. In order to keep and use accurate
records, each animal in the herd must be perma-
nently identified as to year weaned and individual
herd number. This permanent identification on
the animal can be by fire brand, freeze brand,
horn brand, tattoo, neck chain or ear tag.



Birth List
The operating sequence of the program starts
with the birth list which is a list of all dams
(cows) in the herd listed by their identification
number consisting of year weaned and herd num-
ber. As each cow calves, the number ai-jTl to
the calf (composed of year weaned, herd number
and brand), its sire (optional), sex and birthdate
are entered in the .tpi:'p-rlto. spaces. If actual
birth v. eight' are measured they should be entered
in the appropriate column, otherwise the ci..nput. i"
uses a standard birth weight of 70 pounds. As
soon as calving is complete the birth list is sent in
after coding open cows (cows which do not calve)
with a 9 in the survival (S) column.



Wean List
When the completed birth list is received by the
FBCIA office, a wean list is prepared and sent to
the cattleman. The wean list is the same informa-
tion that was entered on the birth list i.e., calf
number, breed, sex, sire (optional), dam, birth-
date.and birth weight (if taken).
However, the wean list is sequenced on calf
number. The wean list is used to record the date,
weight and visual a'prai-al score (optional) when
the calves are weaned, and the weight of the cow
if you want l'.uii., of calf per 1i000= of cow cal-
culated. Open cows and cows that have lost calves
or died should be properly coded and included.
This list is sent back to the FBCIA office when
all calves have been weaned. A partial list of
calves weaned may be sent in if, as a result of a
long calving season, their wean data is needed
before the rest of the calves are scheduled to be
weaned.


Wean Data
The wean data that is returned to the producer
consists of three parts: (1) the calf list sequenced
by sex and calf number; (2) sire list sequenced
by sire number (if known), sex, and calf number;
(3) sire (if known) averages.





Cow Production Summary
At the end of the third year on the program, the
producer receives a cow production summary.
This is a listing sequenced on cow number contain-
ing all of the information on file for each of his
cows, plus an average of their calves' weights
and other data. A birth list for the next year is
sent with each cow production summary. This
lij'jfly is the sequence and lpurp,-e of the finm-
used to record and evaluate weanling calves.





Requirements and Rules for Recording Data
One of the most frequent problems with new
herds is the use of alphabetic characters. The only
place on any of this program's forms where alpha-
betic characters can be used is the two columns
headed "Brand" following each Animal, Sire and
Dam number. In all other columns, numbers must
be used. This is because the computer systems and
programs used to process the data only recognize
numbers in most information.
Another frequent source of error is lack of
maintaining a constant dili!tifl'cati,,i of each ani-
mal. Any change (even the addition or removal
of a zero) in the number or brand or breed col-
umns changes the identification so that the com-
puter considers it as two different animals. Ex-
amples: 75 0048 07 is not the same as 75 0048 7
as far as the computer is concerned. Once an
identification number is assigned to an animal,
do not change it.
Breed and sex codes are in the code tables below.
Calf weight used to calculate the weight ratio is
adjusted for sex. Therefore, be sure to code the
sex of each calf. Breed codes are provided for use
of the breeder and do not enter into the computa-
tions. Breed of sire and breed of dam can be coded
for those breeds with a single digit code. The dou-
ble digit codes should be used to code breed of sire.







It is not necessary to have sire data. Most com-
mercial operations run multiple sire herds. Sire
information is useful management data but not
required for the program to function.
The two columns headed "S" and "R" are im-
portant sources of management information. "S"
stands for survival and the codes for this column
are in the table below. In averaging values for
weight ratio and index, the computer considers






Survival Codes
1 Survival to v ..i:in;r. raised on dam
2 Survival to weaning, not raised on dam
3 Stillborn, or calf died on delivery
4 Died before three days
5 Died after three days
6 Cow sold pregnant or had calf but not
paired, cow accounted for as pregnant but
not counted in calf survival, or incomplete
information
7 Pregnant cow died*
8 Aborted
9 Cow open




Reason for Death Codes**
0 No death
1 Calf born weak and failed to nurse
2 Calf abandoned by dam or dam had no
milk
3 Dystocia, difficult birth
4 Respiratory disease
5 Blackleg or related disease
6 Lightning
7 Accidental death
8 To be coded later
9 Unknown


only those animals with a survival of 1. Some of
the other codes are also used to figure prn _v.,.iv
and survival rate. "R" stands for reason for
death and the codes for this column are in the
table below. Zero or a blank is used under "R" for
all calves that do not die. It is not a requirement
to use the suggested "R" codes. You may substi-
tute your own if they will help your operation;
however, their meaning should be known.






Sex Codes


Bull
Steer
Heifer


Breed Codes
Angus
Brahman
Brangus
Charolais
Limousine
Hereford
Beefmaster
Simmental
Santa Gertrudis
Unspecified breeding
Galloway
Maine-Anjou
Chianina
Blonde d' Aquitaine
Hays Converter
Fleckvieh-Gelbvieh
Murray Grey
Beef-Dairy Cross
Beef Brown Swiss


**Examples or suggested codes


There are seven columns that are headed 1 2 3
4 5 6 7, or control, near the right side of the page.
These columns are provided for the rancher to
code breeding herds, pastures, color patterns, tem-
perament, creep feeding etc. Any information on
any calf you wish to record can be numerically
coded in these columns and becomes part of that
animal's permanent record.


*Prior to 1968 a code of 7 was used to indicate a
still birth (now included in 3) and there was no code
for a pregnant cow that died.













Below is an example of a birth list and how it
should be filled out. Please note the handwritten
entries.

ANIMAL SIRE DAM
R" .- ........ ... N' "--c N,:- D. A' .....U. o A- T FF. 1 ijijT cc CF I

S'r r-_ 5 ,, i Y Cf I,__. :i I1- IA e ,
SIRE 69 33 IJ7
1 71
,1qyl /5^ fc 13 / 1/ /,,z 7: io0: _3 j 2/I>/?j' -^_7_





9999 Publication Ranch 1975 Birth List





This is how the above birth list looks when it is
returned as a wean list. Note that it is now se-
quenced on calf number, not dam number. Note
the handwritten entries when calves were weaned.
Cow weight (optional) should be put in the last
column if interested in having calf weight per 100
pounds of cow calculated.









S __ ___-_ -,-, .,





9999 Publication Ranch 1975 Wean List


PAGE 1


PAGE 1








Wean Data
There are three listings included in the wean
data: (1) calf list sequenced on sex and calf num-
ber; (2) sire list sequenced on sire number, sex
and calf number; and (3) sire averages for all
calves.
The information printed on each calf includes
animal identification (year, number, brand, sex
and breed), sire identification if known (year,
number and brand), dam number (year, number,
brand and breed) birthdate, survival and reason,
actual weight and age in days at weaning, 205
day weight, 205 day weight adjusted for age of
dam (factors used are in Table 1), weight ratio,
score 1 (condition optional), score 2 (conforma-
tion optional), control, index and pounds of calf
per 100 pounds of cow (optional).
The formulas used to calculate the various ad-
justed or estimated values are as follows:

Weight Ratio =
Ind. 205 day wt. adj. for age of dam and sex 1
group avg. 205 day wt. adj. for age of dam and sex

Index =
100 + (wt. ratio 100) heritability of wean wt. x 100
+ (price ratio 100) heritability of grade


Fwean wt.-birth wt?*
205 day weight = 20.-, an wot. bh wt + birth wt.
age of calf (days)


*If actual birth weight is not given, a standard birth
weight of 70 pounds is used.


calf wt. 205 day wt. adj. for age of dam and sex x 1000
1000 cow weight

On the wean data printout, the calves are
grouped by sex and averages calculated for each
sex group in addition to the usual average for all
calves. The averages printed are: actual weight,
actual age in days, 205 day weight, 205 day weight
adjusted for age of dam, weight ratio (which will
always be 100), score 1, score 2 control and index
(which will always be 100).
Ratios are calculated by adding adjusted wean-
ing weight or index for all calves with 1 survival,
dividing by the number of calves, then taking this
average value and dividing it into each individual
calf's weight or index, then multiply by 100. This
value is printed as the weight ratio or index.
Also printed above each average line are the
letters NN, ND, N1, P, S and W. NN stands for
the number of records in the report, ND=number
of dams, N1=number of records with survival of
1, P= pregnancy rate, S survival rate and W
= wean rate (P% x S%).


P= NN N9 100
ND


( "survival of 9 )


SN1+ N2
S = x 100
NN (N6 + N9)


(1, 2, 6 and 9 refer to survival codes)


ANIMAL SIRE DAM BIRTH WEAN 2C5205 1 SCORE CGNTROlIK- hT/
YR. NC '; ..S .....* | , ... '. I C .T AGE hTAiPG TC 1 2 12 4 56 FC i __
75 1 0' 1 69 10112 69 233 Oa LiTC IC3 I 5C, 5 248S 4229t,4 s, I L CCC5. -CMC I

CALF AV F SE (-1 NN ND N1I P S I
S__ 1 1 00 100 100 505 248 429429 94 13 C 00 95 41
7! 42O 1 3 70 23YK ,71 303 20 1C1 1:iC In1C 1 E 241 4C242 7ocC 1o 0 0 .: 7 .
7 154 O' 3 69 lu i2 710 L 2 C 2 C2'7r iC 47 2 1 I 1 L -

EC LF A -F R -E =3 Ni D- N21 S-- -J .. .
___2 2 21 O 1 -C li:iJ ib8 23C 42737 11:i 1- JCo i.


75 72 0
T5 269 0

C~LF A


~A ALL -C

--I-9- -
-YT 4U
ggq-r~T


5; 72
5 70


VES '


SUr AT IK


II C 00CCOOC~
lj L 'CCCCOCC

13 0 i0l


113 475


li C 00 i O. L 4 7

RAGE 1


222ZL 70 206 0C1201j1275 1 395 239 34R 48 K
23YK 69 253 G002C3 175 I, 44u 182 4e5Y45 ItO
NN ND NI IF i

-------,.....----T--.....--- -----------
2 2 1. C 100 o ioo 418 2 12 41417 10(


i l l I __
R NN- |975 ED N4 P E9 ~S .
5 5 5 1C00 100 100 455 22' 423427 1 11

HAtNLt- 1'175 hEAN WEAN LATE (.9 IL 7. J--







For this information to be meaningful, all cows
exposed to bulls must be included on the wean
list and properly coded in the wean data. The
dead or sold cows are included on the cow produc-
tion summary; however, they will be deleted be-
fore the next birth list is prepared.


The second listing of the wean data is the sire
listing. The calves are listed by sire according to
sex and number (all the bull calves by one sire
are listed and averaged, then all the steers, fol-
lowed by the heifers). All calves by another sire
are similarly listed.


ANIMAL SIRE DAM BIRTH WEAN 2C5205 WT SCORE CONTROLIN- WT/I
__ NO .. N .. MCCEYR SR WT AGE hTAAD PT 1 2 123456FDEX IC00
7 1 0 0 1 69 10112 69 233 0 101C375 10 505 248 429429 94 13 C OGCOCCC 95 A41

SIRE A' FOR ;E 1i NN NO N1 P S W
6 101 "Z 1 0Ij 1C 100 100 505 248 429429 4 13 C 00 95 AI.?

7 154 O 0 3 69 10112 70 102 OO3102C275 10 475 218 451 51 IC3 13 C OCCOCC 14 425

SIRE Af IR -E:3 NN ND N P S W __
69 1011 1 1 100 100 100 475 218 451451 103 13 C 00 104 42:

75 42 7 1 3 70 23YK 71 303 0 11075 C 460 241 '40222 9 12 C( C@OG 5 4

SIRE A 'F P Ei=3 NN ND Nl P S
70 23 1 I 1 1, 100 100 100 460 241 4C2 22 9 12 C 00 '5 445

75 269 O 0 5170 23YK 69 253 00O 2031075 10 440 182 485485 120 14 C |OCCCOC123 576


II
SIE ___ ______ ______ _____________ coo 2


7 72 0 O 5 72 222ZL 70 208 012011275 10 395 39 348?48 E II G 000000 3 373

SIARE A IFR E 5 NN ND N P S W
72 222 LI I 1 100 C1 IC0 395 239 348?48 86 11 C 00 83 373

999 PU'BL ICT n RANCH 1975 -EAN -EAN LATE 09 0 o PAGE 2. -







The third listing is the sire averages. Each sire
is listed with an average for all calves (all sexes)
including reproductive data and all traits.


ANIMAL SIRE DAM BIRTH WEAN 2C5205 W1 SCORE CCNhRL I WT/
YR. NO o B.DREDo sE YR NO. : . | NO' M ,".. OCAYR SR WT AGE hTAAD rlT 1 2 12?456 DEX ICC';

SIRE A ALL SE ES NN D, N P 5 w
S6 101 AI


13 C


r- t--- -f I ~ t --E ~-- -I--


P s


{ES NN ND NX P S
1 1 I1 10Uo 10C


Ir-N ANCh 1975 TE WEAN C


k 450
100 450


444154 1C(


13 C


1 I + -4---t~ t-


W
ICO 395


239 348348 84 11 C


00'


f- 1. 1______


08 75


SIRE A


(ES


7i 23 I 2 2 00 100


OO 100 100 490 233


1C' 422



1 -4 511


d3 37,


SIRE A
7; 222


_EM


. fir


IATE 09


PAGE








Cow Production Summary
At the end of the third year, a cow production
summary for each herd is prepared which lists
each cow and all the information on each calf she
has had that has been performance tested. Also
printed is her lifetime average, including number
of records, number of years, number of records
with survival of 1, pregnancy rate, survival rate
and wean rate plus-the averages for weight, age,
adjusted weights, weight ratio, score, control,
index and wt/1000 (optional starting in 1976).


The cow production summary is sequenced on dam
(cow), year and number.



average wt/1000 total wt/1000
number N1 calves



Thus, unless this has been calculated each year of
the cow's productive life, the average will not be
accurate.


ANIMAL SIRE DAM BIRTH WEAN 205 205 WT SCORE IN- WT/
YR. NO. Io BRAND ; |. --, i I 4-.C UT 'L D FQl 1 2lVl i

71 174 10O 01 5 68 3 30 69 233 000103 06 71 10 554 279 426 447 122 12 0 131
72 393 0 0 01 1 68 3 30 69 233 001022 28 72 10 532 230 482 482 112 11 0 117
73 331 010 01 5 67 112 41 69 233 0010101 21 73 10 537 254 447 469 120 15 0 129
_7Z ou, o 9_ -, _b.I 69 3'j o01'01 i _'0 7 -. 10 1 5' 250 500 123 0129
75 1 00 01 1 69 48 86 69 233 0010j 1 03 75 10 505 248 429 429 94 13 0 095 418


DAM 6902!3 ,IVE A E = NN N NI P 1S W
5 5 5 100 1M0 100 544 252 457 470 114 13 0 120 084

71 192 0 0 02 1 68 3 30 69 253 000203 08 71 10 368 277 291 291 79 07 0 077

72 406 010 02 1 68 3 30 69 253 00 0203 29 72 10 443 265 359 376 96 09 0 095
73 564 010 02 5 67 112 41 69 253 000!02 28 73 10 240 230 222 222 55 06 0 049
74 604 010 02 1 69 48 86 69 253 0010201 29 74 10 508 247 434 455 107 14 0 110
75 269 0!0 02 5 69 48 86 69 253 00i0203 10 75 10 440 182 .b' 485 120 14 0 123 576


DAM 690:.5 LI E VE = NN ND NI IS W
5 5 5 1 0 l0o 100 400 240 358 366 91 10 0 115 115
S-1--
____ ___-4-_____________ __ ___


999 Pu$11icatiob Ranch


1975 Cbw IProductibn


Program Options Available
1. Cow herd list sequenced on most probable
producing average.
2. Pre-printed post wean list with or without
actual weaning weight and data.
3. Life time sire production summary.


For further information, contact your county
Extension agent or Dr. R. S. Sand, 313 Rolfs Hall,
Gainesville, Florida 32611.








































































This public document was promulgated at an annual cost of $260.95, or 17V/3 cents per copy to inform
Florida cattlemen about the Florida Production Testing Program for Beef Cattle. 2-1.5M-80




COOPERATIVE EXTENSION SERVICE, UNIVERSITY OF FLORIDA, INSTITUTE OF FOOD AND AGRICULTURAL
SCIENCES, K. R. Tefertller, director, in cooperation with the United States Department of Agriculture, publishes this infor-
mation to further the purpose of the May 8 and June 30, 1914 Acts of Congress; and is authorized to provide research, educa-
tional Information and other services only to individuals and institutions that function without regard to race, color, sex or
national origin. Single copies of Extension publications (excluding 4-H and Youth publications) are available free to Florida
residents from County Extension Offices. Information on bulk rates or copies for out-of-state purchasers is available from
C. M. Hinton, Publications Distribution Center, IFAS Building 664, University of Florida, Galnesvllle, Florida 32611. Before publicizing this
publication, editors should contact this address to determine availability.






























The purpose of this leaflet is to inform Florida beef cattle breeders of
the opportunity, value and procedure of evaluating their cattle for growth
after weaning. The Florida Beef Cattle Improvement Association offers this
program through the Florida Cooperative Extension Service.

Economic traits of beef cattle include those that contribute to production
efficiency as well as desirability of product. Growth rate is considered to be
one of the major traits of economic importance. Differences between growth
rates of animals are due to two major causes, genetic and environmental. Also,
the observed or measured growth rate of each animal is the result of its heredity
and the environment in which it is raised. It is well known that when cattle
are kept under similar or nearly equal conditions and their growth rates are
adjusted for known environmental differences, such as age of animal, age of dam
and sex, genetically superior animals for growth can be identified. Growth from
birth to weaning has been demonstrated to be highly influenced by the maternal
(milking) ability of dam. Post-weaning growth rates, particularly to 550 days
(18 mo.) of age, more accurately reflect the individuals inherited rate of growth.

With respect to growth after weaning, yearling weight at 365 days or long
yearling weights at 452 or 550 days are particularly important because of their
high heritability and high genetic association with efficiency of gain and
pounds of retail trimmed boneless beef produced.

Cattlemen who expect to feed their animals a ration which will allow
maximum growth can evaluate their animals on a 140 day test after weaning, or
at about 365 days of age, and identify genetically superior animals for growth.
Cattlemen who feed their animals on a ration which will not allow maximum
expression of growth and those who prefer to grow their animals on grass with
or without supplement should make evaluations at 550 days of age. This is
because it takes longer for animals to express their true genetic differences
for growth on a limited or high roughage diet.


ISand, Assistant Professor, Extension Livestock Specialist, University of Fla.
Department of Animal Science, Gainesville, Florida 32611
2Franke, Associate Professor, Animal Science, University of Florida, Gainesville,
Florida 32611


COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS. STATE OF FLORIDA. IFAI. UNIVERSITY
nr rln nr uA a nePIARTMENT OF AGRICULTURE. AND OQARDS OF COUNTY COMMIUIONERS. COOPERATING







-2-


DATA NEEDED Information necessary to evaluate post-weaning performance
includes animal identification, birth date, sex, date and weight of the animal
when the test started, date and weight of the animal at the end of the test and
a visual grade (optional). Sire of the animal is needed if sire summaries are
wanted.

COMPUTATIONS MADE When data are obtained from cattlemen, the information
is punched on computer cards, computations are made and the following is printed
out: Animal ID, sex, days on test, average daily gain, gain ratio, age at final
weight, weight at standard age (365 or 550 days), standard weight ratio, grade
and post-weaning index.

Group averages computed and printed out include 205 day weight and index
(if available), final weight, age, days on test, average daily gain, gain ratio,
standard age weight, standard weight ratio score, visual grade, control columns
and index. The 205 day weight and weaning index are printed to allow an easy
comparison of pre- and post-weaning performance. The control columns are avail-
able for the rancher to use to store numerically coded information such as
pastures the calves were raised in, creep feeding, color pattern or pigmentation.

The computed data is listed three ways: (1) by calf number, (2) ranked
by standard age weight (365 or 550 days) and (3) by sire group.


NOTATIONS AND FORMULAS USED FOR THESE COMPUTATIONS ARE AS FOLLOWS:

1. Days on test = DOT

2. Age at final weight = AFW

3. Weight per day of age = WDA
WDA = Final weight AFW

4. Average daily gain = ADG
ADG = (Final weight Initial weight) + DOT

5. Weight at standard age (365 or 550 days) = SW
SW = Final weight + [(365 or 550 AFW) x ADG]

6. Final weight ratio = (SW + group average SW) x 100

7. Pbst-weaning index = [(SW x Grade) group average index] x 100

8. ADG ratio (ADG of individual + group average ADG) x 100

Examples of yearling (365 and 550 days) post-weaning performance evalu-
ation are attached.



For further information contact your local Extension Agent or:

Dr. R. S. Sand
402 Rolfs Hall
Gainesville, Florida 32611
(904) 392-1916








I, :-'




k' .



C ANIMAL BR S


,68
,68
.68
,.68
,1,68
68


13847
14047
14147
4095
4215
4355


.N = 6


0
I--4


i-4




SIR!.


929
456
929
153
153
153


o


cIA





DAM


8547
10547
5447
75K
5983
252K


AVERAGES=


u

HE Z



205
WT

471
317
392
482
406
435


Z Lo-
3-
I N-
DEX

132
77
100
IOU
130
105
12U


<0u
7. r-1
I'. :,
FIN
WT

11P5
995
1100
1155
1095
1225


1-1
I-E
Z/1 _



Lw U H
0 H 1,
<'1 ` -3 &
DAY
AGE TST


615
591
583
632
619
613


346
346
346
346
346
346


z
1-4
-c
LJ U
oo




GN
ADG RTO


163
181
181
150
172
197


94
104
104
86
99
113


Li >-
: o
'C :c
03

550
WT

1079
921
1031
1032
976
1101


n-o




101
3
550
R70O

105
90
101
101
95
108


n



"- 1.U LO0 0 -
-> v--

CON- IN-,
SCORE TROL VEX


111
79
102
98
96
114


417 111 1126 610 346 174 100 1023 100 0 13


CALF tIli;:I B R


HERD NO. 000


POST WEAN- LISI'


ANIMAL BR S


SIRE


DAM


205 IN- FIN DAY
WT DEX WT AGE TST


GN 550 550
ADG RTO WT RTO


CON- IN-
SCORE IROL DEX


,68

.. 68
68
,,68
S ..68


N = 6 AVERAGES=



IEi.,1 IO. 000


417 111 1126 610 346 174 100 1023 100 0 13


POST WEAN- DAY I.]S PAGE


. ANIMAL

68 4355
68 4095
,68 4215

,.N = 3


BR S SIRE


02 1
02 1
02 1


0 153
0 153
0 153


AVERAGES=


S60 14,47 02 1 0 455


AVERAGES=


DAM


252K
75K
5983


205 IN- FIN
WT DEX HT


DAY
AGE TST


435 120 1225 613 346 197
482 130 1155 632 346 150
406 105 1095 619 346 172


GN 550 550
ADG RTO WT RTO


113 1101
86 1032
99 976


CNj- IN-
SCUkE IkOl. DEX


0 14
0 12
0 j3


441 118 1158 621 346 173 99 1036 101 0 13


65 10547 317 77 995 591 346 181 104 921 90 0 !0

317 77 995 591 346 181 104 921 90 0 10


, 68 13847 02 1
68 14147 02 1


0 929
0 929


8547 471 132 1185 615 346 163 94 1079 J05
5447 392 100 1100 588 34f 161. 104 1031 101


AVERAGES =


HfILED NO. COO


432 116 1143 602 316 172 99 1055 103 0 14 1 107

SIRE
POST WEAN-AVELPAAi: PAGE


PAGE 1


1 100


4355
13847
4095
14147
4215
14047


153
929
153
929
153
456


252K
8547
75K
5447
5983
10547


435
471
482
392
406
317


1225
1185
1155
1100
1095
995


613
615
632
588
619
591


346
346
346
346
346
346


1101
1079
1032
1031
976
92[


108
105
101
lOu
401
95
90


114
111
98
102
9f,
79


1 e10


I,
,,N = 1


N = 2


1 114
1 Se
1 96

1 103


1 79

1 79


1 111
1 102


0 14
0 13















3

ANIMAL BR S
.Il


&
,68 138'
68 140'
.60 141'
68 409!
A 68 421!
.;68 435!

IN = 6


47 02 1
47 02 1
47 02 1
5 02 1
5 02 1
5 02 1


- 205 IN-
WT DEX


SIRE


929
456
929
153
153
153


AVERAGES=


SHERD NO. 000


POST


8547
10547
5447
75K
5983
252K


471
317
392
482
406
435


132
77
100
130
105
120


FIN DAY GN
WT AGE TST ADG RTO


880
655
785
885
795
880


140
140
140
140
140
140


186
204
221
179
211
239


90
99
107
87
102
1A6


417 111 813 404 140 207 100


CALF NUMBER
HEAN- ..LIST PAGE


S-- --- --205 IN-- FIN DAY
Vy ANIMAL BR S SIRE DAM WT DEX HT AGE TST


365 365
WT RTO


798
614
747
776
694
780


109
84
102
106
94
106


733 100


1



GN 365 365
ADG RTO HT RTO


CON- IN-;
SCORE TROL UEX!

0 14 1 114'
0 10 1 73
0 13 1 103
0 12 1 0
0 13 1 95
0 14 1 112

0 13 1 100G







CON- TN-'
SCORE TROL bFX


,68 13847
,68 4355
68 4095
,68 14147
.68 4215
,68 14047

,N. 6


929
153
153
929
153
456


AVERAGES=


ERD NO 000
, HERD NO. 000


, ANIMAL BR S SIRE ODAM.


8547
252K
75K
5447
5983
10547


471
435
482
392
406
317


132
120
130
100
105
77


409
407
426
382
413
385


140
140
140
140
140
140


186
239
179
221
211
204


90
116
07
107
102
99


417 111 813 404 140 207 100


798
780
776
747
694
614


109
106
106
102
94
84


735 100 0 13


365
POST WEAN- AY LIST PACE


205 IN- FIN
WT DEX WT


DA'
AGE TS"


68 4355 02 1 -0 153 :62 252K 435 120 880 407 141
,68 4095 02 1 0 153 55 75K 482 130 805 426 141
S 60g 4215; 02 1. 0 153 65 5983 406 105 795 413 14:

.. N = 3 AVERAGES .441 118 853 415 14'


.68 ;::;1404: 02. 1' 0 456 65 10547 317 77 655 385 141

.:.iN 1 AVERAGES= 317 77 655 385 14


;;! 60 13 47 02 1 0 929 63 8547 471 132 800 409 14'
:: ""'-::il 2 0 929 58 5447 392 100 775 382 141

S::'::- 2 AV ... ERAGES 432 116 833 396 14
SIRE
..:H.':. IERD :NO.-. 6000 POST IJEAN- AV.ERAGB PAGE


Y. GN
r ADG RTD

D 239 116,
0 179 87
3 211 102


365
WT

700
776
694


365
RTO SCORE

106 0 14
106 0 12
94 0 13


0 210 102 750 102 0 13


0. 204


0 204 99


U 186 90
0 221 107


99 ;614 84,'


0 10


614 84 0 10


798
747


10O
102


0 20 9.9 '773 106


= . .. ,"



:.:* !"


0 14
0 13

0 14


1 114:
1 J12.
1 10,.
1 103 ,
1 9!
1 7.1
i





i
1 100








CON- 1IN-
TROL DEX

1 112
1 102
1 9'

1 101


1 7*f

1 7.'


1 114 i
1 103

1 109:

I^



** .
1


- . "




I






NiO COOPERATIVE EXTENSION SERVICE SOUTHERN STATES


/ SOUTHERN REGIONAL

BEEF COW-CALF HANDBOOK

SR-2000


Daily Nutrient Requirements of Beef Cattle



Prepared by James E. Ross and Homer B. Sewell, Department of Animal Husbandry, College of
Agriculture, University of Missouri.

From Nutrient Requirements of Beef Cattle Fifth Revised Edition, National Research Council, 1976.

These values have been converted from metric system and to even 100 Ibs. of body weight. Figures
have been rounded to the nearest appropriate values.


2000.1







TABLE 1A


NUTRIENT REQUIREMENTS FOR GROWING-FINISHING STEER CALVES AND YEARLINGS
(DAILY NUTRIENTS PER ANIMAL)


DMb Roughageb
Ibs. Pct.


DP NEm NEg TDN b .
Ibs. Meal Mcal Ibs.


Ca
Ibs.


P Vitamin A
Ibs. Thou. IU


1000 2.0
1000 2.5


300
300
300
300
300

400
400
400
400
400

500
500
500
500
500

600
600
600
600
600
600

700
700
700
700
700

800
800
800
800

900
900
900
900


0 14.2 100


22.5 45-55
22.1 20-25


1000 3.0d 20.8 <15


15.4 100
23.1 45-55
22.9 20-25
22.0 <15


0
1.0
1.5
2.0
2.5

0
1.0
1.5
2.0
2.5

0
1.0
1.5
2.0
2.5

0
1.0
1.5
2.0
2.5
3.0d

0
1.5
2.0
2.5
3.0 d

0
2.0
2.5
3.0d

0
2.0
2.5
3.0d


5.6 100
7.8 70-80
7.9 50-60
7.8 25-30
7.7 <15

7.0 100
10.9 80-90
11.1 70-80
9.9 30-40
9.7 <15

8.7 100
11.4 75-85
12.7 55-65
12.3 45-50
12.1 <15

10.0 100
12.8 65-70
15.5 55-65
15.6 45-55
15.4 20-25
14.4 <15

11.0 100
16.9 55-65
18.9 45-55
17.1 20-25
16.8 <15

12.0 100
17.9 45-55
18.3 20-25
18.3 <15

13.2 100
20.9 45-55
19.7 20-25
19.7 <15


0.48
0.88
1.03
1.14
1.23

0.59
1.19
1.25
1.27
1.35

0.72
1.29
1.34
1.43
1.56

0.81
1.22
1.42
1.63
1.70
1.75

0.92
1.55
1.76
1.81
1.90

1.03
1.78
1.86
1.97

1.13
1.88
1.95
2.04


1.19 0.68 7.58


0.26
0.56
0.70
0.79
0.90

0.33
0.66
0.81
0.85
0.93

0.39
0.73
0.85
0.92
1.00

0.46
0.75
0.89
1.03
1.05
1.15

0.52
0.97
1.12
1.15
1.22

0.59
1.09
1.16
1.24

0.63
1.14
1.21
1.27


0 7.9


1.94 1.13 7.58 5.32 15.5
2.09 1.25 7.58 6.85 17.1
2.16 1.32 7.58 8.21 17.9


1.32
2.09
2.12
2.15


0.75
1.23
1.27
1.33

2000.2


8.14
8.14
8.14
8.14


0 8.4
5.60 16.5
7.38 18.9
8.87 20.6


3.07
3.07
3.07
3.07
3.07

3.81
3.81
3.81
3.81
3.81

4.51
4.51
4.51
4.51
4.51

5.17
5.17
5.17
5.17
5.17
5.17

5.79
5.79
6.79
5.79
5.79

6.41
6.41
6.41
6.41

7.00
7.00
7.00
7.00


0 3.2
1.12 4.6
1.60 5.5
2.15 6.0
2.76 6.5

0 3.9
1.38 6.1
1.98 7.1
2.61 7.6
3.33 8.0

0 4.6
1.53 7.2
2.32 8.3
3.09 9.1
4.04 9.6

0 5.4
1.78 7.2
2.67 10.2
3.54 10.7
4.62 11.4
5.58 12.6

0 6.0
3.05 10.7
3.98 12.2
5.24 12.9
6.28 14.0

0 6.6
4.43 13.0
5.74 14.3
6.98 16.0

0 7.3
4.92 13.8
6.58 15.6
7.48 17.1


Wt. a
Ibs.


ADG
Ibs.


.008
.031
.042
.053
.062

.011
.031
.040
.051
.062

.013
.031
.040
.051
.060

.018
.033
.040
.049
.057
.066

.020
.041
.049
.055
.064

.022
.044
.051
.057

.024
.046
.051
.055

.026
.044
.051
.053

.029
.042
.044
.048


.008
.024
.029
.035
.042

.011
.026
.031
.037
.045

.013
.029
.035
.040
.044

.018
.029
.035
.042
.046
.051

.020
.036
.042
.049
.051

.022
.040
.044
.049

.024
.044
.046
.049

.026
.044
.049
.051

.029
.042
.044
.049


1000


1100
1100
1100
1100







NUTRIENT REQUIREMENTS FOR GROWING-FINISHING HEIFER CALVES AND YEARLINGS
(DAILY NUTRIENTS PER ANIMAL)


DM Roughage
Ibs. Pct.


Wt.
Ibs.

300
300
300
300
300

400
400
400
400
400

500
500
500
500
500

600
600
600
600
600

700
700
700
700
700

800
800
800
800
800

900
900
900
900
900

1000
1000
1000
1000
1000


0
1.0
1.5
2.0
2.5

0
1.0
1.5
2.0
2.5

0
1.0
1.5
2.0
2.5

0
1.0
1.5
2.0
2.5

0
1.0
1.5
2.0
2.5

0
1.0
1.5
2.0
2.5

0
1.0
1.5
2.0
2.4

0
1.0
1.5
2.0
2.2


5.8
8.1
3.1
8.2
8.2

7.1
11.4
11.6
10.6
10.1

8.4
13.6
13.4
12.3
12.4

9.6
15.2
13.6
13.9
14.7

10.8
17.0
15.6
16.0
16.9

12.0
18.4
17.9
18.0
18.4

13.2
18.5
18.9
18.6
18.4

14.2
20.0
20.1
19.5
18.7


100
70-80
50-60
25-30
<15

100
75-85
65-75
30-40
<15

100
80-90
60-70
35-45
<15

100
80-90
55-65
35-45
<15

100
80-90
55-65
35-45
<15

100
75-85
55-65
25-35
<15

100
70-80
50-60
20-25
<15

100
70-80
55-65
25-35
<15


NE,
Mcal


0.48
0.90
1.05
1.14
1.30

0.61
1.12
1.25
1.30
1.40

0.72
1.30
1.35
1.45
1.52

0.81
1.39
1.41
1.48
1.68

0.92
1.47
1.52
1.58
1.78

1.03
1.61
1.63
1.69
1.80

1.12
1.57
1.74
1.76
1.81

1.21
1.71
1.79
1.83
1.83


NE,
Mcal


0.28
0.58
0.70
0.79
0.93

0.35
0.71
0.81
0.85
0.96

0.41
0.77
0.83
0.90
1.04

0.46
0.82
0.85
0.94
1.08

0.52
0.87
0.90
0.99
1.10

0.57
0.91
0.92
1.01
1.12

0.63
0.92
0.99
1.04
1.09

0.68
0.98
1.03
1.06
1.06


Vitamin A
Thou. IU


3.06
3.06
3.06
3.06
3.06

3.74
3.74
3.74
3.74
3.74

4.50
4.50
4.50
4.50
4.50

5.16
5.16
5.16
5.16
5.16

5.79
5.79
5.79
5.79
5.79

6.40
6.40
6.40
6.40
6.40

6.99
6.99
6.99
6.99
6.99

7.57
7.57
7.57
7.57
7.57


0
1.13
1.80
2.41
3.21

0
1.38
2.24
2.99
3.99

0
1.76
2.65
3.54
4.73

0
1.89
3.08
4.05
5.43

0
2.13
3.48
4.55
5.96

0
2.35
3.77
5.04
6.69

0
2.57
4.09
5.54
6.99

0
2.77
4.36
5.98
6.75


3.2
4.8
5.7
6.3
6.6

4.2
6.8
7.6
8.1
9.0

4.7
8.0
8.8
9.5
10.8

5.4
8.9
9.7
10.7
12.5

5.9
9.5
10.9
12.1
13.8

6.6
11.1
12.2
13.4
15.4

7.4
11.8
13.3
14.1
16.1

7.9
12.6
14.2
15.7
16.3


2000.3


.008
.031
.042
.053
.064

.011
.029
.031
.051
.062

.013
.029
.040
.048
.055

.015
.031
.037
.046
.055

.020
.028
.035
.042
.051

.022
.033
.033
.037
.044

.024
.033
.035
.037
.042

.026
.035
.037
.035
.042


.008
.024
.031
.037
.044

.011
.026
.030
.037
.044

.013
.029
.035
.037
.042

.015
.031
.033
.037
.045

.019
.028
.031
.037
.044

.022
.033
.033
.037
.040

.024
.033
.035
.037
.040

.026
.035
.037
.035
.042







REFERENCES TABLE 1A


a) Average weight for a feeding period.

b) Dry matter consumption, ME and TDN allowances are based on NE requirements and the general
types of diet indicated in the roughage column. Most roughages will contain .86 to 1 M cal of ME/lb
dry matter and 90-100% concentrate diets are expected to contain 1.4-1.5 M cal of ME/lb.


c) TDN was calculated by assuming 1.64 Mcal of ME/lb of TDN.

d) Most steers or heifers of the weight indicated, and not exhibiting compensatory growth, will fail to
sustain the energy intake necessary to maintain this rate of gain for an extended period.



TABLE 1B

NUTRIENT REQUIREMENTS FOR PREGNANT YEARLING HEIFERS-LAST THIRD OF PREGNANCY
(DAILY NUTRIENTS PER ANIMAL)


DMb Roughageb
Ibs. Pct.


15.6
19.6
21.1

16.6
21.5
23.4

18.2
23.4
25.8


100
100
85-100

100
100
85-100

100
100
85-100


TP DP
Ibs. Ibs.


1.37 .79
1.75 1.00
1.91 1.10

1.46 .84
1.88 1.08
2.04 1.17

1.58 .91
2.05 1.18
2.24 1.29


NEm NE,
Mcal Mcal


5.79
5.79
5.79


.84
1.86
2.43


6.41 .91
6.41 2.06
6.41 2.70

7.0 .98
7.0 2.25
7.0 2.94


NUTRIENT REQUIREMENTS FOR


DM Roughaged
Ibs. Pct.


DRY PREGNANT MATURE COWS-MIDDLE THIRD
(DAILY NUTRIENTS PER ANIMAL)


TP DP
Ibs. Ibs.


NEm NEg
Mcal Mcal


OF PREGNANCY

P Vitamin A
Ibs. Thou. IU


- 12.5 100

- 13.6 100


14.8 100

15.9 100


- 17.0 100

- 18.0 100

- 19.1 100


0.73 0.34 6.4


- 6.8 .023


0.79 0.37 7.0 ,- 7.4 .025


0.87 0.40 7.6

0.94 0.44 8.1

0.99 0.47 8.7

1.06 0.51 9.2


- 8.0 .027

- 8.6 .029

- 9.1 .030

- 9.6 .032


1.13 0.54 9.8 10.2 .034


2000.4


Vitamin A
Thou. IU


TDNb.c
Ibs.


8.1
10.8
12.2

8.5
11.6
13.2

9.3
12.5
14.2


.035
.044
.049

.036
,045
.049

.038
.049
.049


.035
.044
.043

.036
.045
.048

.038
.049
.049


1000

1100

1200

1300

1400


.023 17

.025 18

.027 19

.029 21

.030 22

.032 23

.034 25






NUTRIENT REQUIREMENTS FOR DRY PREGNANT MATURE COWS-LAST THIRD OF PREGNANCY
(DAILY NUTRIENTS PER ANIMAL)

Wt. ADG DM Roughaged TP DP NE, NE, TDN Ca P Vitamin A
SIbs. Ibs. Ibs. Pct. Ibs. Ibs. Mcal Mcal Ibs. lbs. Ibs. Thou. IU


14.3 100

15.5 100

16.7 100

17.9 100

19.2 100

20.5 100

21.9 100


0.94 0.43 8.0

1.08 0.46 8.6

1.10- 0.50 9.2

1.12 0.53 9.7

1.18 0.56 9.9

1.24 0.59 10.1

1.30 0.63 10.3


- 8.2

- 8.8

- 9.4

- 10.0

- 10.6

11.2

- 11.7


.028 .028

.030 .030


.032

.034

.036

.038

.040


.032

.034

.036

.038

.040


COWS NURSING CALVES-AVERAGE MILKING ABILITYe-FIRST 3 TO 4 MONTHS POSTPARTUM
(DAILY NUTRIENTS PER ANIMAL)

Wt. ADG DM Roughage TP DP NE,,, NE, TDN Ca P Vitamin A
Ibs. Ibs. Ibs. Pct. Ibs. Ibs. Mcal Mcal Ibs. Ibs. Ibs. Thou. IU


- 18.4 100


1.69 0.99 9.4


- 9.9 .054


.054


0 19.4 100 1.78 1.05 9.9 10.5 .055 .056 36

10 20.5 100 1.88 1.11 10.5 11.1 .058 .058 37

10 21.6 100 1.98 1.17 11.1 11.7 .060 .060 39

0 22.7 100 2.08 1.23 11.6 12.3 .062 .062 41

0 23.8 100 2.18 1.29 12.1 12.9 .062 .062 43

0 24.9 100 2.29 1.35 12.7 13.5 .063 .063 44

COWS NURSING CALVES-SUPERIOR MILKING ABILITY--FIRST 3 TO 4 MONTHS POSTPARTUM
(DAILY NUTRIENTS PER ANIMAL)

ADG DM Roughage TP DP NE. NE, TDN Ca P Vitamir
bs. Ibs. Pct. ibs. Ibs. Mcal Mcal Ibs. Ibs. Ibs. Thou. I


nA
U


- 22.8 100'

- 23.8 100

- 24.9 100

- 26.0 100

- 27.0 100

- 28.1 100

- 29.2 100


2.48 1.45 12.5

2.60 1.52 13.0

2.72 1.59 13.6

2.84 1.67 14.2

2.95 1.74 14.8

3.06 1.81 15.4

3.18 1.88 16.0
2000.5


800

900

1000

1100

1200

1300

1400


10


80

90

100

110

120

130

14C


800

900

1000

1100

1200

1300

1400


- 13.0

- 13.6

- 14.2

- 14.8

- 15.4

- 16.0

- 16.6


.097

.098

.099

.100

.101

.101

.101


.087

.089

.091

.093

.095

.095

.095


.ww







NUTRIENT REQUIREMENTS FOR BULLS, GROWTH AND MAINTENANCE-MODERATE ACTIVITY
(DAILY NUTRIENTS PER ANIMAL)

Wt. ADG DM Roughage TP DP NE. NE, TDN Ca P Vitamin A
Ibs. Ibs. Ibs. Pct. Ibs. Ibs. Meal Mcal Ibs. Ibs. Ibs. Thou. IU

700 2.2 20.5 70-75 2.09 1.29 5.6 3.8 13.2 .064 .053 37

900 2.0 24.7 70-75 2.33 1.39 6.9 4.1 15.8 .052 .051 44

1100 1.5 26.9 80-85 2.36 '1.36 8.5 3.7 16.5 .048 .048 48

1300 1.1 26.2 80-85 2.29 1.32 9.7 3.0 15.9 .047 .047 47

1500 0.7 27.9 90-100 2.35 1.33 10.8 2.0 15.2 .050 .050 49

1700 24.6 100 1.90 1.07 11.9 0 12.3 .040 .040 40

2000 25.2 100 2.15 1.22 13.4 0 13.9 .046 .046 45

2200 27.3 100 2.32 1.32 14.4 0 15.2 .049 .049 49



REFERENCES TABLE 1B

a) Average weight for a feeding period.

b) Dry matter consumption, TDN requirements are based on the general type of diet indicated in the
roughage column.
c) Approximately .65 to 1 Ib. of weight gain/day over the last third of pregnancy is accounted for by
the products of conception. These nutrients and energy requirements include the quantities esti-
mated as necessary for concepts development.

d) Average quality roughage containing about .86-.91 Mcal ME/lb dry matter.

e) 10 to 12 Ibs. of milk/day. Nutrients and energy for maintenance of the cow and for milk production
are included in these requirements.

f) 20 to 24 Ibs. of milk/day. Nutrients and energy for maintenance of the cow and for milk production
are included in these requirements.

g) Good quality roughage containing at least .91 Mcal ME/lb dry matter.


2000.6






TABLE 2A


NUTRIENT REQUIREMENTS FOR GROWING-FINISHING STEER CALVES AND YEARLINGS
(NUTRIENT CONCENTRATION IN DIET DM)


DMC Roughage
Ibs. Pct.


DP NEf NE' TDNd'
Pct. Mcal-lb Mcal-lb Pct.


300
300
300
300
300

400
400
400
400
400

500
500
500
500
500


600
600
600
600
600
600

700
700
700
700
700

800
800
800
800

900
900
900
900

1000
1000
1000
1000

S1100
1100
1100
1100


0
1.0
1.5
2.0
2.5
3.0e

0
1.5
2.0
2.5
3.0e

0
2.0
2.5
3.0e

0
2.0
2.5
3.0e

0
2.0
2.5
3.00

0
2.0
2.5
2.9d


5.6 100
7.8 70-80
7.9 50-60
7.8 25-30
7.7 <15

7.0 100
10.9 80-90
11.1 70-80
9.9 30-40
9.7 <15

8.7 100
11.4 75-85
12.7 55-65
12.3 45-50
12.1 < 5

10.0 100
12.8 65-70
15.5 55-65
15.6 45-50
15.4 20-25
14.4 <15

11.0 100
16.9 55-65
18.9 50-60
17.1 20-25
16.8 <15

12.0 100
17.9 45-55
18.3 20-25
18.2 <15

13,2 100
20.9 45-55
19.7 20-25
19.7 <15

14.2 100
22.5 45-55
22.1 20-25
20.8 <15

15.4 100
23.1 45-55
22.9 20-25
22.0 <15


Wt. b
Ibs.


ADG c
Ibs.


4.7
7.2
8.9
10.0
11.7

4.6
6.1
7.3
8.6
9.6

4.5
6.4
6.7
7.5
8.3


8.6
11.3
13.0
14.6
16.0

8.3
10.9
11.3
12.8
13.9

8.3
11.3
10.6
11.6
12.9

8.1
9.5
9.2
10.5
11.0
12.2

8.4
9.2
9.3
10.6
11.3

8.6
9.9
10.2
10.8

8.6
9.2
9.9
10.4

8.4
8.6
9.4
10.4

8.6
9.0
9.3
9.7


0 57
.42 60
.45 70
.54 77
.62 84

0 55
.34 56
.42 64
.51 77
.59 83

0 53
.46 63
.39 65
.50 74
.55 79

0 54
.42 56
.32 66
.41 69
.51 73
.62 86

0 55
.35 63
.37 65
.52 75
.59 83

0 55
.48 70
.54 78
.60 86

0 55
.43 71
.59 79
.62 86

0 55
.52 69
.53 80
.62 86

0 55
.46 72
.56 83
.62 86


2000.7


.19
.18
.20
.22






NUTRIENT REQUIREMENTS FOR GROWING-FINISHING HEIFER CALVES AND YEARLINGS
(NUTRIENT CONCENTRATION IN DIET DM)


Wt. AbG
Ibs. Ibs.


300
300
300
300
300

400
400
400
400
400

500
500
500
500
500

600
600
600
600
600

700
700
700
700
700

800
800
800
800
800

900
900
900
900
900

1000
1000
1000
1000
1000


0
1.0
1.5
2.0
2.5

0
1.0
1.5
2.0
2.5

0
1.0
1.5
2.0
2.5

0
1.0
1.5
2.0
2.5

0
1.0
1.5
2.0
2.5e

0
1.0
1.5
2.0
2.5e

0
1.0
1.5
2.0
2.4e

0
1.0
1.5
2.0
2.5e


DMc Roughage
Ibs. Pct.


5.8
8.1
8.1
8.2
8.2

7.1
11.4
11.6
10.6
10.1

8.4
13.6
13.4
12.3
12.4

9.6
15.2
13.6
13.9
14.7

10.8
17.0
15.6
16.0
16.9

12.0
18.4
17.9
18.0
18.4

13.2
18.5
18.9
18.6
18.4

14.2
20.0
20.1
19.5
18.7


100
70-80
50-60
25-30
<15

100
75-85
65-75
30-40
<15

100
80-90
60-70
35-45
<15

100
80-90
55-65
35-45
<15

100
80-90
55-65
35-45
<15

100
75-85
55-65
25.35
<15

100
70-80
50-60
20-25
<15

100
70-80
55-65
25-35
<15


TP DP NE',
Pct. Pct. Mcal-lb


8.3
11.1
13.0
13.9
15.9

8.6
9.8
10.7
12.3
13.9

8.6
9.6
10.1
11.8
12.3

8.4
9.1
10.4
10.6
11.4

8.5
8.6
9.7
9.9
10.5

8.6
8.8
9.1
9.4
9.8

8.5
8.5
9.2
9.5
9.8

8.5
8.6
8.9
9.4
9.8


4.8
7.2
8.6
9.6
11.3

4.9
6.2
7.0
8.0
9.5

4.9
5.7
6.2
7.3
8.4

4.8
5.4
6.3
6.8
7.3

4.8
5.1
5.8
6.1
6.5

4.8
4.9
5.1
5.6
6.1

4.8
5.0
5.3
5.6
5.9

4.8
4.9
5.1
5.4
5.7


2000.8


NE'
Mcal-lb


TDNd'
Pct.






REFERENCES TABLE 2A

a) The concentration of vitamin A in all diets for finishing heifers is 1000 IU/lb of dry diet.

Sb) Average weight for a feeding period.

c) Dry matter consumption, ME and TDN allowances are based on NE requirements and the general
type of diet indicated in the roughage column. Most roughages will contain .86 to 1 Mcal of ME/lb
dry matter and 90-100%/ concentrate diets are expected to have 1.4 to 1.5 Mcal of ME/lb.

d) TDN was calculated by assuming 1.64 Mcal/lb TDN.

e) Most heifers of the weight indicated, and not exhibiting compensatory growth, will fail to sustain
the energy intake necessary to maintain this rate of gain for an extended period.

f) Due to conversion and rounding variation, the figures in these columns may not be in exact agree-
ment with a similar energy concentration figure calculated from the data of Table 1A.


TABLE 2B

NUTRIENT REQUIREMENTS FOR PREGNANT YEARLING HEIFERS-LAST THIRD OF PREGNANCY
(NUTRIENT CONCENTRATION IN DIET DM)

Wt.b ADG DMc Roughage TP DP NE, NE, TON Ca P
Ibs. Ibs. Ibs. Pct. Pct. Pct. Mcal-lb Mcal-lb Pct. Pct. Pct.

700 1.0d 15.6 100e 8.8 5.1 .49 .17 52 .23 .23
700 1.5 19.6 100 8.8 5.1 .49 .17 52 .21 .21
700 1.8 21.1 85-100 9.0 5.3 .56 .27 58 .21 .21

800 1.0d 16.6 100 8.7 5.0 .49 .17 52 .22 .22
800 1.5 21.5 100 8.7 5.0 .49 .17 52 .20 .20
800 1.8 23.4 85-100 8.7 5.0 .54 .23 56 .20 .20

900 1.0d 18.2 100 8.7 5.0 .49 .17 52 .21 .21
900 1.5 23.4 100 8.7 5.0 .49 .17 52 .20 .20
900 1.8 25.8 85-100 8.7 5.0 .53 .23 55 .19 .19


NUTRIENT REQUIREMENTS FOR DRY PREGNANT MATURE COWS-MIDDLE THIRD OF PREGNANCY
(NUTRIENT CONCENTRATION IN DIET DM)
Wt. ADG DM Roughage TP DP NEm NEg TDN Ca P
Ibs. Ibs. Ibs. Pct. Pct. Pet. Mcal-lb Mcal-lb Pct. Pct. Pct.

800 12.5 100e 5.9 2.8 .49 52 .18 .18

900 13.6 100 5.9 2.8 .49 52 .18 .18

1000 14.8 100 5.9 2.8 .49 52 .18 .18

1100 15.9 100 5.9 2.8 .49 52 .18 .18

1200 17.0 100 5.9 2.8 .49 52 .18 .18

1300 18.0 100 5.9 2.8 .49 52 .18 .18

1400 19.1 100 5.9 2.8 .49 52 .18 .18
2000.9






NUTRIENT REQUIREMENTS FOR DRY PREGNANT MATURE COWS-LAST THIRD OF PREGNANCY
(NUTRIENT CONCENTRATION IN DIET DM)

Wt. ADG DM Roughage TP DP NEm NE, TDN Ca p
Ibs. Ibs. Ibs. Pct. Pct. Pct. Mcal-lb Mcal-lb Pct. Pct. Pct.

800 .9" 14.3 100e 5.9 2.8 .49 52 .18 .18

900 .9 15.5 100 5.9 2.8 .49 52 .18 .18

1000 .9 16.7 100 5.9 2.8 .49 52 .18 .18

1100 .9 17.9 100 5.9 2.8 .49 52 .18 .18

1200 .9 19.2 100 5.9 2.8 .49 52 .18 .18

1300 .9 20.5 100 5.9 2.8 .49 52 .18 .18

1400 .9 21.9 100 5.9 2.8 .49 52 .18 .18

NUTRIENT REQUIREMENTS FOR COWS NURSING CALVES-AVERAGE MILKING ABILITYf
FIRST 3 TO 4 MONTHS POSTPARTUM (NUTRIENT CONCENTRATION IN DIET DM)
Wt. ADG DM Roughage TP DP NEm NE, TDN Ca P
Ibs. Ibs. Ibs. Pct. Pct. Pct. Mcal-lb Mcal-Ib Pct. Pct. Pct.

800 18.4 100" 9.2 5.4 .49 52 .29 .29

900 19.4 100 9.2 5.4 .49 52 .28 .28

1000 20.5 100 9.2 5.4 .49 52 .28 .28

1100 21.6 100 9.2 5.4 .49 52 .28 .28

1200 22.7 100 9.2 5.4 .49 52 .27 .27

1300 23.8 100 9.2 5.4 .49 52 .25 .25

1400 24.9 100 9.2 5.4 .49 52 .25 .25

NUTRIENT REQUIREMENTS FOR COWS NURSING CALVES-SUPERIOR MILKING ABILITY g
FIRST 3 TO 4 MONTHS POSTPARTUM (NUTRIENT CONCENTRATION IN DIET DM)

Wt. ADG DM Roughage TP DP NE. NE, TDN Ca P
Ibs. Ibs. Ibs. Pct. Pct. Pct. Mcal-lb Mcal-lb Pct. Pct. Pct.

800 22.8 100 h 10.9 6.4 .53 .55 .44 .39

900 23.8 100 10.9 6.4 .53 .55 .42 .38
1000 24.9 100 10.9 6.4 .53 .55 .40 .37

1100 26.0 100 10.9 6.4 .53 .55 .39 .36

1200 27.0 100 10.9 6.4 .53 .55 .37 .35

1300 28.1 100 10.9 6.4 .53 .55 .36 .34

1400 29.2 100 10.9 6.4 .53 .55 .35 .33
2000.10






NUTRIENT REQUIREMENTS FOR BULLS, GROWTH AND MAINTENANCE-MODERATE ACTIVITY
(NUTRIENT CONCENTRATION IN DIET DM)

Wt. ADG DM Roughage TP DP NE, NE, TDN Ca P VitaminA
Ibs. Ibs. Ibs. Pct. Pct. Pct. Mcal-lb Mcal-lb Pct. Pct. Pct. Thou. lU

700 2.2 20.5 70-75 10.2 6.3 .64 .32 64 .31 .26 37

900 2.0 24.7 70-75 9.4 5.6 .64 .30 64 .21 .21 44

1100 1.5 26.9 80-85 8.8 5.1 .60 .30 61 .18 .18 48

1300 1.1 26.2 80-85 8.5 5.1 .60 .30 61 .18 .18 47

1500 0.7 27.9 90-100h 8.5 4.8 .53 .26 55 .18 .18 49

1700 24.6 100h 8.5 4.8 .53 0 55 .18 .18 40

2000 25.2 100h 8.5 4.8 .53 0 55 .18 .18 45

2200 27.3 100h 8.5 4.8 .53 0 55 .18 .18 49




REFERENCES TABLE 2B

a) The concentration of vitamin A in all diets for pregnant heifers and cows is 1273 IU/lb dry diet;
for lactating cows and breeding bulls, 1773 IU/lb.

b) Average weight for a feeding period.

c) Dry matter consumption, ME and TDN requirements are based on the general type of diet indicated
in the roughage column.

d) Approximately .66 to 1.1 Ib of weight gain/day over the last third of pregnancy is accounted for by
the products of conception.

e) Average quality roughage containing about .86 to .91 Mcal ME/lb dry matter.

f) 10 to 12 Ib of milk/day.

g) 20 to 24 Ib of milk/day.

h) Good quality roughage containing .91 Mcal Me/lb. dry matter.

i) Due to conversion and rounding variation, the figures in these columns may not be in exact agree-
ment with a similar figure calculated from the data in Table 1B.







COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
Cooperative Extension Service, IFAS, University of Florida
end United States Department of Agriculture, Cooperating
K. R. Tefertiller, Director


2000.11





E1 COOPERATIVE EXTENSION SERVICE SOUTHERN STATES -




SOUTHERN REGIONAL

BEEF COW-CALF HANDBOOK

$SR 2001


Balancing Rations for Beef Cattle
Nelson Gay, J. A. Boling and C. W. Absher, University of Kentucky


Approximately 70 to 80% of the cost of producing
beef is accounted for by feed. This is true whether the feed
is forage, harvested, stored farm-raised, or purchased
feed. Therefore, the need to use feed efficiently is ob-
vious. Purchased feeds (supplements, minerals, and pre-
mixes) usually cost 3 or 4 times as much as home-raised
feeds on a unit basis, so they need to be used to greatest
advantage. Beef cattle rations are balanced most effic-
iently and economically by feeding supplements that
furnish only those nutrients missing in the home-raised
feeds.
The "Whys" of Balanced Rations:
A ration is the feed an animal receives in a 24-hour
period. A balanced ration is one that furnishes the
nutrients needed, in the proper amounts and propor-
tions, to allow animals to fulfill a specific purpose (such as
maintenance, growth, gestation or lactation).
Many different feeding situations exist in the field. A
balanced ration for a dry pregnant brood cow is not a
balanced ration for a cow nursing a calf and being rebred.
A cowman or cattle feeder needs to have considerable
knowledge of the specific nutrient needs of different ani-
mals. He also needs to know the nutrient content of avail-
able feeds.


Balancing Rations for Beef Cattle Age, weight, stage of
production and expected performance of cattle as well as
feed composition must be considered when balancing
rations for beef cattle.


Overfeeding or underfeeding is expensive.
Excessive gains on females may result in impaired
reproduction and mothering ability. Slow gains on steers
are likely to be inefficient and costly. Feeding energy for
rapid gain but only enough protein for slow growth rate is
poor economy since feed conversion will be poor.
The "Hows" of Ration Balancing:
Balanced rations are "balanced" according to
feeding standards. Standards list the daily nutrient
requirements of different classes of beef cattle for
different levels of production. Standards or averages for
nutrient content of different feedstuffs are also neces-
sary. The standards used in this publication, are taken
from the NAS, (National Academy of Science), National
Research Council's "Nutrient Requirements of Beef
Cattle", Fourth Edition, 1970, reprinted in this hand-
book as SR-2000. NRC requirements are based on re-
search observations across the country.
Definition of Terms
Calcium A major mineral that is important to the
development of teeth and skeleton. Grains are very low in
calcium while legume hays are relatively high. Cattle on
high roughage rations generally receive an adequate
amount of calcium. Calcium is a cheap mineral to supply
since limestone contains 34-36%.
Concentrate In feeding practice a concentrate is a feed or
feed mixture that supplies the primary nutrient, energy
and contains less than 18% crude fiber. Corn, wheat,
barley, oats and mill feeds are examples of concentrates.
Daily feed is expressed in pounds of dry matter. These
amounts are not necessarily all an animal can consume,
e.g., the 1000 lb. dry cow can eat more than 15 lbs. per
day.
Dry Matter The feed remaining after all water is re-
moved. Dry matter varies from 25-40% in silages,
averages 85% in no. 2 corn and 90% in hay.
Feed Intake Factors such as age, size and flesh condition
affect feed intake. In general, thin, young animals will
consume more feed per unit of body weight than will the
older, more fleshy animals. An animals eats to satisfy its
energy needs; therefore, it will eat more of a ration con-
2001.1





training 60% TDN than one containing 70% TDN. Intake
of dry matter will usually vary between 2-3% of body
weight daily. For example, a thin 600 lb. steer can be ex-
pected to eat 12-18 lb. of dry matter.
Nutrient Any feed component or group of feed compo-
nents of similar chemical composition that aid in the
support of animal life. Protein, carbohydrate, fat,
minerals and vitamins are examples. Carbohydrate, fat &
excess protein are all used in the animal body as energy.
Phosphorus A major mineral important to skeletal
development and metabolic processes. Grains are rela-
tively high in phosphorus and relatively low in calcium.
Phosphorus is an expensive element. Ca-P ratio is not as
critical in ruminant rations as it is with pigs or chickens.
In high grain rations the addition of calcium is generally
necessary.
Roughage Feeds relatively high in fiber (25-35%) and low
in energy are classed as roughage. Hay, silage, cobs,
cottonseed hulls, cornstalks and straw are examples of
roughage.
Supplement Anything added to a ration to improve the
value of the ration. Usually a purchased feed which
supplies nutrients lacking in home-raised feeds, such as
protein.
Total Digestible Nutrients (TDN) A measure of the
energy (caloric content) offeedstuffs. This value is arrived
at as follows: digestible protein + digestible nitrogen free
extract (NFE) + digestible fiber + (2.25 X digestible fat) =
TDN. Grains contain 70-80% TDN, hay about 50% and
silage about 20%. Most feeds contain about the same
gross energy (calories), but the availability of this energy
to the animal varies widely (on dry matter basis).
Total Protein Also referred to as crude protein, is deter-
mined by analyzing feeds for nitrogen (N). Protein in
feeds is approximately 16% N, therefore, multiplying % N
by 6.25 gives total protein. Not all nitrogen in feeds is true
protein, some is in the form of urea, biuret, nitrate, etc.
Protein from urea and other non-protein nitrogen sources
is referred to as protein equivalency.
Digestible Protein As used properly referred to as
"apparent digestible protein." Digestible protein refers to
the proportion of the nitrogen consumed that is ab-
sorbed from the gut. The undigested protein is excreted in
the feces. Other nitrogenous compounds such as dis-
carded body cells are also present in the feces making the
use of "apparent" appropriate. Therefore, digestible pro-
tein is a crude estimate of the usable protein in an animals
ration.
Trace Materials Materials which are used in small
quantities but which are necessary for the metabolic func-
tions of the body. Examples are iron, iodine, cobalt, zinc,
copper, manganese, selenium.
Vitamin A (carotene) A fat soluble vitamin essential in the
diet of beef cattle. Feedstuffs contain no vitamin A except


that added by man. They contain a precursor of vitamin A
called carotene. Many times carotene is not efficiently
converted to vitamin A, so supplementing with synthetic
vitamin A has become common practice. Weathered hay
or dead forage will be deficient in carotene. Vegetative
forage will contain adequate carotene.
Formulating Rations
Actual combination of feedstuffs and the amount of
feed for a specific purpose will depend on:
1. Availability and cost of the feed.
2. Nutrient content of the feed.
3. Size of the animal.
4. Purpose for which fed, e.g. maintenance,
growth finishing or lactation.
Information found in nutrient requirement tables are
averages and contain no margin of safety. Feed composi-
tion tables are also average values. When using them, you
should make a judgment as to the quality of your feed
and adjust the tables accordingly. Although beef cattle re-
quire nutrients other than those listed, the requirements
for these nutrients will likely be met if the ration contains
adequate TDN, crude protein, calcium, phosphorus and
vitamin A.
Combining feedstuffs into a balanced ration re-
quires some trial and error efforts. A systematic ap-
proach to your trial and error efforts will save time. The
following is a suggested routine: (1) What animals are to
be fed? (2) What level of performance? (3) What feed-
stuffs are available? As an example, we are interested in a
wintering ration for replacement heifers. We have clover-
grass hay and ear corn to feed them. We have weighed the
heifers ar weaning and know they weigh 450 pounds.
Within 170 days we would like for them to weigh 650
pounds, since this will be the start of the breeding season.
An average daily gain of 1.2 pounds is needed. Referring
to table 1, (SR-2000) Nutrient Requirements of Beef
Cattle, under growing heifers we see 300, 400 and 500
pound, etc. categories with daily gains of 0, 0.55, 1.10 or
1.65 pounds per day. Specific requirements for daily dry
matter, total protein, digestible protein, TDN, Ca, P and
vitamin A were extracted from this table.
Next we refer to the Feed Composition table of this
publication for the average nutrient composition of our
feedstuffs. The nutrient composition is multiplied by the
amount of feed fed. Nutrient amounts should be totaled
and this value compared with the requirements for the
nutrient. If values for "requirements" and "supplied" do
not correspond, the amounts of various feeds fed need to
be reapportioned.
Example I illustrates a balanced ration for a 500
pound heifer whose desired gain is 1.1 pounds per day.
Examples 2 through 5 illustrates balanced rations for
other classes of cattle utilizing various feeds.
Square Method of Estimating Proportions
At times it is beneficial to know what proportion of
feedstuffs to combine to give a specific nutrient content,
in percent, as a mixture. For example, we may wish to add


2001.2






Example 1. This example deals with replacement heifer calves weighing 500 lb. and whose desired daily gains
are 1.10 Ib.
Total Digest-
Dry Pro- ible Vit A.
Matter tein Protein TON Ca P 1000 lU
Requirements
(Ibs.day) 12.9 1.39 0.87 7.9 .030 .025 13.1

Furnished by 11 Ib.
fescue-clover hay
(Table 1, No. 8) 9.9 1.16 .76 5.5 .085 .029 ?
Furnished by 3 Ib.
corn (Table 1, No. 25) 2.6 .27 .20 2.4 -- .009 ?

Total 12.5 1.43 .96 7.9 .085 .038 ?
Deficiencies --- --- -- -- *

*Vitamin A. should be supplemented dally In a ground cor/vltamin A mix or Injected as slow uptake material. trial.

Example 2. Wintering 1,000 Ib. Dry, Pregnant Beef Cow

Dry Total Crude Vit A.
Matter Protein Protein TDN Ca P 1000 IU
Requirements
(IbsJday) 15.1 0.87 0.42 7.6 .026 .026 16.9

Furnished by 16 Ibs.
fescue hay
(Thble 1, No. 8) 14.1 1.49 0.67 8.8 .070 .051 ?
Deficiencies -- --- -- --- --- *

Vitamin A. should be supplemented dally In a ground com/vltamin A mix or Injected as slow uptake material.


In the following example, steer calves are considered. This ration is intended as a backgrounding
ration and should produce gains of 1.7 lb. per day. The daily requirements are taken from SR-2000 and
the feedstuffs will be corn, corn silage and a complete protein supplement containing 50% crude protein.
2.5% Ca, 1.0% P and 20,000 IU vitamin A per pound. This supplement contains not more than 14% pro-
tein equivalency from urea so it is suited to growing rations.



Example 3. Backgrounding Steer Calves 600 Ib. at 1.65 lb. per day

Digest-
Daily Total ible Vit A.
Feed protein protein TDN Ca P 1000 IU
Requirements 15.8 1.76 1.13 10.1 .039 .032 16.0

Furnished by 30 lb.
corn silage
(Table 1, No. 19) 12.0 0.96 0.57 8.4 .033 .024 ?
Furnished by 3 Ib.
com (Table 1, No. 25) 2.5 .27 .20 2.4 .000 .009 ?
Furnished by 1.3 Ib.
supplement 1.2 .60 .46 .7 .033 .013 24.0

Total 15.7 1.83 1.23 11.5 .066 .046 24.0
Deficiencies -- -- --- --- --


2001.3







A different combination of feedstuffs hay, grain and supplement are used in Example 4 for a back-
grounding ration. The calves weigh 600 Ibs. and expected gains are 1.7 Ib. per day.
In this next instance a different supplement should be used. A lower protein, lower calcium, higher
vitamin A formulation is best (35% CP, 1.5% Ca, 1.0% P, 30,000 IU Vit A per pound).




Example 4: Backgrounding Steer Calves from 500-700 Ib. at 1.7 Ib. per day

Digest.
Daily Total ible Vit A.
Feed protein protein TDN Ca P 1000 IU
Requirements 15.8 1.76 1.13 10.1 .039 .032 16.0


Furnished by 11 Ib.
grass-legume hay
(Table 1, No. 9) 9.9 1.17 .76 5.5 .086 .030 ?
Furnished by
6 lb. corn 5.2 .54 .40 4.7 .001 .019 ?
'Furnished by
.3 lb..supplement .3 .10 .08 .2 .005 .003 9.0

Total 15.4 1.81 1.24 10.4 .092 .052 9.0+
Deficiencies -- -


*The availability of vitamin A from the carotene In corn and hay is uncertain. However, It would be a rare case in which
this action would be Inadequate In Vitamin A. If In doubt additional vitamin A can be supplied to the animal in salt or by
injection.





In Example 5 it is assumed the cattle average 900 Ibs during the feeding period. The supplement should contain
50% CP, 3.5% Ca, 0.7% P, and 20,000 IU Vitamin A. It could contain urea since it is being used with a high energy
ration.

Example 5: Finishing Yearling Steers, 900 Ib. at 2.9 Ib. ADG
Digest-
Daily Total ible Vit A.
Feed Protein Protein TDN Ca P 1000 IU
Requirements 22.9 2.54 1.63 16.5 .062 .051 23.0

Furnished by 15 Ib.
corn silage
(Table 1, # 19) 6.0 .48 .28 4.20 .016 .012 ?
Furnished by 15 lb.
corn (Table 1, #25) 12.9 1.35 1.00 11.85 .003 .046 ?
Furnished by 1.4 Ib.
supplement 1.26 0.70 .49 1.02 .049 .010 28.0

Total 20.16 2.53 1.77 17.07 .068 .068 28.0
Deficiencies -- -- -


2001.4






protein supplement to ground ear corn to give a 12%
protein ration. To use the square method, first make a
square as indicated in the figure below. Set in the center of

Square Method of Obtaining Proportions


Ear corn 8.1%


Supplement


38 parts






3.9 parts
41.9


the square the desired nutrient level (% protein). From the
feed composition table we obtain the % crude protein in
ear corn. If a commercial supplement is involved the feed
tag will give the % protein content. If soybean meal or
other plain protein souce is used, we can find the protein
content in the composition tables. In any case, set the %
protein in the feeds on the left side of the square. Subtract
the desired level from the feedstuff level (smaller from
greater) on the diagonal. The result is the parts of each to
combine and should be set on the left side of the square.
When these are added together and each divided by the
sum, the % of each feed in the mix is arrived at. The com-
pleted example shows 41.9 parts (91%) of ear corn is com-
bined with 3.9 parts (9%) of supplement and a ration con-
taining 12% protein results.


Ear corn % = 38 41.9 x 100 = 91% of ration
Supplement % = 3.9 41.9 x 100 = 9% of ration





































COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
Cooperative Extension Service, IFAS. University of Florida
and United States Department of Agriculture, Cooperating
K. R. Tefertiller, Director


2001.5






COMPOSITION OF FEEDS (as fed basis)


Refer- Dry Total Digest-
ence Matter Pro- Ible Cal- Phos-
Feedstuffs Number* D M tin Protein TDN clum phorus

Dry Roughages" % % % % % %
1. Alfalfa hay, mid-bloom 1-00-063 89 15.2 10.8 52 1.20 0.20
2. Alfalfa hay, early bloom 1-00-059 90 16.6 11.4 51 1.12 0.21
3. Bermudagrass hay 1-00-703 91 8.1 4.4 39 0.42 0.18
4. Bluegrass hay 89 7.0 4.2 55 0.44 0.26
5. Corncobs 1-02-782 90 2.5 .0 42 0.11 0.04
6. Cornstover 1-02-776 87 5.1 1.9 51 0.43 0.08
7. Cottonseed hulls 1-01-599 90 3.9 0.2 37 0.14 0.09
8. Fescue hay 1-01-912 88 9.3 5.3 55 0.44 0.32
9. Grass-clover hay 65%-35% 90 10.6 6.9 50 0.78 0.27
10. Lespedeza hay, mid-bloom 1-02-511 93 14.6 9.8 53 1.11 0.24
11. Oat hay, mature 1-03-280 88 8.1 3.9 54 0.23 0.21
12. Orchardgrass hay 1-03-438 88 8.6 5.1 50 0.40 0.33
13. Red clover hay 1-01-415 88 13.1 7.8 52 1.41 0.19
14. Straw, wheat 1-05-175 90 3.2 0.4 43 0.15 0.07
15. Sorghum 1-04-480 80 11.3 4.9 52 0.50 0.28
16. Timothy hay, early bloom 1-04-882 88 7.6 4.4 53 0.53 0.23
Silages **
17. Alfalfa, not wilted 3-00-212 30 5.4 3.6 17 0.49 0.12
18. Alfalfa, wilted 3-00-221 36 6.4 4.3 21 0.51 0.12
19. Corn, dent mature, well-eared 3-08-153 40 3.2 1.9 28 0.11 0.08
20. Grass-legume 3-08-144 40 6.9 4.0 22 0.45 0.10
21. Sorghum, grain variety 3-07-962 29 2.1 0.6 17 0.07 0.05
22. Sorghum-sudangrass 3-04-499 23 2.4 1.3 14 0.10 0.05
Concentrates
23. Barley 4-00-530 89 11.6 8.7 74 0.08 0.42
24. Cane Molasses 4-04-696 75 3.2 1.8 68 0.89 0.08
25. Corn, dent No. 2 4-02-871 86 9.0 6.7 79 0.02 0.31
26. Corn distillers solubles 5-02-844 93 26.9 21.0 82 0.35 1.37
27. Cows milk 5-01-168 12 3.1 3.0 16 0.11 0.08
28. Cottonseed meal 5-01-621 91 41.0 33.2 69 0.16 1.20
29. Cottonseed, whole 5-01-608 93 23.1 14.6 84 0.14 0.68
30. Dehydrated alfalfa 1-00-023 93 17.9 14.0 58 1.33 0.24
31. Ground ear corn 4-02-849 87 8.1 4.0 78 0.04 0.27
32. Milo 4-04-444 89 11.0 6.3 71 0.04 0.29
33. Oats 4-03-316 89 11.3 8.4 68 0.10 0.35
34. Soybean meal 5-04-604 89 45.8 39.0 72 0.32 0.67
35. Wheat 4-05-211 89 12.7 10.0 78 0.05 0.36
Mineral Sources
36. Dicalcium phosphate 6-01-080 96 -- -- 22.2 17.9
37. Deflourinated rock phosphate 6-01-780 100 -- 33.0 18.0
38. Ground limestone 6-02-632 100 33.8 ---
39. Sodium tripolyphosphate 96 --- 24.9
40. Steamed Bone meal 6-00-400 95 12.1 8.2 15 29.0 13.6

*Reference number is the "numerical name" of the feed from 1969 National Academy of Sciences, Publication
1684, United States-Canadian Tables of Feed Composition.
"Nutrient content of harvested forage varies greatly due to stage of harvest, and harvesting and storing conditions.
Therefore, for precision in ration balancing forage analyses should be obtained.


2001.6






COMPOSITION OF ADDITIONAL FLORIDA FEEDS (AS FED BASIS)

DRY
MATTER TOTAL DIGESTIBLE
DM PROTIEN PROTIEN TDN GA P
FEEDSTUFF % % % % % %
(RANGE) (RANGE)


DRY ROUGHAGES
Aeschynoneme2

1,2
Bahia Grass Hay,2

Bermuda Grass Hay,2

Pangola Grass Hay1'2

Peanut Hulls
1,2
Peanut Hay .2

Sugar Cane (tops fresh)
Sugar Cane (whole
plant fresh)
Bagasse2
Hemarthria Altissima. 2
Hay
1,2
Slenderstem Hay12

SILAGES
Sugar Cane Top Silage
Bermuda Grass Silage1'2

Pangola Grass Silage '

Sorghum-Silage2

CONCENTRATES
Peanuts (w/o shells)
Peanut Meal
Peanut Skins
Soybeans (seeds)
Brewers Grains (wet)
Citrus Pulp (wet)
Citrus Pulp (dried)
Citrus Molasses
Brewers Grains (dried)


85.3

90.8

91.2

87.5

91.5
91.2

25.5
27.2

91.5
84.4

90.4


29.6


12.4
(10.7-14.9)
4.3
(3.7-14.6)
8.5
(3.2-18.8)
4.9
(1.8-12.3)
6.6
8.2
(5.7-14.3)
1.3
2.0

2.7
4.7
(2.5-9.0)
4.9
(2.9-10.3)


1.5


30.4 2.6
(1.5-5.8)
32.3 2.9
(1.0-4.4)
32.6 2.1
(0.9-6.8)


94.8
89.2
94.3
90.9
23.8
18.3
90.2
67.7
91.0


28.4
45.1
17.3
37.9
5.5
1.2
6.4
5.7
25.8


7.0

0.9

4.5

4.6

3.0
4.4

0.6
1.0

0.5
0.9


0.2
1.4

1.4

1.1



23.6
40.6
12.1
34.1
4.0
0.4
2.3
2.5
19.1


42.1
(32-51)
50.8
(14-59)
48.6
(16-56)
46.8
(38-56)
16.7
39.5
(32-56)
12.1
15.7

38
45.6
(32-48)
49.2
(45-55)


15.0
16.9
(9-31)
12.8
(8-23)
16.9
(10-36)

131.1
78.2
61
83.1
15.9
15.2
76.6
52.5
60.3


0.45 0.20


0.25 0.06
1.16 0.21

0.09 0.07
0.12 0.04

0.10 0.05


0.08 0.04


0.16 0.07


0.06
0.16
0.18
0.24
0.07

2.0
1.2
0.27


0.43
0.55
0.19
0.58
0.12

0.14
0.12
0.48


SSince nutrient content of grasses depends on
zation, sample your hay (SR.5005) and get an
2Some or all of these values are from DY76-20
Program (Summary 1967-1976).


stage of
analysis.


maturity and nitrogen fertili-


Florida Forage Testing and Evaluation


2001.7





, COOPERATIVE EXTENSION SERVICE SOUTHERN STATES


SOUTHERN REGIONAL

BEEF COW-CALF HANDBOOK

SR 2002

distributedby the Institute of Food and Agricultural Sciences/University of Florida

Water for Beef Cattle'
D. G. Fox2 and O. E. Olon'


A successful livestock enterprise requires a good
water supply, in terms both of quantity and quality. While
shortage is obvious to the stockowner, he sometimes
needs the help of a laboratory in evaluating the quality of
a supply.
Water Consumption
The water requirements of cattle are influenced by a
number of physiological and environmental conditions.
These include such things as the rate and composition of
gain, pregnancy, lactation, physical activity, type of
ration, salt and dry matter intake, and environmental
temperature.
The minimum requirement of cattle for water is a re-
flection of that needed for body growth, for fetal growth
or lactation, and of that lost by excretion in the urine,
feces, or sweat or by evaporation from the lungs or skin.
Anything influencing these needs or losses will influence
the minimum requirement.
The amount of urine produced daily varies with such
things as activity of the animal, air temperature, and
water consumption, as well as with certain other factors.
The antidiuretic hormone, vasopressin, controls reab-
sorption of water from the kidney tubules and ducts, and
thus it affects urine excretion. Under conditions of re-
stricted water intake, an animal may concentrate its urine
to some extent by reabsorbing a greater amount of water
than usual. While this capacity for concentration of the
urine solutes is limited, it can reduce water, requirement
some. When an animal consumes a diet high in protein or
in salt or containing substances having diuretic effect, the
excretion of urine is increased and so is the water require-
ment.
The water lost in the feces depends largely on the diet
and the species. For instance, substances in the diet which
have a diuretic effect will increase water loss by this route,
and cattle excrete feces of a high moisture content while
sheep exercise -elatively dry teres.

'This fact sheet is adapted from GPE 1400 from the Great Plains Beef
Cow-Calf Handbook
'Extension Animal Nutritionist. Michigan State University.
'Professor, Experiment Station Biochemistry, South Dakota State
University.


The amount of water lost through evaporation from
the skin or lungs is not obvious to us, but it is important
and in some cases it may even exceed that lost in the urine.
If the environmental temperature and/or physical activi-
ty increase, water loss through evaporation and sweating
increase.
From a practical point of view, all of these factors
and their interplay make the minimum water require-
ment difficult to assess. And still another matter adds to
this difficulty. Since feeds themselves contain some water
and since the oxidation of certain nutrients in feeds pro-
duces water, not all must be provided by drinking. Feeds
such as silages, green chop or pasture are usually very
high in their moisture content while grains and hays are
low, and high energy feeds produce much metabolic water
while low energy feeds produce little. These are obvious
complications in the matter of water requirements. Fast-
ing animals or those on a low protein diet may form water
from the destruction of protein or fat, but this is of minor
significance.
Water requirements have been measured in a practi-
cal way by many investigators by determining voluntary
water intake under a variety of conditions. In brief, the re-
sults of these studies imply that thirst is.a result of need
and that animals drink to fill this need. The need results
because of an increase in the electrolyte concentration in
the body fluids which activates the thirst mechanism.
There is experimental evidence which supports this
reasoning.
As this discussion suggests, water requirements are
affected by many factors and it is impossible to list speci-
fic requirements with accuracy. However, the major in-
fluences on water intake in beef cattle on typical rations
are dry matter intake, environmental temperature, weight
and stage of production. Table 1 has been designed with
this in mind. It is a guide only, and it must be used with
considerable judgment.
Factors in Water Quality
Most ground or surface waters are satisfactory for
livestock. Some are not, however, resulting in poor per-
formance or even death in animals confined to them.
What makes water unsatisfactory for livestock? Very
oftt.a it is excessive salinity-too high a concentration of


2002.1






Table 1. Estimated Daily Water Intake of Cattle, Gallons
Mean Cows Growing Cattlo2 F;riiing Cattle
Temp. Nursing Bred, Dry 400 600 800 600 800 1000 1200
Month OF Calves' Cows & Heifers Bulls Lb. Lb. Lb. Lb. Lb. Lb. Lb.
Jan. 36 11.0 6.0 7.0 3.5 5.0 6.0 5.5 7.0 8.5 9.5
Feb. 40 11.5 6.0 8.0 4.0 5.5 6.5 6.0 7.5 9.0 10.0
Mar. 50 12.5 6.5 8.6 4.5 6.0 7.0 6.5 8.0 9.5 10.5
April 64 15.5 8.0 10.5 5.5 7.0 8.5 8.0 9.5 11.0 12.5
May 73 17.0 9.0 12.0 6.0 8.0 9.5 9.0 11.0 13.0 14.5
June 78 17.5 10.0 13.0 6.5 8.5 10.0 9.5 12.0 14.0 16.0
July 90 16.5 14.5 19.0 9.5 13.0 15.0 14.5 17.5 20.5 23.0
Aug. 88 16.5 14.0 18.0 9.0 12.0 14.0 14.0 17.0 20.0 22.5
Sept. 78 17.5 10.0 13.0 6.5 8.5 10.0 9.5 12.0 14.0 16.0
Oct. 68 16.5 8.5 11:5 5.5 7.5 9.0 8.5 10.0 12.0 14.0
Nov. 52 13.0 6.5 9.0 4.5 6.0 7.0 6.5 8.0 10.0 10.5
Dec. 38 11.0 6.0 7.5 4.0 5.0 6.0 6.0 7.0 8.5 9.5


'Cows nursing calves during first 3 to 4 months after partur
2Requirement will be a little less for wintering on range.
Table prepared by Paul Q. Guyer, University of Net

dissolved salts of various kinds. Of lesser importance is ni-
trate content, and on rare occasions alkalinity or other
factors may become involved.
Salinity. Water is a very good solvent, and all natural
waters contain dissolved substances. Most of these are in-
organic salts, the calcium, magnesium and sodium chlo-
rides, sulfates, and bicarbonates predominating. Occas-
ionally these are present in such high concentrations that
they cause harmful osmotic effects resulting in poor per-
formance, illness or even death in animals confined to
them. The various salts have slightly different effects, but
these differences are of no practical significance. Thus,
while sulfates are laxative and may cause some diarrhea,
their damage to the animal seems no greater than that of
chlorides, and magnesium salts seem no more of a prob-
lem than calcium or sodium salts. Further, the effects of
the various salts seem additive, which means that a mix-
ture of them seems to cause the same degree of harm that a
single salt at the same total concentration does.
A number of observations have been made relative to
saline livetock waters, sone of them verified, by experi-
mental findings. At high salt concentrations that are
somewhat less than toxic, increasing salinity may actual-
ly cause an increased water consumption, even when at
first the animals refuse to drink for a short period of time.
On the other hand, at very high salinities animals may re-
fuse to drink for many days, followed by a period where
they drink a large amount at one time and become sud-
denly sick or die. Older animals are more resistant to
harm from salinity than are the young. Anything causing
an increase in water consumption such as lactation, high
air temperatures, or exertion also increases the danger of
harm from saline waters. Animals do seem to have the
ability to adapt to saline water quite well, but abrupt
changes from waters of low to waters of high salts con-
centrations may cause harm while gradual changes do


milk production period.


not. Whenever an alternate source is available to them,
even every two or three days, livestock will avoid exces-
sively saline waters. And finally, when animals suffering
from the effects of saline water are allowed water from a
source of low salts content they make a rapid and com-
plete recovery.
Salt is sometimes used in feeds to regulate their in-
take. Special care to supply a drinking water of low salt
content should be taken in these instances.
A guide to the use of saline waters for livestock is pre-
sented in Table 2. Considerable judgment should be exer-
cised in using this guide. It has built into it reasonable
margins of safety, and adherence to it should prevent
deaths or economic losses with rare exceptions.
Nitrates. The poisoning of cattle by nitrates was first ob-
served prior to 1900, and there have been many cases
since. As a rule, it results from their eating forages of high
nitrate content. The nitrates are not themselves very
toxic, but in the rumen the .bacteria reduce them to ni-
trites which then get into the blood stream. There the ni-
trites convert the red pigment hemoglobin, which is re-
sponsible for carrying oxygen from the lungs to the
tissues, to a dark brown pigment, methemoglobin, which
will not carry oxygen. When this conversion is about 50%
complete, the animal shows signs of distress suggesting a
shortage of breath, and at 80% or more conversion, the
animal usually dies from a type of suffocation.
Non-ruminants may convert small amounts of in-
gested nitrate to nitrite in their intestines, but the amount
so converted is not harmful. It has been found that ni-
trates in the diet may interfere in the conversion of caro-
tene to vitamin A under some. circumstances, but an im-
pressive amount of experimental data shows this to be of
no practical significance. Further, the experimental evi- f
dence suggests that chronic nitrate poisoning does not oc-
cur in livestock and that the young are no more suscep-


2002.2







Table 2. A guide to the Use of Saline Water for Livestock and Poultry
Total dissolved solids
(milligrams/literor
parts/million)* Comments

Less than 1000 From the standpoint of its dissolved solids, this
water should be excellent for all classes of live-
stock.
1000 to 2999 This water should be satisfactory for all classes
of livestock. Those waters approaching the upper
limit may cause some watery droppings in poul-
try, but they should not adversely affect the
health or production of the birds.
3000 to 4999 This water should be satisfactory for livestock.
If not accustomed to it they may refuse to drink
it for a few days, but they will in time adapt to
it. If sulfate salts predominate, they may show
temporary diarrhea, but this should not harm
them. It is, however, a poor to unsatisfactory
water for poultry. It may cause watery feces,
and particularly near the upper limit it may
cause increased mortality and decreased growth,
especially in turkey poults.
5000 to 6999 This water can be used for livestock except
those that are pregnant or lactating, without
seriously affecting their health or productivity.
It may have some laxative effects and be refused
by the animals until they become accustomed
to it. It is unsatisfactory for poultry.


7000 to 10,000


This is a poor livestock water that should not
be used for poultry or swine. It can be used for
older, low-producing ruminants or horses that
are not pregnant or lactating with reasonable
safety.


Over 10,000 This water is considered unsatisfactory for all
classes of livestock.
'Electrical conductivity expressed in micromhos per centimeter
at 250 C can be substituted directly for total dissolved solids with-
out introducing a great error in interpretation.

tible to the acute type than are older animals. Nitrates are
occasionally found at toxic levels in water. Nitrites are
also found in water on many occasions, but not at levels
dangerous to livestock. As a rule, reports of water
analyses include nitrites with the nitrates.
Comments relating to the use of waters containing
nitrates are shown in Table 3. In using this table, it is
important to take into account the way in which the
nitrate content is expressed on the report of analysis.
Some express it in parts per million (ppm) of nitrate
nitrogen (NO3N). Others express it as parts per million of
nitrate (NO3) or of sodium nitrate (NaNO3). The rela-
tionship between these various methods of expressing it
are as follows:

1 ppm of nitrate nitrogen =4.43 ppm of nitrate or
6.07 ppm of sodium nitrate. With livestock waters
having a total dissolved solids content of less than
1000 ppm or a conductivity of less than 1400
micromhos/cm at 25 C, there is no need to make a
nitrate determination.


Table 3. A Guide to the Use of Waters Containing Nitrate for
Livestock and Poultry.
Nitrate content*
(ppm nitrate nitrogen) Comments

Less than 100**Experimental evidence to date indicates that
this water should not harm livestock or poultry.
100 to 300 This water should not by itself harm livestock
or poultry. When feeds contain nitrates, this
water could add greatly to the nitrate intake
to make it dangerous. This could be of some con-
cern in the case of cattle or sheep during drought
years and especially with waters containing
levels of nitrates that approach the upper limits.
Over 300*** This water could cause typical nitrate poisoning
in cattle and sheep, and its use for these animals
is not recommended. Because this level of ni-
trate contributes significantly to salinity and
also because experimental work with levels of
nitrate nitrogen in excess of this are meager,
the use of this water for swine, horses or poultry
should also be avoided.

'Includes nitrite nitrogen.
'Less than 443 ppm of nitrate or less than 607 ppm of sodium
nitrate.
**Over 1329 ppm of nitrate or over 1821 ppm of sodium nitrate.

Alkalinity. Many and perhaps most waters are alkaline.
This is fortunate since if they were acid they would cor-
rode pipes and plumbing. Only in a very few instances
have they been found too alkaline for livestock. Alkalini-
ty is expressed either as pH or as titratable alkalinity in
the form of bicarbonates. A pH of 7.0 is neutral, below
that is acid and above that is alkaline. Most of our waters
have pH values between 7.0 and 8.0, which means that
they are very mildly alkaline, and this further means that
they contain bicarbonates. As the pH goes up, the waters
become more alkaline, and at values of around 10, waters
are very highly alkaline and they contain carbonates.
Most waters have alkalinities of less than 500 parts per
million, and these are not harmful.
Excessive alkalinity in their water ca'n cause phy-
siological and digestive upset in livestock. The level of
alkalinity at which it begins to become troublesome and
its precise effects have not been thoroughly studied.
Therefore, the establishment of guidelines to the suit-
ability of alkaline waters for livestock is difficult.
Waters with alkalinities of less than 1000 ppm are
considered satisfactory for all classes of livestock and
poultry. Above that concentration, they are probably un-
satisfactory, although for adults they may do little harm
at concentrations less than about 2500 ppm unless car-
bonates are present in excess over bicarbonates.
Other Factors. On rare occasions, natural waters may
contain or become contaminated with certain toxic ele-
ments such as arsenic, mercury, selenium, cadmium, etc.,
or radio-active substances. While these may harm ani-
mals that drink these waters, our major concern is that
they do not accumulate in the meat, milk or eggs, making


2002.3







them unsafe for human consumption. These are analy-
zed for only when there is good reason to suspect their
presence at excessive levels.
Persistent organic pesticides have been found as con-
taminants in most surface waters. However, their con-
centration is so small in these waters (because of their low
solubility in water) that they have been found to be no
problem to livestock.
Occasionally, heavy algal growths occur in stagnant
or slow-flowing bodies of water. A few species of these
can, under some circumstances, be toxic. We have no tests
for these toxins, and at present we can only recommend
avoiding using any stagnant source of water for livestock.
While we have no meaningful laboratory methods to
measure it, filth in livestock waters must obviously be
avoided. A reasonable effort should always be made to
provide animals a clean and sanitary supply.
Miscellaneous
a. In most cases the mineral content of water should
be disregarded and mineral supplements supplied to
cattle. However, in some cases water may supply a por-
tion or all of an animal's requirement for certain minerals.
b. Hard waters have often been suggested as a cause
of urinary calculi (kidney stones or water belly). Experi-


mental evidence shows that this is not true, however, and
hardness might, in fact, actually contribute to the pre-
vention of certain types of calculi formation.
c. The results of water analyses have been expressed
in a number of ways. Some of these ways and their inter-
relation are shown below.

One part per million (ppm) means one pound per
million pounds of water. For all practical purposes,
milligrams per liter (mg/1), milligrams per kilogram
(mg/ kg), and parts per million (ppm) mean the same
thing. One grain per million is equivalent to about 17
parts per million.

d. Highly saline waters are often mistakenly refer-
red to as "alkali" waters. They may or may not be highly
alkaline, and usually they are not. Sometimes they are re-
ferred to as hard waters. If most of their salinity is in the
form of sodium salts, however, they may actually be soft
waters, as hardness is due largely to calcium and magne-
sium.
Additional Reference: Nutrients and Toxic Substances in
Water for Livestock and Poultry 1974. National Aca-
demy of Sciences, Washington, D. C.


COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acs of May 8 and Jurn 30.1914)
Copertive Extension Svice, IFAS, Univelty of Florida
and United Stat Depaerment of Aricultum, Cooperating
K. R. TfwelIler. Director


2002.4


/ I










SOUTHERN REGIONAL

BEEF COW-CALF HANDBOOK


SR2003 I

distributed by the Institute of Food and Agricultural Sciences/University of Florida

Vitamins For The Beef Herd
H. J. Gerken, Jr. and M. B. Wise, Virginia Polytechnic Institute and State University, Blacksburg, Va.


Beef cows require a minimum level of several vita-
mins to provide for body maintenance, milk production
and reproduction, and to avoid certain metabolic and
deficiency diseases. Fortunately, pasture and medium to
high quality stores roughages normally contain sufficient
quantities of vitamins to meet these needs. Also several of
the vitamins are synthesized by bacteria normally pre-
sent in the bovine rumen. Breeding cattle fed low quality
forage such as over-mature or weather-damaged hay,
crop-residue feeds, drought-stricken pasture or dry
Winter forage are more likely to require vitamin supple-
mentation.
Vitamins are classified as water soluble or fat soluble
on the basis of their chemical nature. The water-soluble
vitamins include the several B vitamins and vitamin C
while the fat soluble vitamins are vitamins A, D, E and K.
The B vitamins are seldom, if ever, deficient in practical
systems of furnishing nutrients to the brood cow. Cattle
have no dietary requirement for vitamin C which is syn-
thesized within body tissues.
Among the fat soluble vitamins, A is the one of
greatest concern, D is seldom a problem, E is almost never
deficient and K is synthesized in the digestive tract and is,
therefore, rarely of concern in cow-calf management pro-
grams. Problems of dietary insufficiency of vitamins A
and E may arise when forages are rain damaged, over-
heated in storage, or stored for long periods of time.
In the following discussion of the individual vitamins
and their role in nutrition of the beef cow herd, greatest
emphasis will be placed on those vitamins considered to
be essential. This means that the vitamin or its source or
precursor must be present in the ration either because it is
not synthesized within the animal's body or is not syn-
ethesized in sufficient quantity to supply daily needs
under specific conditions. The vitamin requirements of
the pregnant and lactating beef cow will be given primary
F consideration. Each vitamin is discussed relative to
its: (1) general characteristics and function, (2) animal
requirements, (3) deficiency symptoms, (4) sources of
supply, and (5) practical supplementation.


Vitamin A. Vitamin A is a complex 20 carbon organic
molecule that has a specific biochemical role in the pro-
cess of vision and is also required for maintenance and
normal functioning of epithelial tissues of the body
including the skin, digestive system, respiratory passages
and reproductive organs. Vitamin A is found only in
animal tissues; its precursor, carotene is found in plant
tissues. Green forages are particularly rich in carotene
which is converted to vitamin A by the animal. Beef cattle
convert 1 milligram of beta carotene to 400 International
Units (1.U.) of vitamin A. This is an average conversion
rate and may be influenced by type of caretenoid, breed of
animal, individual differences in animals, level of feed or
carotene intake and ration antioxidants. Extremely hot
weather, viral infections, altered thyroid function and
other conditions which stress cattle are thought to reduce
conversion (1).
Cattle store vitamin A and carotene in the liver and
body fat during times of abundant intake, particularly
when grazing green forages. These reserves may be large
enough to meet the metabolic needs of the cow for a
period of 3 to 4 months. This can reduce or eliminate the
need for supplemental vitamin A or carotene during
limited periods when rations deficient in carotene are fed.
An alternate possibility is that the needs of cattle for
supplemental vitamin A may be increased because of
destruction of vitamin A or carotene in feeds during
storage or even in the digestive tract. Also, intestinal
parasite and liver fluke infestations may adversely affect
carotene absorption and conversion to vitamin A.
Among the signs which may appear when vitamin A
stores are depleted and the ration is deficient are night
blindness, bulging and watery eyes, and muscle inco-
ordination. Bronchitis and coughing may appear and
progress to pneumonia. Chronic symptoms are rough
haircoat, emaciation, edema or swelling of the brisket or
forelegs. If the cow is pregnant, vitamin A deficiency may
result in abortion, weak calves that often fail to survive, or
calves that are born hairless or blind. There may be a
greater incidence of retained placentas and breeding


2003.1








efficiency in cows may be reduced. In bulls, vitamin A
deficiency may result in reduced sexual activity and sperm
production.
Fresh grazed or chopped forages contain high levels
of carotene.and stored forages which retain a portion of
their green color usually furnish sufficient vitamin A for
brood cows. Grains, straw, corn stalks and cobs, and
bleached or weathered roughage are normally a poor
source of this vitamin.
Under practical feeding conditions, several points
should be kept in mind. During drought years with pro-
longed feeding of bleached grasses or hays, body stores of
vitamin A may become low. Carotene content of dried or
sun cured forages decreases in storage. The rate of caro-
tene loss depends on temperature, exposure to air and
sunlight, and length of storage. Vitamin A losses occur
when feeds are processed with steam or pressure or when
mixed with certain minerals or organic acids. Supple-
mental vitamin A added to rations or mineral mixtures
should be in a stabilized or protected form to prevent
oxidation and rapid loss of potency.
Intramuscular injection of vitamin A palmitate into
the muscle or rumen at the rate of I million I.U.
apparently provides sufficient supplemental vitamin A to
prevent deficiency symptoms for 2 to 4 months in grow-
ing or breeding beef cattle (I). The recommended daily
requirements of vitamin A per pound ration dry matter is
1000 I.U. for growing and finishing steers and heifers,
1300 I.U. for dry pregnant cows and 1800 I.U. for breed-
ing bulls and lactating cows. When it becomes necessary
to supplement carotene deficient rations with vitamin A,
dry pregnant cows should receive up to 30,000 I.U. per
day while lactating cows and breeding bulls should re-
ceive up to 45,000 I.U. per day. New born calves of cows
suspected of being deficient in vitamin A may benefit
from an intramusclar injection of 1 million units of
vitamin A since liver stores are quite low in young calves.
Commercial preparations of injectable vitamin A may
also contain vitamin D and/ or vitamin E. The combined
products or one containing only vitamin A may be used
interchangeably to supply vitamin A. The same state-
ment can be applied to dry vitamin supplement prepara-
tions containing A, D and E which are intended for use in
mixed rations or mineral-vitamin supplement mixtures.
Commercial brood cow supplements such as forti-
fied liquid molasses supplements, range cubes or protein
blocks usually contain supplemental vitamin A. Pro-
ducers should be aware the amount of vitamin A pro-
vided by such supplements based on daily per head intake
of the supplemental feed. Farmers mixing their own beef
cow supplements should include vitamin A in the mixture
when prolonged feeding of low carotene content
roughage is a necessity. The concentration of vitamin A
should be sufficient to provide the daily levels of intake
stated above. Table I presents the daily requirements of
various sizes of beef cows for vitamin A.


TABLE I. DAILY VITAMIN A REQUIREMENTS
OF BEEF COWS


Dry, Pregnant


Lactating, Mature


Body Middle Last Average Superior
weight 3rd of 3rd of milking milking
Ibs. preg. preg. ability ability
I.U. I.U. I.U. I.U.
700-900 17000 21000 21000 34000
900-1100 20000 24000 24000 38000
1100-1300 23000 27000 27000 43000
Over 1300 25000 29000 29000 45000



Vitamin D. Absorption of calcium and phosphorus
from the digestive system and deposition of these
minerals in the bone are dependent upon the presence of
vitamin D. Beef cattle usually receive sufficient amounts
of this citamin by exposure to direct sunlight or from sun-
cured forages to meet an estimated requirement of 125
International Units (I.U.) per pound of dry ration. The
sun's radiation activates ergosterol in forage or 7-
dehydrocholesterol in the skin to produce the active
forms of the vitamin. These are designated as vitamin D2.
ergocalciferol, and vitamin D3, cholecalciferol.
Young, growing animals have a greater requirement
for vitamin D than mature animals. It should be pointed
out that vitamin D deficiency in beef cattle is relatively
rare. Whenever cases do occur, the signs of deficiency
may be preceded by a decrease in blood inorganic phos-
phorus and may include poor appetite, digestive disturb-
ances, stiffness in gait, labored breathing, arching of the
back, and erosion of joint surfaces causing pain and diffi-
culty in walking. Fractured vertebrae may result in birth
of dead, weak or deformed calves.
Only animals kept indoors and not fed sun-cured
forages are likely to develop vitamin D deficiency. Con-
sumption of 3-4 pounds of sun-cured forage daily will
supply adequate vitamin D to animals denied exposure to
direct sunlight. Commercial vitamin D preparations,
often combined with vitamin A and E, are available for
feeding or injection. Estimated requirements of vitamin D
for beef cows are presented in Table II.
Vitamin E. Vitamin E is widely distributed in the ether
extract portion of livestock feeds where it occurs as com-
plex organic alcohols known as tocopherols. Several
tocopherols have biological activity of varying potency;
the most potent form with which others are compared is
alpha-tocopherol. Vitamin E activity is measured in
International Units which are equal to milligrams of d I-
alpha tocopherol acetate. Vitamin E facilitates the
absorption and storage of vitamin A in the animal's body
by serving as an antioxidant. Muscle integrity is


2003.2








TABLE II. DAILY VITAMIN D REQUIREMENTS
OF BEEF COWS
Dry, Pregnant Lactating, Mature
Body Middle Last Average Superior
weight 3rd of 3rd of milking milking
Ibs. preg. preg. ability ability
I.U. I.U. I.U. I.U.
700-900 1600 1900 2400 2900
900-1100 1900 2200 2700 3200
1100-1300 2200 2500 3000 3500
Over 1300 2500 2800 3200 3700




dependent upon the presence of vitamin E. A number of
biochemical roles in animal cells appear to be related to
the antioxidant capability of vitamin E.
Under almost all conditions, natural feedstuffs
supply adequate quantities of vitamin E for adult cattle
and deficiency symptoms are not observed. However,
white muscle disease does occur in calves in some areas
and is due to vitamin E or selenium deficiency or both.
The requirements for beef cattle for vitamin E have not
been critically measured, however, estimates of the need
for young calves range from 7 to 27 I.U. per pound of dry
ration. Levels in this range will prevent nutritional
muscular dystrophy or white muscle disease in calves.
Signs of the disease are white muscle, heart failure
and generalized paralysis which may range in severity
from slight lameness to inability to stand. The muscle
degeneration may sometimes be observed in the tongue of
the affected calf or in a deformed or swayed back.
Ceral grains, green forage and good quality hay are
very good sources of vitamin E. Alfalfa and wheat germ
oil are especially rich natural sources of the vitamin while
active synthetic products are also available. Due to oxida-
tion, the vitamin E supply in ground feeds deteriorates
gradually. Abnormally high levels of nitrites in feeds may
lead to vitamin E deficiencies.
The trace mineral selenium and vitamin E are inter-
related. Selenium can partially replace or spare vitamin E
in the prevention or cure of white muscle disease in calves
but each is considered necessary for normal body meta-
bolism. An effective means of preventing losses of calves


from vitamin E deficiency is supplementation with alpha
tocopherol in the ration of the pregnant cow or the calf
shortly after birth. Injectable vitamin E combined with
selenium may also be administered intramuscularly to
calves in herds where white muscle disease may be a
problem. The incidence of losses from nutritional
muscular dystrophy in affected areas has been lower
among calves whose mothers received 2 or 3 pounds of
grain mixture during the last 2 months of pregnancy.
Vitamin K. .Vitamin K is synthesized in the rumen of
cattle in adequate amounts under most feeding condi-
tions and requirements have not been estimated. Vitamin
K is active in the blood clotting process where it is re-
quired for the synthesis of prothrombin, a required blood
clothing factor. Moldy sweet clover hay sometimes con-
tains high levels of a substance called dicumarol which
causes sweet clover poisoning or bleeding disease. Dicu-
marol interfers in the synthesis of prothrombin. Mild
cases of the disease may be treated by administering
vitamin K. Of course, the disease-causing hay should be
removed from the ration.
B Vitamins. This group of vitamins includes thiamin
(BI), riboflavin (B2), niacin or nicotinamide, biotin,
pantothenic acid, folic acid, vitamin B12, pyridoxine and
choline. All are water soluble. Most function as neces-
sary factors in enzyme systems in the animal body. B vita-
mins are synthesized in sufficient quantities by rumen
bacteria to meet the requirements of cattle including the
pregnant or lactating cow. Unusual feeding conditions
such as severe protein deficiency may retard rumen
fermentation enough to cause a B vitamin deficiency,
however, this kind of situation has not been demon-
strated in beef cattle production programs. Vitamin BI2
deficiency can occur when there is a cobalt deficiency in
the ration. In those areas where cobalt deficiency is
known to occur, mineral or salt supplements should con-
tain this trace mineral. Suckling calves normally receive
adequate B vitamins in milk from their dams until their
own rumen fermentation is established.


REFERENCES:
(1) National Research Council, 1976. Nutrient Require-
ments of Beef Cattle. Fifth Revised Ed. National
Academy of Sciences.


COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
Cooperative Extension Service, IFAS, University of Florida
and United States Department of Agriculture, Cooperating
K. R. Tefertiller, Director


2003.3

















distributed by the Institute of Food and Agricultural Sciences/University of Florida

Minerals For Beef Cattle
C. B. Ammerman, Professor, Department of Animal Science, Univ. of Florida, Gainesville


Minerals are an essential part of the diet of all
animals and influence the efficiency of production of beef
cattle. About five percent of the total weight of the body
consists of minerals. Certain of the mineral elements (cal-
cium, phosphorus, magnesium, potassium, sodium,
chlorine and sulfur) are required in relatively large
amounts and are often referred to as macro-minerals.
Others including iron, manganese, copper, iodine, cobalt,
zinc, and selenium are required in trace amounts. The
words "trace", "micro" or "minor" used in connection
with the latter group of minerals are not intended to
suggest a lack of importance but to indicate the relatively
small amounts present in the animal's body and required
in the ration. In certain areas, several minerals may need
S to be added as supplements to natural rations to promote
maximum performance in beef cattle. Mineral defi-
ciencies are generally "area" problems related to soil
composition and the availability of soil minerals to plants
have been given geographical locations. Gross defi-


ciencies of many elements have been observed in grazing
beef cattle but severe mineral deficiencies are usually not
seen under feedlot conditions.
Other trace minerals which may be essential include
molybdenum, fluorine, vanadium, nickel, chromium, tin,
and silicon. Deficiencies of these elements have not
appeared in domestic animals and they will not be
discussed in detail.
Mineral Requirements of Beef Cattle
Dietary mineral requirements for beef cattle, as
reported by the National Research Council (N.R.C.), 'are
shown in table 1. The values presented represent the best
estimates from available literature of the minimum
requirement for each mineral. Many nutritionists use
somewhat higher values which can be considered as
"dietary allowances" rather than requirements. The latter
values include a margin of safety. In addition, the require-
ments for certain minerals may be influenced as other
nutrients in the diet are varied.


TABLE 1 MINERAL REQUIREMENTS OF BEEF COWS
(All values expressed on a dry matter consumed basis)'


Mineral
Calcium
Phosphorus
Sodium
Chlorinec
Magnesium
Potassium
Sulfur
(PI
Iron
Manganese
Copper
Zinc
Cobalt
Iodine
Selenium
'N.R.C., Nutrient Requirements of Beef Cattle, 1976


Dry
Pregnant
Cows
0.18
0.18
0.06


0.04-0. 10d
0.6 -0.8 d
0.1 d
pm or mg per kilogram)
10 d
20

20-30d
0.05-0.10
0.05-0.10
0.05-0.10


Lactating
Cows
0.25-0.44b
0.25-0.39b
0.06


0.18
0.6 -0.8 d
0.1 d

10d
20
4d
20-30d
0.05-0.10
0.05-0.10
0.05-0.10


bHigher levels of calcium and phosphorus required for cows with greater milking ability.
'No requirement for chlorine shown. Requirement will be met by sufficient NaCI to provide sodium requirement.
dValues listed were obtained with growing and finishing steers and heifers.
'Value obtained with dry, pregnant cow.
Uligh levels of molybdenum in the forage or feed can increase the copper requirement by a factor of 3 to 5 times.


--




Deficiency Signs
Calcium and Phosphorus Calcium and phos-
phorus are the major mineral constituents of the skeleton
with some 99% of total body calcium and 80% of the total
phosphorus present in this part of the body. In addition to
their requirement by the skeleton, these elements have
many functions in soft tissues. A deficiency of either or
both causes a decrease in efficiency of animal per-
formance and severe deficiencies may result in bone
fractures. A deficiency of phosphorus also results in
reduced reproductive performance in beef cows. Phos-
phorus deficiency is observed frequently in grazing cattle
but is less of a problem in feedlot cattle. Forages tend to
be high in calcium and this element is less critical under
grazing conditions than under feedlot conditions.
Magnesium Magnesium is closely associated with
calcium and phosphorus in its distribution and metabo-
lism in the animal body. Uncomplicated magnesium defi-
ciency in beef cattle rarely occurs under normal feeding
programs. A condition in grazing cattle referred to as
"grass tetany", and by other terms, is definitely related to
abnormal magnesium metabolism and responds favor-
ably to magnesium therapy. This subject will be discussed
in detail in another fact sheet.
Potassium Experimental potassium deficiency re-
sults in growth retardation, reduced potassium level in
several body organs and pathological changes in the
heart, kidneys, and other tissues. Forages contain con-
siderable quantities of potassium and, thus, grazing cattle
are not likely to suffer from a deficiency of this element.
Extremely mature, low quality forages sometimes used in
wintering brood cows may not contain adequate levels of
potassium.
Sodium and Chlorine (Salt) Sodium and chlorine
occur mainly in the fluids and soft tissue of the animal
body. A deficiency of these elements results in a loss of
appetite and inefficient gains or loss of body weight. The
storage of sodium and chlorine in the body is limited;
consequently, there should be a regular supply of these
two elements in the diet. In most circumstances, grazing
cattle will require supplemental dietary sodium and
chlorine which are generally provided as common salt.
Sulfur Sulfur is required by the animal body in the
form of amino acids and other organic compounds rather
than in the form of inorganic sulfur. For the ruminant,
however, the rumen bacteria can utilize inorganic sulfur
to synthesize sulfur-containing amino acids. In general,
grazing cattle will receive adequate sulfur. Supplemental
sulfur may be beneficial when very mature, low-quality
forages are being grazed or fed. When non-protein
nitrogen sources such as urea are used to supply a major
portion of the nitrogen or "protein equivalent" needs of
the animal, sulfur should be included at a 12:1 ratio of
non-protein nitrogen;inorganic sulfur.
Manganese A manganese deficiency in breeding
cattle produced under experimental conditions results in
reduced fertility of cows and weak legs or pasterns in new-
born calves (figure 1). The deficiency has been reported
under grazing conditions in localized areas of certain
countries.


Figure 1. Manganese deficiency Weak legs in calffrom
dam receiving 15.8 ppm dietary manganese. (Courtesy I.
A. Dyer, Washington State University).

Zinc A zinc deficiency results in general unthrift-
iness, scabbing of the skin over the legs and loss of hair
and dermatitis over the entire body (Figure 2). Beneficial
effects from supplementing feedlot rations with zinc have
been obtained, but a consistent improvement in animal
performance with zinc supplementation has not been
shown. Supplemental zinc has increased weight gains of
cattle grazing rangeland. Based on forage zinc levels, it
appears that zinc deficiency could occur in several areas
of the world.


Figure 2. Zinc deficiency Calf on the left received ppm
dietary zinc. Note general dermatitis and scalv lesions on
legs and nose. Calf on the right received 100ppm supple-
mental zinc. The zinc deficient calfgained53 pounds in 17
weeks, while the calf receiving supplemental zinc gained
132pounds. (Courtesy E. A. Ott, W. H. Smith, and W. M.
Beeson, Purdue University).
Iodine The entire Great Lakes area and much of the
northern section of the U.S. are subject to an iodine defi-
ciency. The typical sign of an iodine deficiency in breed-
ing cattle is that of a goiterous condition seen parti-
cularly in the newborn calf (Figure 3). Although a defic-
iency of this element is seldom apparent in finishing
cattle, supplemental iodine is generally provided to feed-
lot cattle as well as to most cattle under grazing condi-
tions.


2004.2
































Figure 3. Iodine deficiency Goiter in calf resulting from
dam receiving iodine deficient diet. (Courtesy L. R.
McDowell, University of Florida).

Cobalt Cobalt deficiency signs are generally non-
specific, and frequently the animal has the appearance of
suffering from extreme starvation or from heavy parasi-
tism. Cobalt functions within the animal body as a part of
vitamin B12, which is synthesized by rumen micro-
organisms. Cobalt deficiencies are observed under
grazing conditions in certain geographical areas of the
world including sections of the United States. Positive re-
sponses to supplemental cobalt have been reported with
finishing cattle as well. Orally administered heavy pellets
made of cobalt oxide and clay which remain in the reticu-
lorumen for several months have been found effective in
supplying cobalt to cattle. The pellets are best suited for
use in areas where only cobalt is deficient or where it is by
far the most limiting deficient mineral element. In areas
where other deficiencies exist, cobalt can be supplied
along with other minerals.-
Copper Copper deficiency in cattle results in
unthriftiness, bleaching of the hair and anemia. Many
areas of the world, including Australia, New Zealand,
England, the United States and the lowlands of Europe
are subject to copper deficiency. In general, however, the
deficiency occurs under grazing conditions, with few
reports indicating problems under dry lot feeding. When
higher than usual levels of molybdenum are present in
forage, the animal's copper requirement in increased.
Iron Iron deficiency results in an unthrifty, anemic
condition in the animal. The levels of iron found in most
forages and feedstuffs in most areas of the United States
are considered adequate for cattle. Unless there are
complicating factors such as parasites, it seems unlikely


that an iron deficiency would occur in yearling or older
cattle.
Selenium A deficiency of selenium results in white
muscle disease (nutritional muscular degeneration), a
condition which occurs primarily in young calves born to
selenium deficient dams. At the present time, selenium is
not approved by the Food and Drug Administration for
inclusion in ruminant rations or mineral supplements for
ruminants. It can be given only under the supervision of a
veterinarian or obtained by using feedstuffs or feed
supplements known to be high in selenium. In selenium
deficient areas,'the use of injectable selenium-vitamin E
preparations with pregnant cows has been effective in
reducing the unthriftiness in new born calves and in
reducing the incidence of retained placentas.
Mineral Composition of Feeds
The mineral composition of several forages is given
in table 2. The composition data may be compared with
the requirement values listed in table 1, to provide a
general impression with regard to which minerals may be
present in adequate or inadequate amounts in forages.
The few examples listed indicate the considerable varia-
tion in mineral content among samples of the same type of
forage. Several surveys have indicated that the content of
trace minerals in feeds has been decreasing over the years.
Supplying Supplemental Minerals
The quantities of certain macro-minerals, phos-
phorus as an example, to be added to the diet are
generally determined as the difference between that
present in the basic dietary ingredients and the N.R.C.
requirement or other acceptable allowance. The neces-
sary amount is then provided in an inorganic supple-
mentary form. Frequently the levels of trace minerals in
the basic dietary ingredients will be ignored in formulat-
ing rations, and 50 to 100% of the N.R.C. requirement or
an accepted allowance will be added. This is done be-
cause of the tremendous variability that exists in the trace
mineral composition of feeds, the difficulty or cost
involved in obtaining accurate trace minerals at levels
which will assure adequate nutrition. The chance of iron
being deficient in a usual ration for mature cattle seems
rather remote, and supplementation with 50% of N.R.C.
requirement should be adequate. Iodine is deficient in
many areas of the United States, and zinc, manganese
copper and cobalt are known to be deficient in certain
areas of the country. Therefore, it may be desirable to
provide 100% of the requirement or allowance for these
elements, especially in areas where they are known to be
low in feedstuffs. Iodine may be added at slightly higher
levels because of its known stability in mineral mixtures.
High molybdenum in the forage can increase copper
requirement by three to five times the indicated 4 ppm.
Animal scientists within individual states will have
information concerning which mineral elements are most
likely to be deficient in their area.
In general the most satisfactory way of providing
supplemental minerals to grazing animals is through the
use of one "complete" mineral mixture (containing
macro-and trace-minerals) which is offered free-choice in
a single compartment feeder. This system requires close


2004.3





TABLE 2 MINERAL CONTENT OF FORAGES AND CORN SILAGE"


Legume orange
(992)'


Grass forage
(352)


Average Range


% dry matter basis


1.18
0.30
0.024
0.24
2.55


.03 -2.23
.14 -0.56
.001-0.10
.10 -0.58
.21 -4.93


ppm, dry matter basis


221.7
28.1
44.1
13.1


41 -800
11- 260
8 1080
2 214


"From Adams (J. Dairy Sci. 58:1538. 1975). Most of the samples originated in Pennsvlvania and
determined by emission spectrometry.
'Number of samples represented.


supervision to assure that clean, fresh minerals are avail-
able on a continuous basis and that consumption re-
mains within reasonable limits. It will probably prove
most economical to make use of commercial mineral
mixtures, although the individual may wish to prepare the
desired mineral mixture if the cattle operation is of suffi-
cient size to warrant this practice.
Mixtures containing approximately one-third to
one-half trace mineralized salt and one half to two-thirds
of a suitable feed grade calcium phosphate (usually
defluorinated phosphate or dicalcium phosphate) are
sometimes prepared on the farm or ranch for free-choice
feeding. In general, relatively small amounts of the trace
minerals ip relation to requirements will be provided by
such mixtures. Thus they are suitable for use only in areas
where it is known that no serious deficiencies of the
essential trace elements exist.
The brood cow's requirement for minerals and also
protein and energy will be highest during early lactation.
If this coincides with the winter season, protein supple-
ments in either dry or liquid form will generally be pro-
vided. Additions of phosphorus, sulfur (if non-protein
nitrogen is present) and'limited amounts of trace ele-
ments to this supplement can help meet the peak demand
for minerals.
Mineral mixtures are sometimes used as carriers for
pesticides and certain additives. An example is the ad-
ministration of larvicides for the control of flies. When
additions of this kind are made to mineral mixtures, it is
important that the normally required consumption of the
mineral is not reduced.
Determining Adequacy of a Mineral Mixture
Complete mineral mixtures offered free choice to
grazing animals should contain a minimum of 6 to 8%
phosphorus and a calcium level not to exceed two times
the level of phosphorus. They should contain 25 to 30%


New York. Values


salt unless the salt content of the cattle's drinking water is
high. An example of the amount of various minerals
supplied by a mineral mixture offered free-choice to cattle
on range or pasture is shown in table 3.
It is assumed that the consumption of the mineral
mixture will represent about 50 grams per cow daily (2
ounces equals 60 grams; 0.1 pound equals 45 grams) or
approximately 0.5% of the total dry feed intake based on
a feed consumption of 10 kilograms (22 pounds) for a 500
kilogram (1100 pound) lactating cow with average
milking ability. (The intake of 22 pounds is somewhat
high for many animals but it allows an easy approxima-
tion, on a concentration basis of minerals consumed).
Dietary requirements are listed in column 2 and the
composition of the mineral mixture is shown in column 3.
The percent of each mineral added to the animal's ration
and the percent of the dietary requirement represented by
this amount are shown in the next two columns. There-
fore, for phosphorus, the mineral supplement increased
the dietary phosphorus by .03% and supplied about 11%
of the total dietary phosphorus requirement (.28%).
Supplemental iron was supplied at a level of 50 ppm com-
pared with a minimum requirement of 10 ppm. Thus, the
supplement provided 500% of the minimum require-
ment. The use of a comparison such as this allows one to
determine fairly quickly whether meaningful levels of
minerals are being supplied by the mixture in question.
Although 50 grams orO. 1 pound (45 grams) of the mineral
mixture is a reasonable average daily consumption figure,
the intake will vary due to the type and quality of forage
or feed available.
Mineral Feeders
Feeders for providing minerals should be spaced not
farther than one-half mile apart and be adequate in
number for the maximum stocking rate of the pasture.
The feeders will be more accessible to cattle if located near


2004.4


Element


Average


Corn Silage
(7179)


Range


Calcium
Phosphorus
Sodium
Magnesium
Potassium


Iron
Zinc
Manganese
Copper


Average


Ranee


0.49
0.22
0.014
0.16
1.68


184.4
27.6
76.4
12.9


.10-1.58
.09-0.56
.00-0.11
.04-0.42
.24-4.04


32- 1200
12- 112
12-689
2 69


0.27
0.23
0.005
0.18
1.07


200.1
30.8
38.1
8.1


.01-1.88
.01-0.93
.00-0.35
.01-0.55
.02-3.28


5- 1800
3 -416
1 -267
2- 110





TABLE 3. MINERAL REQUIREMENTS AND PROPORTIONS OF THE REQUIREMENT
SUPPLIED BY A MINERAL MIXTURE CONSUMED AT THE RATE OF 0.5%
OF THE TOTAL DIETARY DRY MATTER INTAKE

Dietary Mineral mixture Supplied from 0.5%
Mineral requirementa compositionb mineral mixture

%) (%) (% of (% of
ration) requirement)

Calcium 0.28c 18.00 0.09d 2 e
Phosphorus 0.28c 6.00 0.03 11
ppm % ppm %
Iron 10 1.00 50.0 500
Zinc 30 0.25 12.5 42
Manganese 20 0.20 10.0 50
Copper 4f 0.10 5.0 125
Cobalt 0.1 0.02 1.0 1,000
Iodine 0.1 0.01 0.5 500
aN.R.C., Nutrient Requirements of Beef Cattle, 1976.
bComposition similar to certain mineral mixtures available commercially. Salt (sodium chloride) present in the mix level of 25 to 30% will
meet the sodium and chlorine requirements.
cRequirements listed for a 500 kg (1100 Ib) lactating cow with average milking ability.
dIndicates that dietary calcium was increased by 0.09% by consumption of the mineral mixture.
eIllustrates that the mineral mixtures provided 32% of the total dietary calcium requirement of 0.28%.
fHigh levels of molybdenum in the forage or feed can increase the copper requirement by a factor of 3 to 5 times.


water tanks, shaded loafing areas, and areas of best
grazing. Mineral consumption will vary due to changes in
condition of the mineral supplement. Feeders should be
checked on a weekly basis, and a clean, fresh supply of


minerals maintained at all times. Since mineral supple-
ments are corrosive to metal, the compartment for
holding minerals is usually made of wood or fiberglass. If
the mineral feeder is to be in a permanent location, the
trough can be constructed of concrete.


COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
Cooperative Extension Service, IFAS, University of Florida
and United States Department of Agriculture, Cooperating
K. R. Tefertiller, Director


2004.5







I l- COOPERATIVE EXTENSION SERVICE SOUTHERN STATES


SOUTHERN REGIONAL

BEEF COW-CALF HANDBOOK

SR-3000

distributed by the Institute of Food and Agricultural Sciences/University of Florida

Beef: Individual Identification of Cattle
Curtis Absher, Fred Thrift, and Nelson Gay, University of Kentucky


Cattle are identified primarily for two purposes: (1)
to provide positive identity for recording performance
and/ or family relationships; and (2) to serve as a means
of establishing legal title. To fulfill the first purpose, each
animal in a herd must have a unique identity; that is, it's
identification must in some way be unlike the identity of
all other animals within a herd. On the other hand, owner-
ship identity is established when each animal belonging to
an individual or firm bears the same mark of identifica-
tion.
To establish identity for record purposes, numbers,
letters or a combination are assigned to individual
animals. While individual identity is helpful in establish-
ing ownership, it is inconclusive since many animals in
, different herds can bear the same number or letter
identity. Furthermore, brand laws usually exclude the use
of letters or numbers as legal ownership marks.
A system of identification should be developed for
each herd by the owner who desires a complete record
keeping system.
The identification system should provide for the
following:
(1) Unique and positive identity for each individual.
(2) As much information about the individual as
possible at a glance. For example, Calf No. 11
could mean that this was the first calf born in
1971 while 192 would mean that this was the
19th calf born in 1972. Also, cow No. 1072 could
mean that she was the first cross, 1072, in an
upgrading system and was the 1072 calf born
in 1972. This system has been used in herds up-
grading to purebred and works well for fewer
than 100 cows.
(3) Easy recognition.

Methods of Identification

Some of the commonly used methods for individual
identification are discussed below.

1. Tattoo: An ear tattoo is required forthe registra-
) tion of most purebred animals. Tattoos are permanent
and simple to apply by the experienced herdsman. How-
ever, the main disadvantage of tattoos is that the animal
must be caught and restrained in order to identify it.


Good tattoos can be achieved if the following steps are
followed:
(I) Clean all wax and dirt from the area of the ear to
be tattooed.
(2) Set tattoo pliers to desired numerals. Check by
tattooing a piece of cardboard tattooing the ear.
(3) Firmly clamp the ear with the tattoo pliers.
(4) Rub the tattoo punctures full of ink until the bleed-
ing ceases.
A few tricks by experienced cattlemen to obtain
legible tattoos are:
(1) "You won't have a good tattoo unless your thumb
is covered with ink." However, some successful
tattoos have been made with roll-on bottles or
old toothbrushes.
(2) "Avoid the ribs in the ear."
(3) "New tattoo numerals or letters may be too sharp
to make a sufficient opening to allow an adequate
supply of ink to get under the skin." Therefore,
some cattlemen recommend "dubbing" the new
figures with a file.
2. Neck Chains or Ropes: Neck chains or ropes are
rapidly becoming an antiquated method of identifi-
cation. This method has served well up to the time of
improved techniques because neck chains are easy to
install and allow for identification without restraining the
animal. Neck chains are reasonably permanent if the
chain is kept properly adjusted and worn links are re-
placed regularly. But, some problems are associated with
the use of neck chains for individual identification of
cattle. Chains must be adjusted frequently on growing
animals and the incidence of death by strangulation due
to the entanglement of the chain is not uncommon. In
order to be completely safe, neck chains should be
equipped with "weak links" or "spring type links" that will
allow the chain to give under extreme pressure. But if this
is done, neck chains become to a degree, temporary
identification.
3. Identification tags: Tags, generally made of
plastic or light metal have been used many years as a
temporary means of individual identification. Up until
recent years, the most permanent ear tags were small and


3000.1







when placed snugly in the ears were somewhat free of
snagging. Tag manufacturers have discovered that a
principal of successful identification with tags is flexi-
bility. Manufacturers of large, easily visible tags have
used a flexible, almost rubber-like plastic or recom-
mended that the tag be installed in flexible areas, such as
near the end of the ear, in the loose skin of the dewlap, or
the flank, rather than in the ear close to the head. Tags
that have been most successful are free-swinging, flexible,
and are free of corners or projections that allow them to
become caught in fences, brush and equipment.


Figure 2: A good fire brand


Fig. 1: Ear Tagging is a convenient method ofidentifica-
tion
The most common place for installation of tags is in
the ear. However, some producers have been satisfied
with the permanency of brisket tags. Brisket tags have the
disadvantage of being difficult to read when cattle are in a
squeeze chute or grouped in a pen.
Application of numbers and figures to the tags is
important. Most tags can be purchased prenumbered, in
which case figures are embossed or bonded to the tags'
surface. Many producers prefer to number their own tags,
however. If this is done, an ink or paint that bonds with
the tag material is preferred. If a non-bonding ink is used,
tags should be numbered well in advance of their installa-
tion and then renumbered to insure permanency of the
identification figure.
Different color tags and/or ink can be used to
designate sire, herd, year or month of birth. A combina-
tion of up to four digits is easy to read and allows number-
ing of 999 calves per year with a year digit included.

4. Branding
A. Fire Branding of the hide with hot irons is one of
the oldest and most permanent techniques of es-
tablishing legal title to cattle. Also, the technique
can be. used for individual identification if num-
erals or letters are used. Fire branding is permanent
and provides a mark that can be easily recognized
at fairly great distances. The disadvantages of this
technique are: (1) a certain degree of experience
is required to make legible brands, (2) brands must
be clipped in the winter to allow complete legibi-
lity, (3) there is damage to the skin that is objection-
able to the tanning industry and (4) the technique
is considered inhumane by some people.


A few clues to good fire brands are:
(I) Use a properly heated iron. The iron is properly
heated when it looks silvery-grey in the daylight
but glows a cherry-red color when held at the bot-
tom of a 5-gallon bucket. An iron that is too hot
easily burns through the skin, while a cool iron re-
quires an extended time of application which in-
creases the chance of blotching by movement of
the animal.
(2) Restraining the animal is absolutely necessary.
(3) Irons must be properly constructed. A face width
of approximately I/4 1/2 inch is preferred and
circles of corners should be vented to prevent ex-
cessive scarring (see Figure 3 below):

VEMTS .




0345a
ZCRO IHREE FOUR FIVE RocdKINC R
Fig. 3: Branding irons should be vented to prevent
excessive scarring.

(4) Brand only dry cattle. Branding wet cattle results
in scalding and excessive scarring.
(5) Brand when flies are not a problem. Use insecti-
cide on brand if necessary to brand during fly time.
Brands should be 3-4 inches high. Hot iron
handles should be 2-1/2 to 3 feet long.
Techniques for Fire Branding:
(I) Restrain animal
(2) Heat iron as described above
(3) Select site to be branded. Shoulder, neck and thigh
marks have all been used but just behind the
shoulder on the rib cage of the hip are the pre-
ferred sites for identification numbers. The jaw is
reserved by health authorities as a site for identify-
ing diseased animals.


3000.2







(4) Clip heavy hair coats on site to be branded (This
is necessary only when hair coats are extremely
heavy or dirty.)
(5) Hold the hot iron (firmly) on the hide until the
branded area is a rich tan in color or looks like new
leather.
(6) Brands will probably need to be clipped annually
to insure legibility.
(7) Smaller, specially designed irons can be used for
fire branding the horn on horned cattle.
B. Freeze Branding of cattle with super-chilled
irons (also called cryogenic branding) has been de-
veloped in recent years with the exception of pro-
ducing hide marks that are more humane and more
easily read than fire brands. Also, it was hoped
that freeze brands would not have to be clipped,
since the hair of the branded area would be dis-
colored or white due to damage by the extreme
cold to the melanocytes (color producing cells)
of the hair.


3. Branding "irons."

4. Insulated container for coolant.

5. Alcohol (95% ethyl, methyl or isopropyl)
or acetone.

6. Dry ice or liquid nitrogen.


Figure 5: A freeze brand-summer.
I" -r


Figure 4: Freeze branding

Freeze branding has not fulfilled all of the early ex-
pectations for the technique, even though some people
have been satisfied with it. Generally, the greatest dis-
appointments have been: (1) brands still needed to be
clipped in the winter for complete legibility, (2) the pro-
cess is relatively expensive on small numbers of cattle, (3)
the visibility of the brand is not as good on yellow, white,
or red cattle as it is on black cattle.

Materials Needed for Freeze Branding:

1. Chute or restraining device.

2. Hair clippers, brush and squirt bottle.


Figure 6: A freeze brand-winter.


Technique for Freeze Branding:

Essentials of successful freeze-branding are properly
cooled irons, uniform pressure and correct timing. Key
steps follow:
1. Cool "irons" in alcohol and dry ice or liquid
nitrogen.

2. Restrain animal.

3. Clip area on fleshy part of rump or side.


3000.3







4. Clean by brushing, and wet thoroughly with
alcohol from a squirt bottle or sponge.
5. Firmly hold the iron for the necessary time.


Calves


Alcohol and dry ice 40 seconds
Liquid nitrogen 10-15 seconds


r


Mature cattle
60 seconds
20-30 seconds


C. Chemical Branding is done by applying a
caustic liquid or paste to the hide with a specially
designed iron. The chemical causes irritation to the
skin, removal of the hair and a scar to form. While
a minimum amount of skill and equipment is re-
quired for this method, ideal weather is necessary
and smearing of the chemical by riding or tail
switching must be avoided. Results with chemical
branding have been highly varied. If this technique
is chosen, directions supplied by the manufacturer
of the chemical should be closely followed.
Angle Brand System
A universal identification system, based on two
concentric squares, has been devised by U.S.D.A.
ARS workers. In the basic square, numbering starts
with 2 and continues clockwise 4, 6, 8. Odd numbers
are shown by a second square, rotated an eighth
turn to the right as shown in figure 7.
These marks can be applied by either hot or cold
branding techniques. In recognition trials these were
more easily read than numbers.


= 1
"--"


71



6-


SI L is read 1048.

Figure 7: Angle brand system.

Summary
Identification is a must in modern beef production.
A good identification system may combine two or more
methods, such as ear tags and tattoos for individual
identification and fire or cold branding for establishing
ownership. One simple principle of identification that is
frequently violated is that every time a number is changed
on an animal the chance of a record mix-up is increased.
Where possible, numbers on brands, tags, tattoos and
neck chains should correspond, and once an animal is
assigned a number, that should be his for life.


COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
Cooperative Extension Service, IFAS, University of Florida
and United States Department of Agriculture, Cooperating
K. R. Tefertiller, Director


3000.4


Timing




. COOPERATIVE EXTENSION SERVICE SOUTHERN STATES M


/ SOUTHERN REGIONAL

BEEF COW-CALF HANDBOOK

i SR 3001

distributed by the Institute of Food and Agricultural Sciences/University of Florida


Management of the Beef Cow

at Calving Time(Prior, During and After)

Fred C. Powell, Associate Professor, and, Haley M. Jamison, Professor & Leader,
Animal Science-Beef Extension, University of Tennessee


The beef cow is the most important single link in the
beef production chain. All advantages gained by genetic
selection for such desirable economic traits as growth
rate, feed efficiency and carcass value are lost unless the
beef cow produces and weans a healthy calf.
Approximately 15 percent of the Southeastern beef
cow herd fails to wean a calf on an annual basis. Roughly
one-half of this loss is due to conception failure with most
of the other one-half being lost at calving time or shortly
thereafter. Losses at calving time can be further classified
as roughly one-half occurring with first-calf heifers and
one-fourth with second-calf heifers. The remaining one-
fourth of calving loss occurs in mature cows four years of
age or older.
Experienced beef cow herd managers maintain that
one-half of the losses at calving time can be prevented by
prompt application of recommended management
practices. This indicates that the annual calf crop could be
increased at least four percent by improving manage-
ment at calving time. Since most calving losses occur with
first and second-calf heifers, this age group might well be
singled out for special attention.
The calving period is a critical stage for the beef cow.
This is particularly true for the first-calf heifer since she is
undergoing this severe stress experience for the first time.
Even for older cows, this is the greatest stress period of the
year. As calving time approaches, the cow becomes
nervous and is more susceptible to other environmental
stresses such as unfamiliar sights or sounds. Avoiding un-
necessary stresses is an excellent beginning for a success-
ful calving period. Keeping the cow herd comfortable and
in familiar surroundings will reduce potential stress
problems.
Prior To Calving
During the last 30-45 days of pregnancy, the cow
herd will generally need a 10-15 percent increase in the
ration if being fed stored roughages. This can be in the
form of an extra 2 pounds of hay or hay equivalent in
order to furnish an additional pound of TDN (Total


Digestible Nutrients). Ration quality can be improved at
the same time by slightly increasing the protein level. For
example, the extra 2 pounds of hay might be legume or a
legume-grass mixture. Other methods of increasing the
protein level might include protein blocks, liquid supple-
ments, range cubes, protein-salt mixes, or grazing small
grain pastures for 4-5 hours once every 4-5 days. If the
cow herd has been wintered on accumulated permanent
pasture growth such as fescue, legume-grass hay or silage
properly supplemented, the ration should need little if any
supplemental protein. The 10-15 percent increase in
quantity will take care of the additional requirements of
the unborn fetus. Forage testing can be helpful in match-
ing available feed supply to specific cattle needs.
Location of a calving site is important for ease of ob-
servation. A small, clean, heavily sodded pasture best
serves this purpose from the standpoint of sanitation and
disease prevention. This also permits the cow to calve
under natural environmental conditions rather than
being restricted to a stall, shed or pen. Avoid muddy lots,
open water supply areas and crowded enclosures.
Separate heavy "springers" from the herd and move
them to the selected calving site several days (5-10) in ad-
vance of the calving period. This makes frequent observa-
tion an easier task and also permits the cows to accustom
themselves to the slight change in their environment. The
cows closest to calving can sometimes be recognized by
sunken flanks, distended abdomen, swollen vulva and
enlarged udder.
Constant observation of "close-up" cows is unneces-
sary. Casual observation at 3-4 hour intervals is generally
adequate to detect calving difficulties. First calf heifers re-
quire more frequent observation than mature cows.
During Calving
As the beef cow approaches parturition she becomes
nervous and restless. Labor pain begins a few hours
before birth and increases in both frequency and inten-
sity until the act of calving is performed. The cow
becomes more restless and feverish due to stress inten-


3001.1







sity. Most cows will attempt to calve in seclusion away
from both man and other animals if they have a choice.
The beef cow will normally calve in a 1-3 hour
period. If calving proceeds normally, the cow should be
left alone. Actual birth is first indicated by appearance of
the fetal membrances and breaking of the water bag
which has been the embryonic home of the calf during the
gestation period. This stage is soon followed by ap-
pearance of the calf. A normal presentation is both front
feet first with the head on the knees.
After Calving
The time immediately after the calf hits the ground is
critical. If delivery has been normal, few problems will be
encountered. A quick examination to determine if the calf
is breathing is about all that is necessary. If the nostrils are
covered with fetal membrances or filled with mucous
fluid, these obstructions should be quickly removed.
Initial breathing can often be induced by blowing into the
calfs nostrils, applying pressure to the chest areas (arti-
ficial respiration) or using a straw to tickle inside the
nostril causing sneezing or coughing.
Within 30-45 minutes after birth the calf should
stand and nurse. If weak or chilled, the new calf should be
rubbed briskly with a dry cloth or burlap bag to speed up
circulation and helped to stand and nurse. Getting the
colostrum or first milk from the cow into the calf is
important. This first milk is highly concentrated in food
nutrients suited to the young calfs digestive system. In
addition, this first milk contains antibodies that are help-
ful in prevention of young calf diseases, particularly of the
digestive system. Dipping the umbilical or navel cord of
the young calf into a disinfectant solution is recom-
mended as a means of preventing infection.
Once a young calf is claimed by the cow, standing


and nursing, most problems of calf loss at birth have been
eliminated. Many early calf losses after this are due to
scours which are undetected and untreated or do not
respond to treatment. Calf scours may be nutritional (too
much milk), bacterial (dirt or filth) or viral. Each type of
scours may require a different treatment. If scouring is
common in the calf crop, a veterinarian may be needed for
diagnosis and treatment.
After calving, the cow needs only rest and quiet for
the first day along with access to water. Her need for extra
feed above the gestation ration will need to be met when
the calf has reached 2-3 weeks of age. This need can be met
by increasing the gestation ration by 50-60 percent. If
roughly one-third of the hay ration is legume or a legume-
grass mixture, the ration requirements will be met.
Rations consisting primarily of grass hay or silage will re-
quire protein supplementation at the rate of I to 1-1/2
pounds of 40-45 percent crude protein per day.
The cow should "clean-off" by expelling the fetal
membranes or afterbirth remaining in her reproductive
tract. If this final stage of parturition has not taken place
within 24 hours, steps should be taken to insure that the
action does occur. These steps may involve either
manually removing the afterbirth or administering
hormonal injections to speed up expulsion. A retained
afterbirth putrefies rapidly and can result in toxemia
(blood poisoning) causing a delay in the rebreeding sche-
dule or the cow becoming a non-breeder.
In order to rebreed on schedule (within 80-85 days
after calving), the brood cow must recover from calving
stress, repair her reproductive tract, furnish milk for her
growing calf and start cycling. She can meet these require-
ments only if free of disease and parasites and her nutri-
tional requirements have been met.


COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
Cooperative Extension Service, IFAS, University of Florida
and United States Department of Agriculture, Cooperating
K. R. Tefertiller, Director


3001.2




S COOPERATIVE EXTENSION SERVICE SOUTHERN STATES -


SOUTHERN REGIONAL

BEEF COW-CALF HANDBOOK

SR 3002

distributed by the Institute of Food and Agricultural Sciences/University of Florida

Management of the

Commercial Cow-Calf Herd

for High Calf Crop Percentage
James B. Neel, Assistant Professor, Animal Science Extension-Beef, University of Tennessee


Percent calf crop weaned is the single most
important factor that influences returns from a cow-calf
operation. Percent calf crop should be defined as the ratio
of calves weaned to all females in the herd that were
exposed to a bull during the breeding season. Table I
shows that as percent calf crop increases, pound of calf
and profit per cow increase along with a decrease in
production cost per hundred pounds of calf weaned.

TABLE I
The Influence of Calf Crop Percentage on Pounds
of Beef Produced Per Cow and Production Costs
at Various Weaning Weightsa


Calf Crop Weaning Weight (lb.)
Percentage 500 450 400 350
100 500b 450 400 350
$25.20c $28.00 $31.50 $36.00
95 475 428 380 332
$26.53 $29.44 $33.16 $37.95
90 450 405 360 315
$28.00 $31.11 $35.00 $40.00
85 425 382 306 298
$29.64 $32.98 $41.18 $42.28

a $126.00 variable annual costs were assumed.
b Top figures in each row represent pounds of beef produced
per cow for each weaning weight and calf crop percentage.
Pounds of beef produced per cow was calculated by multiply-
ing average weaning weight by percent calf crop.
c Bottom figures in each row represent cost per cwt. of calf pro-
duced. Production cost per cwt. was calculated by dividing
annual cow costs by pounds of beef produced per cow.
Not only does a low calf crop percentage have an
adverse effect on returns, but it also reduces the number
of animals available for selection and thereby could


reduce the amount of genetic progress that might be
made.
Calf crop percentage varies widely throughout the
South. The Southern Beef Industry has made outstand-
ing progress in improving individual animal per-
formance traits. However, corresponding gains in repro-
ductive efficiency have not been realized despite the tre-
mendous importance of calf crop percentage on returns to
a cow-calf operation.
Calf crop percentage is affected more by manage-
ment than individual animal performance traits. Perhaps
one of the problems in improving management and
consequently calf crop percentage is that the decisions
carried out during the current year will not be known until
12 to 15 months later and more than likely will not be fully
realized until years hence. For this reason, some pro-
ducers may become discouraged and slow to make
improvements in management.
Failure of beef females to become pregnant and
losses during calving are the leading causes of poor calf
crop percentages. With increasing production costs, the
cow-calf producer must make an intensive effort to
reduce losses in both of these areas if profits are to be
realized.
The following discussion briefly outlines basic
management practices that will contribute to both
increased calf crop percentage and returns.
Select Older, Heavier Heifers For Replacements
Heifers that are heavier and older at the onset of the
breeding season will usually experience greater calving
percentage than younger, lighter weight heifers. Occur-
rence of puberty (sexual maturity) is a function of weight
and age. Most English Breed heifers reach sexual
maturity at about 600-650 lb.
One of the biggest problems in breeding heifers is
that they might be either too light or too young to breed
earlier than or with the cow herd. This results in a
reduction of the conception rate and the number of calves
at weaning. Some of the lighter weight heifers will breed;


3002.1






however, calving problems can be expected.
Weight should not be confused with "fat" which has
an adverse effect on future reproductive performance. See
SR 1000 for more information on selection of replace-
ments.
Select Replacement Heifers Based on Reproductive
Performance
Select replacement females from the older group of
heifers in the calf crop and from dams that have had a
history of regular calving. Approximately 50 percent
more heifers than are needed for replacements should be
selected; expose the heifers to a bull for 60 to 70 days; and
then cull all open heifers. Another culling and final selec-
tion should be made following the second breeding
season.
Give Replacement Heifers Proper Winter Care
Following selection at weaning, replacement heifers
should be separated from the other cattle and be managed
to gain 1.0 to 1.25 lb. per day or weigh 650 to 700 lb. at
breeding. Heifers wintered at a greater rate of gain will ex-
perience decreased lifetime reproductive efficiency. This
is why it would be to the producer's advantage to select
heavier, older heifers at weaning. Younger, lighter weight
heifers would have to be wintered at a faster rate of gain to
weigh 650 to 700 lb. at breeding.
Breed Heifers Approximately Thirty Days Before The
Mature Cow Herd
First calf heifers tend to breed back slower than
mature cows during their second breeding season. Several
factors contribute to delayed conception: the heifers are
still growing, starting lactation, recovering from the stress
of calving, and getting their reproduction tract back in
shape. By breeding heifers 30 days before the mature cow
herd, this extra month allows added time after calving to
build their body up and will be on the same breeding and
calving schedule as the mature herd. This also provides an
opportunity for the heifers to receive extra attention
during calving.
Breed First Calf Heifers To Bulls That Produce Calves
With Small Birth Weights
Calving problems with first calf heifers can be re-
duced by breeding heifers to bulls that have a known per-
formance of siring calves which were lighter in weight at
birth. This does not advocate a certain breed, size or age
of the bull. There is no validity to the old belief that a
young bull will sire smaller calves.
Do not breed heifers to a large, heavy muscled, thick
shouldered bull or a bull with excessively large rear-
quarters.
Separate Heifers Calving as 2 Year Olds From Mature
Cow Herd and Winter Separately
Heifers calving as 2 year olds will probably be
"bossed" by older, mature cows and not receive their fair
share of feed. These heifers need adequate feed to conti-
nue their growth and to meet the nutrient requirements of


the unborn calf. Most calving problems occur with light-
weight, weak heifers. Separating these young heifers and
providing them the necessary feed to assure growth and
development will help to reduce these problems.
Provide Adequate Nutrition Prior to Calving and During
the Breeding Season
The nutritional intake of the beef female 45 to 60
days prior to and 90 days following calving is the most
critical factor in the brood cow's 365 days production
cycle from a reproductive and energy requirement stand-
point. Dry, pregnant mature beef cows' energy require-
ment can be adequately met by providing about 8 lb. of
TDN intake per day up to about 45 to 60 days prior to
calving. See SR 2000 for more information on nutrient
requirements of beef cows. During these last 45 to 60 days
of gestation, the TDN level should be increased to 9 lb.
per day. Following calving, the TDN requirements in-
crease up to about 16 lb. of TDN per day.
Inadequate TDN levels prior to calving will result in
an increase in the number of days it takes for the cow to
come into heat following calving; whereas, insufficient
TDN following calving results in an increase in the
number of services per conception.
The big factor to remember is that inadequate nutri-
tion will result in delayed rebreeding and consequently
later calving dates and decreased calf crop percentage.
Provide Adequate "Bull-Power" To The Cow Herd
During The Breeding Season
Adequate "bull-power" can be defined as the cap-
ability of the herd sire to mate with and settle cows during
a fertile heat period at the proper time during the breed-
ing season. Bull-power would be influenced by the age
and condition of the bull, semen quality, abnormalities of
the bull's reproductive tract, reproductive diseases,
skeletal weakness and the number of cows allotted per
bull.
Bulls should be in a good condition, not fat, prior to
onset of the breeding season. Young, growing bulls may
need to be provided extra feed during the breeding season
to meet their protein and energy requirement. Generally,
good pasture will adequately meet the bull's nutritional
needs.
Bulls should be purchased no later than 40 to 60 days
prior to the breeding season. This will allow ample time
for the bull to overcome any stress that might have
occurred during sale or transportation and to adjust to his
new environment.
Examination of the bull's reproductive tract and
semen evaluation should be made each year, 15 to 20 days
prior to onset of the breeding season. This may identify
problems that might reduce fertility and allowample time
to make corrections without losing a whole calf crop or
having late calves.
Condition of the bull's feet and legs is as important as
his reproductive capability. Bulls with feet and leg
problems will not be able to locate and mate with cows in


3002.2


I'






heat. A missed mating will result in either a late calf next
season or an open cow at the end of the breeding season.
Yearling bulls should be assigned 12 to 15 cows and
mature bulls about 25 to 30.
See SR 3003 for more information on management
of herd bulls.
Cows Should be Allowed Adequate Rest Following
Calving Before Exposure to a Bull
Cows that are exposed to a bull less than 45 to 50
days following calving will probably experience de-
creased conception rates. Cows need a period of rest to get
their reproductive tract back in shape and clear up any
infections that might be present.
Observe the Cow Herd Frequently During the Breeding
Season
The cow herd should be checked regularly during the
breeding season. Watch the bulls closely to make sure
they are finding cows in heat and mating with them.
Record breeding dates and observe these cows carefully
16 to 22 days later for return heat. If the percentage of
repeat breeders is high, check for factors that may inter-
fere with conception.
Develop a Definite Breeding and Calving Season
The season or time of year that calves are born will
have an influence on calf crop percentage. The limited re-
search on this subject suggests that cows calving during
the winter and early spring in the Southeast tend to wean
S a higher percent calf crop.
The beef brood cow has the need for a high level of
energy during breeding to achieve satisfactory concep-
tion rates. Pasture availability and consequently energy is
normally at its highest during the spring and lowest
during late fall and winter. As a result, conception rates
are the highest in the spring, which is the time when winter
and early spring dropped calves are conceived, and lowest
in the late fall and winter. Observations by cattlemen and
research have indicated that cows start cycling and are
settled when green grazing comes in the spring. The exact
date when grass becomes available would vary through-
out the Southeast.
There are other environmental conditions, such as
temperature and humidity, that occur during the spring
that are also favorable to improved fertility in both the
bull and cows.
Another factor to consider in developing and
planning a definite calving season would be the labor
available to observe the cows and provide assistance if
needed during calving.
With a definite calving season, slow breeders and
open cows could also be identified and culled which
would result in an increased calf crop percentage.
When all factors are considered, conditions are more
favorable for a greater calf crop percentage when the cows
are bred in the spring and early summer to calve in the late
winter and early spring.


Check the Cow Herd 3 to 4 Times Daily During the
Calving Season
The majority of calf losses during calving is due to
abnormal presentations and delayed or difficult de-
liveries. A very high percentage of these calf losses could
be prevented by being "close at hand" and providing aid
in difficult births. Calving problems occur in cows of all
ages; however, most problems occur in first calf heifers. If
possible, first-calf heifers should be located in pastures
that are easily accessible for frequent observations.
See SR 3001 for more information concerning
management of the cow herd during calving.
Pregnancy-Check and Cull the Open and Slow Breeders
Cow-calf producers should set the goal of a calf every
12 months from each cow. A cow must produce a calf
every 12 months to pay for her upkeep. Approximately 65
to 70 percent of the slow breeders or nonbreeders fail to
conceive even when exposed for a longer period of time.
Cows should be pregnancy checked about 4-5
months after the onset of the breeding season. Open cows
should be marketed before they lose weight and condi-
tion.
Most veterinarians, artificial insemination techni-
cians and some experienced cattlemen may be able to
carry out pregnancy checks. The cost for the service is
minimal when the expense of carrying an open cow for a
year is considered.
Develop and Utilize Adequate Working Facilities
Adequate corrals, chutes and headgates are essential
for carrying out necessary management practices, such as
vaccinating, pregnancy checking, branding and sorting.
Working facilities need not be expensive or elaborate but
should be designed and constructed to work efficiently
and fit the needs of the herd.
Develop and Utilize An Effective Identification and
Record Keeping System
Good herd management cannot be realized without
an identification and record system. In fact, most of the
management practices outlined in this discussion could
not be carried out without records. Keep the records that
will help in identifying problems and making manage-
ment decisions. These records should include calving
care, calving dates, heat periods and breeding dates.
These records should be used when culling cows, select-
ing replacement heifers, selecting bulls and planning
breeding groups. Keep records simple and workable.
Develop a Complete Herd Health Program
Diseases often contribute to decreased calf crop per-
centage. These may be divided into categories; those that
affect reproduction and those that produce calf losses be-
tween birth and weaning.
Reproductive diseases may cause abortions, sterility,
birth of weak calves and breeding difficulties. These dis-
eases would include Brucellosis, Leptospirosis, Vibri-
osis, Trichomoniasis and Vaginitis. Further information


3002.3




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