Proceedings of the twelfth annual...
 Table of Contents
 Fly control for the future
 Growth implants for beef cattl...
 Proper implant care and use
 Libido testing of bulls
 CBDU herd health calendar
 CBDU management calendar

Group Title: Quincy NFREC research report ;
Title: Chipley B.D.U. field day
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00095187/00001
 Material Information
Title: Chipley B.D.U. field day Chipley Agricultural Center and Beef Demonstration Unit twelfth annual meeting, Chipley, Florida, Wednesday, Aprill 9, 1986
Series Title: Quincy NFREC research report ;
Alternate Title: Proceedings of the Twelfth Annual Chipley Beef Demonstration Unit Field Day
Chipley Beef Demonstration Unit field day
Physical Description: ii, 32 p. : ill. ; 28 cm.
Language: English
Creator: North Florida Research and Education Center (Quincy, Fla.)
North Florida Research and Education Center (Quincy, Fla.)
Publisher: North Florida Experiment Station
Place of Publication: Quincy Fla
Quincy Fla
Publication Date: 1986
Copyright Date: 1986
Subject: Beef cattle -- Florida   ( lcsh )
Beef cattle -- Breeding -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
Bibliography: Includes bibliographical references (p. 27).
General Note: Cover title.
 Record Information
Bibliographic ID: UF00095187
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 - 173684045

Table of Contents
    Proceedings of the twelfth annual Chipley beef demonstration unit field day
        Page i
        Page ii
    Table of Contents
        Page iii
        Page iv
    Fly control for the future
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
    Growth implants for beef cattle
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
    Proper implant care and use
        Page 20
        Page 21
    Libido testing of bulls
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
    CBDU herd health calendar
        Page 28
    CBDU management calendar
        Page 29
        Page 30
        Page 31
        Page 32
Full Text



The Chipley Beef Demonstration Unit is an on-going commercial

cattle operation sponsored by the University of Florida Cooperative

Extension Service. The principal function of the unit is to demon-

strate comprehensive livestock-forage systems applicable for North-

west Florida beef producers. The unit also serves as an educational

center to instruct individuals in daily livestock management practices.

This is accomplished through field days, clinics, farm demonstrations

and individual visitation by producers. The unit is open to the

public weekly and dates of specific demonstrations can be obtained

from your local County Extension Director.

David L. Prichard
Extension Livestock

1986 Program Participants

Mrs. Shirley Clark, Extension Home Economist, Quincy, Florida

Mr. Jim Clemmons, Farm Manager, CBDU, Chipley, Florida

Dr. J. A. Hogsette, Jr., USDA Research Entomologist, Panama City,

Dr. R. E. Larsen, Research Veterinarian, University of Florida,

Dr. F. W. Leak, Extension Meat Specialist, University of Florida,

Mrs. Lizette Murphy, Consumer Food Marketing Specialist, University
of Florida, Gainesville

Dr. D. L. Prichard, Extension Livestock Specialist, University of
Florida, NFREC Quincy



1. Fly Control For The Future

J. A. Hogsette, Jr.....................................

2. Growth Implants For Beef Cattle

D. L. Prichard .....................................

3. Proper Implant Care And Use

D. L. Prichard................................... ....

4. Libido Testing Of Bulls

R. E. Larsen ........................................

5. CDBU Herd Health Calendar...................................

6. CBDU Management Calendar....................................


Fly Control for the Future


J. A. Hogsette

USDA Research Entomologist
Panama City, Florida

The horn fly, Haematobia irritans (L.), and the stable fly, Stomoxys

calcitrans (L.), are the 2 most important economic pests of cattle in

Florida. Both flies feed by sucking blood from cattle, and large pop-

ulations of either species can cause a reduction in weight gains and

milk production, and an unthrifty appearance.

The horn fly is about half the size of a house fly, and is the fly

most commonly noticed by livestock owners since it spends most of its life

on the cattle. Except for occasional movement from cow to cow, horn flies

rarely leave the animals except to lay eggs in manure that has been on the

ground less than 10 minutes. Horn flies can usually be found on the backs,

sides, undersides, and lower legs of cattle when populations are moderate

(50 to 100 flies per cow). When populations are heavy, flies may move onto

cows' necks and heads. The economic threshold level (the number of horn

flies a cow can support before weight gains, etc. are reduced) is 50 horn

flies per cow (Butler 1975). Populations of 300 or more per animal are not

uncommon during the summer months.

The bite of the horn fly is painful and large populations of feeding

flies will cause cattle to become restless. Cattle with actively-feeding

horn fly populations can be seen swinging their tails over their backs

and throwing their heads repeatedly over one shoulder and then the other

in an effort to dislodge the flies.

The immature stages of the horn fly develop in the manure where the

eggs are laid. Larvae, or maggots, hatch from the eggs in about 18-24

hours and complete their 3-stage developmental cycle in about 7 days.

Next the larvae enter the pupal stage and are encased in a capsule-like

structure called the puparium. About seven days later, the flies will

emerge from the puparium in the adult form. Adults mate when they are 3

to 5 days old and females begin laying eggs shortly thereafter. The life

span for adults is probably about 2 weeks under field conditions.

The stable fly is about the same size as, and commonly mistaken for

the house fly. When house flies alight on cattle they seldom stay in one

place unless they are feeding on moisture around the eyes or on the hair.

In contrast, once stable flies alight, they stay in one place, usually on

the lower legs, and attempt to take a blood meal. Cattle annoyed by stable

flies will stomp their feet and swing their tails low in an effort to pre-

vent the painful bites inflicted by the flies. Flies will continue to

feed, in between foot stomps and tail swishes if necessary, until they

are fully engorged with blood. Only then will they leave the cattle and

fly to a nearby resting site, such as a.fence, tree, or wall, to digest

their meal. Since each stable fly does not feed during the same time

period, only a percentage of the population is on a herd at any particular

time. In fact, it has been estimated that for every stable fly observed

on a cow, 50 are resting in the environment. This staggered feeding be-

havior plus the problem with mistaken identity often lead a producer to

underestimate the extent of the stable fly infestation on his herd. The

economic threshold is 5 stable flies per cow (Steelman 1976).

Stable flies prefer to lay their eggs in actively decomposing veg-

etative materials such as hay, feed, silage, and green chop. Manure

will be used if it is available and conditions are right.

The life cycle and developmental stages are approximately the same for

the stable fly and the horn fly. Stable fly adults probably live 7

to 10 days in the field.

The stable fly is noted as a strong flier with established flight

range of 135 miles. Local movement of 5 miles or more has been recorded

routinely in the agricultural area of NW Florida for several years.

Large numbers of stable flies can suddenly appear on farms where no flies

are being produced. With this degree of mobility, stable flies can re-

produce in suitable materials such as hay, feed, and silage that are long

distances from livestock. In conclusion, the flight ability of the stable

fly can make it a difficult pest to control.

Control techniques, until recently, consisted mainly of insecticidal

liquids that were applied with a sprayer, or insecticidal liquids and

dusts that the animals self-applied via backrubbers, oilers, and dust-

bags. In the early 1980's, however, a new self-application device came on

the market: the cattle ear tag. This new device was going to take the

labor out of horn fly control. In experimental trials in the late 1970's,

certain tags applied at the rate of 1 per animal completely eliminated

horn flies, stable flies and to some extent house flies and horse flies

for up to 6 months. One tagged animal in a herd was enough to kill all

of the horn flies on the entire herd for several months. Some researchers

found that by tagging only the bulls, which are particularly attractive to

horn flies, flies on the entire herd would be controlled. Today, two

tags per animal will not kill the first horn fly in many regions of the

Southeastern US. Why are these ear tags no longer effective? Have the

chemical companies changed the tags in some way or have they stopped

putting any pesticide in them?

The reason the tags no longer kill horn flies is that the horn

flies, not the tags, have changed. The horn flies have become resistant

to the pesticides used in the tags. This is the same problem that oc-

curred with DDT and the house fly in the early 1950's. Once an insect be-

comes resistant to a pesticide, the pesticide can no longer be used to

control the insect. Even worse, by building resistance to one pesticide,

an insect can more quickly develop resistance to other pesticides hav-

ing similar chemical structures. Can you imagine what it would be like

if all of our pesticides were rendered useless because of resistance?

Resistance is something we all hear about from time to time, but

it may not be quite clear to some of us just what resistance is. Before

we discuss resistance, however, we must first say a word about tolerance.

When the recommended amount of pesticide will no longer kill the pest

insect, but the recommended amount plus a little more will, that is a

sign that the pest insect is building a tolerance to the pesticide. The

more often you use the pesticide, the more and more of it you will have

to use to kill the pest insect. As this gap, or tolerance level, be-

tween the amount of pesticide recommended for useand the actual amount

you have to use widens, it is finally referred to as the resistance level.

If the resistance level continues to increase, it will reach a point where

the pest insect is no longer affected by the pesticide even if applied

full strength.

How does the insect do this? Unlike humans or cattle, flies pro-

duce hundreds of offspring each week. This allows for the creation of

flies with unlimited combinations of genetic characteristics. The genotype

for physical appearance is pretty much fixed; that is, all horn flies

look very similar. However, the genetics for internal chemical systems

can be quite variable. Exposing horn flies to a herd of cattle that has

ear tags giving off a daily dose of pesticide at a fixed level for a long

period of time might be compared to putting the horn flies in a large

screen cage with one small hole in it. Many flies will die, but sooner

or later, one fly will by chance come upon the hole and fly through it

to freedom. Many flies will die with the ear tags too, but sooner or

later, one fly will be produced quite by chance that has a combination

of genetic characteristics which will enable that fly to detoxify the

pesticide used in the ear tags. This fly will survive. If this fly

is a female, a percentage of her offspring will also have this ability.

If it is a male, the ability will be transferred to the females (more

than 1) he mates with, and a percentage of their offspring will also

have the ability to detoxify the ear tag pesticide. These offspring,

which are produced in a mere 2 weeks, soon reproduce and very quickly

make up a large percentage of the horn fly population on the herd

simply because horn flies that cannot detoxify the pesticide are being

killed by it.

When pyrethroid-impregnated ear tags were first introduced, the

activity of the pesticide was overwhelming. All horn flies on a herd

were dead by the time the last tag was applied. But after a year or two,

tags that were originally effective for 6 months were only effective for

4 or 5 months. Increased tolerance levels were building. Continued

use of the ear tags soon resulted in the development of resistance to

pyrethroids by horn flies. At certain test sites near Chipley (in Jackson,

Washington, and Holmes counties), resistance developed in 12 to 18 months.

At the Beef Demonstration Unit in Chipley, where a variety of pyrethroid-

impregnated ear tags have been tested, the last time an ear tag provided

even a slight degree of horn fly control was in the fall of 1983. Stable

flies have not become resistant to ear tags, but ear tags are seldom used

to control stable flies unless populations are extremely large.

So what do we do now that the effortless method of horn fly control

has quickly come and gone? For one thing, become aware of the horn flies

(and stable flies) on your cattle. Estimate the number of horn flies on

one side of a minimum of 10 animals. Multiply this number by 2 (for

both sides) and divide by 10 to get an average number of flies per

animal. We know that an animal can tolerate 50 flies. If your average

is 50 or more, you should probably treat your animals with a pesticide.

Application methods are the same ones used before ear tags sprays,

backrubbers and dustbags. But to help prevent future resistance problems,

lets discuss the use of the approved pesticides we can choose from,

and develop a strategy for a fly management program.

The 3 main classes of pesticides and some examples of pesticides

from each class that are approved for horn fly control on beef cattle

are shown below:

Chlorinated Hydrocarbons Organophosphates Pyrethroids

methoxychlor stirofos synergized pyrethrum
dichlorvos permethrin
fenthion resmethrin
crotoxyphos flucythrinate
coumaphos fenvalerate
stirofos + dichlorvos
crotoxyphos + dichlorvos

Organophosphates (O.P.'s) are generally the most common of the 3 classes,

and the most toxic. However, they, like the pyrethroids, are beneficial

to the environment because they break down into non-toxic chemicals in

a relatively short time. Chlorinated hydrocarbons are low in toxicity,

but linger in the environment for long periods of time (years). Py-

rethroids are probably the group with the lowest toxicity and the high-

est price. At the present, pyrethroids of any kind are not recommended

for horn fly control because of the resistance problem.

Pesticide manufacturers make it difficult if not impossible for

us to know what we are purchasing by calling their products a variety

of trade names. Lets look at the above-mentioned organophosphates listed

together with some of their trade names:

Organophosphates Trade Names

stirofos Rabon, Gardona
dichlorvos Vapona, DDVP
fenthion Spotton, Baytex
crotoxyphos Ciodrin
coumaphos Co-ral, Muscatox
stirofos + dichlorvos Ra-vap
crotoxyphos + dichlorvos Cio-vap

Read the label carefully and be sure of the pesticide you are buying.

Observe the safety precautions and use only the amount of pesticide

specified on the label.

Now for some management suggestions:

1. Stable fly and horn fly populations peak twice a year, in late May

to early June, and again in late August to late September. If you spray

your cattle, you should plan to spray just before and during these times

if possible.

2. Cattle must be forced to use dustbags. Bags are often hung in lanes

and gates through which cattle must pass to get to feed,.minerals, or

water. Hang bags at the proper height and service them regularly to

insure good results. Dustbags hung under tree limbs in cattle loafing

areas will not control flies simply because they will not be used vol-

untarily by the cattle.

3. Backrubbers should be placed in areas where cattle congregate or

where they must pass daily, such as between food and water or minerals.

Service backrubbers regularly to insure the best results.

4. Make use of all recommended pesticides other than pyrethroids and

use them alternately throughout the year to help prevent a buildup of

resistance. Larvicides fed in pre-mixed mineral supplements should be

used carefully. If pesticides for control of larval and.adult life

stages are being used simultaneously on the same farm, for example

dustbags for adult control and a larvicide pre-mix, be sure the 2 pest-

icides are not the same, and that they are not from the same pesticide

class. For example, Rabon and Ciodrin are both organophosphates and

should not be used simultaneously. Methoxychlor, however, is a chlor-

inated hydrocarbon and could be used simultaneously with Rabon. Simul-

taneous use of the same pesticide or pesticides from the same pesticide

class for control of larval and adult fly populations greatly increases

the chances of resistance levels building in the flies.

5. Since the favorite breeding material for the stable fly is decaying

vegetation, sanitation is an important part of control strategies.

Residues from rolled hay probably account for the majority of stable

fly breeding sites in north and central Florida. Stable fly larvae in

compacted rolled hay residues may number up to several thousand per

square foot of residue. If rolled hay is fed on improved pasture, the

residues will kill the grass beneath them. The first vegetation to

grow through the residues is usually weeds.

The ideal method for feeding rolled hay is to put the rolls on

wagons or some type of mobile platforms. These should be moved week-

ly as hay residues form around them. Residues formed in this manner

will be sparse and will not support stable fly production. If rolled

hay is fed on the ground, which is the most common method, fresh rolls

should not be placed on residues from previous rolls. Each roll should

be placed in a new location each time. Removing rolled hay residues

from fields is a time-consuming job, but it can result in a significant

reduction in stable flies.

6. Over-feeding grain and silage will promote stable fly breeding in

the residues. Large numbers of stable fly larvae have been noted in

residues in and around feed troughs. If feed troughs are portable,

move them as often as necessary to prevent accumulation of residues.

Periodically empty residues from troughs. Clean up spillage around

silos and feed storage bins.

7. Pesticide-impregnated ear tags are usually applied to cattle for

horn fly control. However, these devices will provide some degree of

stable fly control as well. Ear tags should only be used if stable

flies are numerous (20 to 25 per animal).

8. Ciodrin, Vapona, and Ciodrin plus Vapona are approved for application

to beef cattle if needed. Directions for use and safety precautions

can be found on the labels of the various pesticides. These should be

followed carefully.

9. Since the main attraction to the stable fly is the cow, poison fly

baits are ineffective. Residual sprays are usually ineffective unless

they are applied to known sites where stable flies congregate in large


numbers. Few stable flies are attracted to electrocutor-grid traps.

Sources of Information the Florida Cooperative Extension Service,

with offices and county agents throughout the state, is a good local

source of information on fly control. Livestock Protection Pointers are

available through your county agent on a number of related topics. The

Insect Control Guide is also available through the Florida Extension

Service. This excellent book, which lists the pests of livestock in

Florida and the approved pesticides to use for their control, is high-

ly recommended for all livestock producers. The University of Florida

and the US Department of Agriculture have research facilities in

Gainesville where new fly control methods are being devised and tested.

Results of this research are provided to the public through the Florida

Extension Service and trade journals such as the "Florida Cattleman".

References Cited

1. Butler, J. F. 1975. Economics and control of livestock insects.
pp 143-152. IN Proc. FAO/IAEA training course on use of radio-
isotopes and radiation in entomol. Univ. FL Dept. Entomol. Nematol.
and ARS/USDA, Gainesville.

2. Steelman, C. D. 1976. Effects of external and internal arthropod
parasites on domestic livestock production. Annu. Rev. Entomol.



David L. Prichard
Extension Livestock Specialist
NFREC, Quincy, Florida


Growth implants have been used successfully by cattle pro-
ducers since the early 1950's when diethylstilbestrol (DES) was
introduced. Since the 1950's other implants have been developed
which have had a significant economic impact on the growing
and/or finishing phases of beef cattle production. At the
present time there are 7 implants cleared for use in beef cattle
and HEIFER-OID). The first 3 are cleared for use in suckling

Numerous research trials and field demonstrations have been
conducted to compare the performance of implanted cattle to non-
implanted cattle. There have been several trials conducted that
evaluated the relative efficacy of each of these implants under
the same production conditions. The end result of all of these
trials is that implanting cattle in all phases of production is a
cost efficient management tool. Differences in response to each
of these implants is difficult to interpret due to differences in
cattle backgrounds, cattle weights, plane of nutrition, length of
feeding period, proficiency of management and many other factors.

Gain response has been shown to be additive when using im-
plants in conjunction with other management practices such as
worming and the use of feed additives. When we construct a total
beef management program we should be aware of how management
during one phase of production affects performance during another
phase. These relationships are difficult to evaluate yet are
probably the most important considerations in the development of
a total beef management concept needed by the producer.

Implants During the Nursing Phase

Numerous trials have been reported on the effect of growth
promoting implants used during the nursing phase of production.
Research reported in table 1 indicates a response of 4-14% in
average daily gain with an average response of 8.8% during the
nursing phase. Calves were implanted at various times from birth
through approximately 100 days of age with a positive response in
each case. Steers tended to show a greater response than






Corah et al., 1976b
Steers 1.20 (10) 1.37 (11) 1.38 ( 9)f
Heifers 1.39 (16) 1.48 (16) 1.48 (18)

Corah et al., 1977
Steers 1.47 (41) 1.51 (43)d
Steers --- 1.68 (48) ---

Johns et al., 1977
Steers 1.58 (148) 1.66 (267) ---
Heifers 1.52 (143) 1.60 (218) ---

Ward et al., 1977 e
Steers 2.00 (15) 2.18 (16) ---
Heifers 1.81 (15) 1.88 (13)e

aNumber of animals in parentheses.
Daily gain from May 2 November 14.
dImplanted at approximately 75 days of age.
Implanted at average of 44 days and reimplanted
fImplanted at birth and again at 92 days of age.
Implanted with SYNOVEX-H.

70 days later.

Data reported in tables 2 and 6 involved a study at Nebraska
in which 119 calves (3/4 Hereford and 1/4 Angus) born in March
and April were used. Within 24 hours of birth half of the calves
were implanted with 36 mg of RALGRO. At an average of 92 days of
age half of the calves implanted at birth were reimplanted and
half of those not implanted at birth received a 92-day implant.

There was an increase (P<.05) in adjusted weaning weight (36
lb) of steer calves implanted both at birth and at 92 days of age
compared to no implants (table 2). Steer calves implanted only
at birth were 20 Ib heavier than controls, with steer calves
implanted only at 92 days of age 26 lb heavier at weaning; how-
ever, these differences (20 vs 26 lb) were not statistically
significant. Implanting did not significantly affect heifer
weaning weights; however, weaning weights were 6, 14 and 14 lb
heavier for heifers implanted at birth, 92 days and both at birth
and 92 days of age, respectively.



Implant Treatments Adjusted Weaning Weight
At Birth At 92 days No. of calves Steers, lb Heifers, Ib

30 483a 443
I 29 509a,b 457
I 31 503a,b 449
I T 29 519b 457

abMeans with unlike superscripts differ (P<.05).
Ward et al., 1977.

Research by Kansas State at Colby, Kansas, compared one
implant of RALGRO, two implants of RALGRO and one implant of
COMPUDOSE to non-implanted suckling calves in two trials. The
first implant was at 1-3 months of age. The trials were 153 and
175 days in length and calves were reimplanted at 92 and 115
days. Control calves gained. 1.92 and 2.12 lb/day. One RALGRO
implant increased ADG to 1.96 and 2.18 lb/day while calves im-
planted twice with RALGRO gained 1.92 and 2.31 lb/day. Calves
implanted with COMPUDOSE gained 1.92 and 2.14 Ib/day.

A recent trial conducted at the University of Florida evalu-
ated the effects of creep feeding, preweaning RALGRO implants and
breed type on calf performance. Two hundred calves sired by
Brahman and Romana Red bulls and out of Angus and Angus X Brown
Swiss reciprocal crossbred (F ) dams were stratified by breed
type and sex to three creep treatments: (1) no creep feed (NC);
(2) long-term creep (LC), creep-fed from about 60 days of age to
weaning (205 days); and (3) short-term creep (SC), creep-fed from
150 days of age to weaning. Alternate calves within sex, breed
type and creep treatment were implanted with 36 mg of RALGRO at
about 60 days of age and reimplanted 90 days later.

Calves implanted with RALGRO were 20 lb heavier at 150 days
of age and 36 lb heavier at 205 days than non-implanted calves
(table 3). RALGRO implanted calves gained .18 lb more per day,
from the first implant date to the date of the second implant
(60-150 days of age) than did non-implanted calves and .26 lb
more per day from the date of the second implant to weaning.
RALGRO implants did not affect frame score at weaning or
condition score at either 150 or 205 days of age.




205-day wt, lb 524 560****
150-day wt, lb 394 414****
,Frame score 2.9 3.0
Average daily gain, lb
60-205 days 2.25 2.47****
60-150 days 2.20 2.38****
150-205 days 2.34 2.60****
Condition score
205 days 10.7 10.9
150 days 9.5 9.6


There was a tendency toward greater 205-day weight response
to RALGRO implants when calves received creep feed (table 4).
RALGRO implanted calves that were not creep fed weighed 28 lb
more at 205 days of age than did the NC-non-implanted calves.
The 205-day weight advantage for RALGRO implanted over non-
implanted calves was about 40 lb for both the SC and LC groups.



No RALGRO 485 536 549

RALGRO 513 575 590

aWeights are in pounds.

Reimplanting during the nursing phase has shown positive
results, although the amount of response is quite variable and
not very predictable. Nutritional level of the nursing calf and
breed type appear to play an important role in the response to
growth implants.

Implants During the Backgrounding Phase

The most variation in response to implanting seems to be in
studies using cattle in the backgrounding phase of beef product-
ion. This would be expected because of the wide range of
nutritional regimes, age and condition of cattle, breed type and


seasonal differences.

One trial in Missouri using two herds of cattle compared one
and two implants of RALGRO and SYNOVEX to non-implanted controls.
A single implant added 31 and 34 pounds of gain for RALGRO and
SYNOVEX, respectively. Two implants added 54 and 34 pounds,
respectively. In a set of 11 trials ranging in length from 112
to 196 days, cattle given a second implant of RALGRO 70 to 104
days after the first implant gained an average of 9.5 pounds more
than those implanted once. In seven of the 11 trials, the second
implant increased gains from 6.5 to 39.6 pounds. In the other
four trials, average daily gain dropped below .9 pounds after the
second implant and only one herd showed a positive weight

A study was conducted in Alabama from December to June with
steers grazing cool season grasses. One group of steers was
implanted twice with RALGRO during the 178 days and the other
group three times. The steers receiving three implants gained 23
pounds more than the two-implant group.

The effect of RALGRO nursing implants on subsequent growing
reimplantation can be seen in table 6. Average daily gain of
calves implanted while nursing but not reimplanted during the
growing phase was greater (1.71 vs 1.59 lb) than for calves not
receiving a nursing implant, suggesting a carry-over response
into the growing phase. Calves that received both nursing and
growing implants outgained (1.90 vs 1.71 lb/day) calves implanted
only during the nursing phase.


No Growing Implant, lb Growing Implant, Ib

No previous implant 1.59 1.92
Previous implants 1.71 1.90
Carry-over effect .12 -.02

No birth implant 1.57 1.91
Birth implant 1.78 1.90
Carry-over effect .21 -.01

No 92-day implant 1.65 1.82
92-day implant 1.71 2.01
Carry-over effect .06 .19

Ward et al., 1977.

The response to implanting and reimplanting on backgrounding
and growing systems is quite variable and not always positive.
Many management and non-management factors can influence this


response. It would appear that the health and nutritional
management of the cattle may have the most effect on the response
to implanting during the growing or backgrounding phase.

Implants During the Feedlot Phase

It seems that the most consistent data on implanting and
reimplanting is with feedlot research. This would be expected
since maximum gains over an extended period of time are strived

Shown in table 7 is a summary of three trials involving 160
head of cattle that compared the performance of non-implanted
cattle to those that received a single RALGRO implant.


Item Control RALGRO % Improvement

ADG, lb 2.46 2.82 + 14.6
Avg. daily feed
consumption, lb 22.2 23.4 + 5.4
Feed/gain ratio 9.02 8.29 + 8.2

A recent study conducted at Garden City, Kansas compared the
performance of RALGRO, RALGRO reimplant, SYNOVEX reimplant and
COMPUDOSE implanted cattle to controls using 200 yearling steers
fed 146 days. ADG was 2.93, 3.22, 3.31, 3.09 and 2.76 lb/day for
the five groups, respectively. Feed conversion was 6.83, 6.34,
6.48, 6.49 and 7.04, respectively. Reimplanting with RALGRO
increased gains 42 pounds; whereas, reimplanting with SYNOVEX
increased gains 55 pounds over one RALGRO implant.

Research comparing mixed implant programs is limited. This
is in part due to the large number of treatments which result
when single, reimplants, and mixed programs are compared.

Lofgreen (1973) evaluated eight different implant treatments
with 120 steers fed in a feedlot for 142 days (table 8). Initial
implanting with SYNOVEX resulted in a greater (P<.05) daily gain
than initial implanting with RALGRO, 2.56 vs. 2.30 lb/day,
respectively. Ranking of treatments indicated that initial
implanting of SYNOVEX followed by a reimplant of SYNOVEX ranked
first in both ADG and feed conversion.



Treatments Daily Gain [Ranking] Feed/ [Ranking]
(Ib) Gain (Ib)

Control 1.97a [7] 8.80b [7]

SYNOVEX initially b
No additional treatment 2.40bd 4] 740a [4]
SYNOVEX reimplant 2.69d [1] 7.07a (1]
RALGRO reimplant 2.58 [2] 7.33 [2]

MEANS 2.562 7.281

RALGRO Initially
No additional treatment 2.29bc [5] 7.94ab [5]
SYNOVEX Reimplant 2.43bcd [3] 7.41a [3]
RALGRO Reimplant 2.17 [6] 8.11 [6]

MEANS 2.301 7.811

*Adaptad from Lofgreen, 1973
a','o'Means having common superscripts are not significantly
different, P<.05.
Means having common superscripts are not significantly
different, P<.05.
Implant Site

Originally it was assumed that all implants, regardless of
type, should be deposited in the same general location in the
middle of the ear. It has only been during the last 5 years that
implant site has become a research interest.

The traditional implant location was a subcutaneous implanta-
tion on the back side of the ear approximately 1 inch from the
base of the ear. As producers obtained experience implanting
calves, they began asking questions regarding why (and if) the
traditional implant site was really the best location. Producers
mentioned things like: (1) puncturing the ear and depositing
pellets on the ground; (2) ear identification tags and fly tags
getting in the way; (3) skin being tight and hard to correctly
penetrate; (4) takes too long; (5) sometimes the pellets seemed
to not get dissolved; (6) excessive bleeding in too many cases;
(7) infected ears; (8) lack of uniform response; (9) seemed to
crush too many implants and etc.

The question became why not implant subcutaneously in the
pocket of loose skin on top of the fatty tissue near the base of


the ear. This area has become known as the "alternate or deep
site" location.

Personnel from Kansas State University conducted the first
field trial with the alternate site location. Lightweight
Brahman-crossbred heifers were grazed on wheat pasture for 100
days (table 9). Heifers implanted with RALGRO at the alternate
site gained 3.5% faster (P<.10).



Traditional Alternate
Item site site

No. of heifers 107 106
Initial wt., lb 342 340
Final wt., lb 498 502
Total gain, Ib 156 162
ADG, lb 1.56 1.62
Improvement 3.5%*


Corah et al. (1983) summarized the literature available on
implant sit-e Ttable 10). The summary indicates an average
additional improvement in gain of 2.7% when the deep site loca-
tion is used. There is not as much data regarding feed intake
and efficiency but limited data indicate a 1-3% improvement in
feed efficiency.


--Additional Benefit at Base of Ear vs. 1 inch out from Base--
Cattle Type No. No. Increase
Studies Cattle in Gain

Nursing calves 2 178 +1.80%
Grazing yearlings 8 1,393 +2.50%
Feedlot cattle 11 1,251 +3.04%

Overall 19 2,822 +2.70%

Corah, Kuhl and Riley, Kansas State University, 1983. Summary
of studies in Kansas, Minnesota, South Dakota, Tennessee, Texas,
and Wyoming.



The use of growth promoting implants is an effective manage-
ment practice available to all beef producers. The overall
summary of research indicates a positive response in all three
phases of beef production: nursing calves, backgrounding and
feedlot. The degree of response is not necessarily predictable,
particularly in programs with marginal nutrition. Larger gains
are generally observed in better management situations. The use
of growth promoting implants does not substitute for good
management; therefore, for a total implant program to be
successful, cattle need to be exposed to good nutritional and
health programs.


Implant Care and Use

D. L. Prichard
Extension Livestock Specialist
NFREC, Quincy

Implanting cattle has long been recognized as one of the most profitable
investments a cattleman can make. Whether a producer has a few head or
several thousand head, properly administered implants will yield an economic
return of $15 to $35 per head. Therefore, it makes good sense to implant
cattle correctly for maximum dollar returns.

Many cattlemen who use proper implanting techniques fail to follow through
with proper implant care and storage. Implants, which have been cared for
properly, will retain their potency from one year to the next. Cattlemen who
throw their implant guns on the floorboard of their pickup and toss their
extra implants on the dash, after their implanting is finished, can not expect
to receive maximum benefits from growth implants. The following steps are
recommended for maximum implant response.

1. Proper Restraint Proper implantation, as well as safety of
personnel, is best achieved by restraining cattle in a squeeze chute using
head restraint. Nose tongs, can be used for better control of animals.

2. Eartag First Eartag cattle prior to implanting. Place eartags so
they don't prevent proper implant placement and procedure.

3. Have Trained Personnel Properly placed implants mean money. If you
do not know proper implanting procedures, have a qualified person to
demonstrate them for you.

4. Implant the Correct Part of the Ear For proper absorption and
maximum response, place the implant in the correct part of the ear, depending
upon the type of implant. When using Compudose; Synovex C, S, or H; Steer-oid
or Heifer-oid, the implant should be placed beneath the skin on the back side
of the middle one-third of the ear (Figure 1). Ralgro should be implanted
subcutaneously in the pocket of loose skin about one inch from the hard ring
of cartilage you feel at the base of the ear (Figure 2).

area of
Insertion middle loose skin
Site third (base) .

Insertion middle
Site third
\ !

area of
loose skin
(base) /

Figure 1.

Figure 2.


5. Prepare the Implant Site The implant site on the ear should be wiped
clean with an absorbent piece of cloth soaked in a topical germicidal solution
(i.e. rubbing alcohol). Failure to follow antiseptic procedures, especially
when the ears are covered with fecal material, may result in infection and
possible implant loss. Note: Avoid getting any of the germicidal solution
into the animal's eyes.

6. Proper Needle Insertion Grasp the ear firmly with one hand. With
the other hand insert the needle between the skin and cartilage, avoiding
major blood vessels. The needle should be eased forward on a lateral plane
until the full length of the needle is under the skin. Pull back about
one-half inch, then pull or push the trigger on the implant gun as you pull
the needle out with a steady slow movement. This procedure should prevent
broken or crushed implants that could lead to possible reduced weight gains.
Note: Full insertion of the needle is important for maximum implant retention
and proper absorption.

7. Disinfect the Needle After each use, the needle should be wiped
clean or dipped into the germicidal solution.

8. Proper Implant Gun and Needle Care The implant gun requires minimum
maintenance. Periodically clean the entire implant gun with warm, soapy
water. Clean the plunger with the needle removed while it is extended. Dry
the implant gun thoroughly following cleaning. When the needle becomes dull,
either replace with a new needle or sharpen with a file. Do not let the
needle become too short as a result from filing. Regularly inspect needles
for burrs. A burr may damage implants and affect absorption.

9. Properly Store Unused Implants Place unused implants in a cool, dry
place ... not in a refrigerator. The high-humid environment of a refrigerator
may soften certain implant pellets and result in less weight gain. It is
recommended to store implant cartridges in a sealed plastic bag.

10. Take Time when Implanting Do not sacrifice proper technique for
speed. Make sure every animal is implanted correctly. If the needle
punctures the entire ear or a blood vessel is penetrated, take time to
reinsert the needle properly. If this occurs one may wish to use the other
ear. Ruptured blood vessels will result in rapid absorption of the implant.

11. Reimplant Reimplant as recommended by the manufacturer.

12. Periodically Check Technicians A manager should make daily spot
checks to observe that his personnel are using proper implanting techniques.




Rolf E. Larsen and Antonio Garcia
College of Veterinary Medicine
University of Florida, Gainesville, Florida

Libido testing of beef bulls is a current topic of interest
and discussion. Libodo as discussed here will be defined as sex
drive or sexual aggressiveness. A variety of terms may be used to
describe this behavior but we will limit this vocabulary to two
terms. "Libido" will be used to describe general sexual
activity or level of activity. "Serving capacity" will be the
term used to describe the number of matings a bull is able and
willing to perform in a test situation. Other terms are sometimes
used for related activity. "Reaction time" is the length of
time from first contact with a receptive cow to actual mating.
"Serving ability" or "mating ability" are sometimes used in
descriptions of coordination and agility and efficiency in
breeding. "Social dominance" is used to describe the
interactions related to social rank between bulls in multiple sire

While libido testing of bulls has been the subject of a
number of serious investigations since the 1950s, it has not been
utilized by many livestock farming operations. Since the benefits
of selecting and using bulls with superior libido are clearly
related to higher profitability why are we just beginning to
seriously discuss this topic with purebred and commercial
producers? The list of reasons would be long but that list would
include the following factors.

1) The failure to use a limited breeding season: The
benefits of using bulls with high libido or serving capacity are
most obvious and quantifiable under management systems using a
limited period of the year for breeding. As this type of
management becomes universal and as breeding seasons become
shorter more rigorous selection of bulls for fertility becomes
more obviously profitable.

2) Lack of a standardized test: While most investigators
can demonstrate a benefit to selection of bulls for good serving
capacity there are a number of different test systems used which
confuse the issue. Problems to be resolved include the length of
the test, the number of tests necessary, and the number of bulls
which can be tested simultaneously.

3) Manpower and time: The facilities for testing are
usually available to most producers at little cost. A day of
testing, however, requires at least 3-4 people present for the
duration of the test period.


4) Selection means willingness to cull: Serving capacity
appears to be unrelated to production traits and semen quality.
Therefore, an additional test which may dictate culling of bulls
with good pedigrees and conformation is not always welcome.

Libido testing has been attempted in pastures with
free-ranging cows in heat and in corrals with restrained cows or
unrestrained cows in heat. Corral tests with restrained cows have
used cows in natural estrus, ovariectanized cows given estrogen,
and cows not in heat. Duration of tests has varied from 5 minutes
to days and some systems test each bull individually while others
test 4-5 bulls simultaneously.

Over the years it has been demonstrated that if a short
(practical) test period is to be used, the cows must be
restrained. This usually is accomplished by mounting stanchions
along the side of a corral with short side-bars to prevent
side-to-side movement by the cows.' The use of cows in heat is
generally viewed as unnecessary since immobility of the cow seems
to be an adequate stimulus to the bull for mounting and mating.
This also greatly simplifies the preparation for a test.

One system used for performing and scoring a libido test was
set up with two cows restrained in a corral with two bulls allowed
with them for 10 minutes. The bulls were scored by the following

0 = no interest shown

1 = interest shown only once

2 = interest shown more than once

3 = active interest throughout test period

4 = one mount or attempt to mount

5 = two mounts or attempts; no service

6 = more than two mounts; no service

7 = one service followed by no further interest

8 = one service followed by further interest or mounts

9 = two services followed by no further interest

10 = two services followed by interest, including further
mounts and services


This scoring system had the advantage of ranking animals which did
not serve a cow, something of interest in studies which included
Brahman breed bulls. Brahman bulls rarely mate during short corral
test conditions.

Serving Capacity testing has a simpler and more demanding
endpoint. The serving capacity score of an animal is simply the
number of successful matings performed in the test period. For
this test 5 or 10 minutes was considered too short for effective
testing. Blockey, in Australia, worked with a 40 minute test in
which same-age bulls in groups of 5 were placed in a corral with 4
restrained heifers. 'Based on fertility trials with these bulls he
recarmended that only bulls with 3 or more services during the
test be used for pasture breeding. Use of bulls with 0, 1, or 2
breeding in the test period resulted in poor conception rates at
first service and poor pregnancy rate even after a breeding season
of 10 weeks.

Those people who have observed libido and serving capacity
testing know that 40 minutes is a long time to watch bulls in a
corral. The 40 minute period was selected after it was observed
that during a 3 hour test, 80% of the matings took place inthe
first hour. In 45 minute tests run in Florida, 93% of all
services were completed in the first 30 minutes. Ten minutes
appears to be too short. In one Florida test in 1980-the average
time to first service was 10.59 minutes. There may be a trend to
utilize a 20 minute test period as a compromise, with a serving
capacity of 0-1 considered poor, 2-3 ranked medium, and 4 and
higher considered high serving capacity.

The duration of the test period has shortened for obvious
reasons of practicality. In Blockey's experiments in Australia a
three hour corral test with restrained heifers had a correlation
coefficient of .92 with a 19 day pasture test, but since the first
hour of that test had a correlation of .91, one hour was
considered satisfactory. Further testing demonstrated that the
first 40 minutes of the test told most of the story (correlation
coefficient of .99 as compared to 1 hour). Reduction to 30
minutes seemed reasonable with different herds giving correlation
coefficients of .94-.98 compared to the 40 minute test. Reduction
to 20 minutes lowered the correlation coefficient as compared to
the 40 minute test to an average .91. This may or may not be good
enough, depending on whether the interested party is buyer,
seller, or herd manager.

It has been demonstrated in a number of investigations that
high libido and serving capacity tend to be highly influenced by
genetic factors. Experiments in Europe with identical twins
established this. More recently, an experiment with identical
twins in Australia demonstrated the similarity in serving capacity
very effectively in two one-hour tests.


Table 1. Serving Capacity of Identical Twin Bulls

Bull # Test 1 Test 2

Twin la 7 7
lb 8 8

Twin 2a* 2 (11 mounts) 3 (15 mounts)
2b* 7 (13 mounts) 9 (14 mounts)

Twin 3a 4 2
3b 4 1

Twin 4a 2 1
4b 2 0

Twin 5a 4 3
5b 4 4

*Twins 2a and 2b had a penile abnormality

Fran: Blockey: Applied Animal Ethology 7:321-336 (1981).

What are the advantages to performing a serving capacity test
and utilizing a high serving capacity bulls? The observation of
the bulls during the test allows an evaluation of their physical
abilities and defects which are not always obvious on either semen
evaluation or observation in the bull herd. Incoordination during
mounts, penile defects, and lameness may become apparent during
the stress of repeated mounting and breeding. The advantage of
using high serving capacity bulls over low serving capacity bulls
in maximizing conception rate has been demonstrated again and
again. The differences among the medium and high ranked group is
more subtle but becomes important with the use of limited breeding
season management systems. A high conception rate on the first
estrus of the breeding season means more weight on calves weaned
during that pregnancy and lactation cycle. It also gives a better
opportunity for early conception the following year since the cow
will calve well before the next breeding season and have time to
recover from the stress of calving and early lactation.

Heifers and cows restrained for the bulls mounting and
services need not be in heat. In fact, there is same sentiment
that if none are in heat there is less tendency for the bulls to
congregate around a single female. They should be restrained in a
stanchion with side bars which extend to the rib cage. Simply


tethering the female to a post allows too much side-to-side
movement and forces many mounts by the bull to be aborted. The
heifers and cows can generally tolerate 60-90 minutes of mounting
and mating. They should be replaced after 20-25 matings or if any
bleeding from the vulva occurs. Injuries to the heifers are
possible but are rare. In fact, sane studies have utilized
pregnant cows, with no damage to the pregnancy resulting. This is
not recommended however. It can be deduced from this that one
female for every 3-4 bulls to be tested should be available at the
beginning of a test day.

Bull to cow ratio has often been 5 bulls to 4 cows in
research work. A ratio of 5 bulls to 2 cows gives similar results
if young same-age bulls are being tested. We have commonly used 5
bulls with 5 cows with good results. Smaller groups or even one
bull with one cow may provide equal or better results but time
available generally prevents serious consideration of this
system. It is a good idea to have one observer for each bull in a
test group.

Bull stimulation is necessary for best response. That
stimulation is provided by placing a group of bulls to be tested
in an adjoining corral so they can watch the previous group. That
effectively gives each group of bulls, except the first group, one
test period of stimulation immediately prior to their own test.
Stimulation for the first group can be provided by other bulls not
taking part in a test or they can be tested a second time later in
the day. Ten minutes of visual stimulation is adequate for the
bulls to perform well, with results no different from testing
after 60 minutes of stimulation.

Multiple tests have been suggested as necessary for young
virgin bulls if they are to show their true potential. Lunstra,
in Nebraska, working with 50 yearling hereford bulls given 30
minute tests every 4 days, found the number of matings increased
for the first 3 tests and then stabilized. There is apparently a
learning and acclimatization aspect to the test conditions. In an
Australian experiment with 41, 20-month virgin Hereford bulls,
there was little change from the first 40 minute test to a second
test two weeks later. In test #1, the mean serving capacity was
6.74 (range 0-28) while the second test resulted in a mean of
6.78. There were three bulls, however, which had a serving
capacity of 0, 0, and 4 on the first test, but served 5, 6, and 9
times respectively on the second test. The results suggest that
if a bull achieves a satisfactory result on the first test he is
likely to be satisfactory on subsequent tests. Bulls performing
poorly on the first test may require a second chance, if only to
identify those few bulls who needed the longer learning time to
achieve a serving capacity score which matches their ability.



Blockey, M.A. DeB: Development of a Serving Capacity Test
for Beef Bulls. Applied Animal Ethology 7:307-319 (1981).

Blockey, M.A. DeB: Modification of a Serving Capacity Test
for Beef Bulls. Applied Animal Ethology 7:321-336 (1981).

Blockey, M.A. DeB: Further Studies on the Serving Capacity
Test for Beef Bulls. Applied Animal Ethology 7:337-350 (1981).

Chenoweth, P.J.: Libido Breeding Soundness, and Fertility of
Range Bulls. Proceedings Annual Mtng Society for Theriogenology.
pp 65-82 (1978).

Chenoweth, P.J., Brinks, J.S. and Nett, T.M.: A Canparison
of three Methods of Assessing Sex-Drive in Yearling Bulls and
Relationships with Testosterone and -I Levels. Theriogenology
12:223-233 (1979).

Chenoweth, P.J., Farin, P.W., Mateos, E.R., Rupp, G.P. and
Pexton, J.E.: Breeding Soundness and Sex Drive by Breed and Age
in Beef Bulls Used for Natural Mating. Theriogenology 22:341-349

Falcon C.: The Relationship of Breeding Soundness and Libido
Evaluation to Subsequent Fertility in Beef Bulls. Masters Thesis.
University of Florida (1981).

Lunstra, D.D.: Evaluation of Libido in Beef Bulls.
Proceedings Annual Mtng Society for Theriogenology. pp 169-177

Lunstra, D.D. and Laster, D.B.: Influence of Single-Sire and
Multiple-Sire Natural Mating on Pregnancy Rate of Beef Heifers.
Theriogenology 18:373-382 (1982).

Lunstra, D.D.: Changes in Libido-Fertility Relationships as
Beef Bulls Mature (abstract). J. Anim. Sci. 59(Suppl. 1):351

Mader, D.R. and Price, E.O.: The Effects of Sexual
Stimulations on the Sexual Performance of Hereford Bulls. J.
Anim. Sci 59:294-300 (1984).

Osborne, H.G., Williams, L.G. and Galloway, D.B.: A Test for
Libido and Serving Ability in Beef Bulls. Austr. Vet. J.
47:465-467 (1971).

Pruitt, R.J. and Corah, L.R.: Effect of Energy Intake After
Weaning on the Sexual Development of Beef Bulls. I. Semen
Characteristics and Serving Capacity. J. Anim. Sci. 61:1186-1193











Evaluate bulls for
breeding soundness

Calves born

Jan. 20 March 20

(60 days)


April 15 June 15

(60 days)

Replacement Heifers:
Vibrio Lepto
Deworm, as needed

1) Herd bulls and
post calving cows:
Vibrio Lepto
Deworm, as needed

2) Insert insecticide
ear tags first week
of April

3) Check cow herd for
repeat breeders

4 4 1

1) Remove herd bulls
June 15

2) Check for pinkeye
and foot rot and
treat as needed

Insert insecticide ear
tags first week of

1) Weigh and ear tag
new calves daily

2) Check for calving
difficulty; retained
placentas, etc.

3) Check calves daily;
treat for scours,
as needed

Implant steer calves

Continue to check for
and treat sick calves

Heifers ST 19
Deworm, as needed

Implant steer calves

1) Preg check --cull Grub and louse control
Wean and
SEPTEMBER open cows and poor
grade calves producers
2) Grub & louse control
1) Vaccinate calves for
Blackleg (Clostridia)
OCTOBER 2) Vaccinate heifer
ca I ves for Bruce II os i
1) Purchase needed
herd sires
2) Buy only above av-
erage performance
tested bulls
Select 1) Deworm calves
DECEMBER Vaccinate cows with E.
Replacement Coli Bacterin for pre- 2) Implant all calves
Heifers vention of calf scours except repl. heifers
H eife rs




Weigh and ear tag new calves daily; castrate and dehorn as
soon as possible; check calves daily and treat for scours
as needed.
Check cows twice daily for calving difficulties; check for
retained placentas and prolapsed uteruses and treat as
Continue supplemental feeding of breeding herd; increase
amount of feed and protein supplement in proportion to the
number of calves born.
Keep first calf heifers separated from cow herd and pro-
vide them with the best winter feed or rotate them on and
off of small grain pastures.
Check mineral and salt feeders daily; watch for grass
tetany on winter pastures; feed high magnesium mineral.
Supplement cattle on winter pastures if cold weather
limits pasture growth.
Make up breedi-ng herd lists.
Examine bulls for breeding soundness and semen quality
prior to breeding season.
Provide quality winter feed for herd bulls to condition
them for the breeding season.
Begin grazing winter clover pastures when clover is ap-
proximately six to eight inches high.
Vaccinate (first week in January) all pregnant females
with second injection of E. coli bacterin for prevention
of calf scours.
Follow CBDU Herd Health Calendar.


Continue with January management practices.
Apply nitrogen to winter pastures.
Plan forage program for coming year.
Check mineral and salt feeders daily; watch for grass
tetany on winter pastures; feed high magnesium mineral.
Repair facilities and machinery when time permits.
Follow CBDU Herd Health Calendar.


Continue with January and February management procedures.
Prepare land for summer crops where possible.
Check for insect damage on alfalfa; cut for hay when
Check mineral and salt feeders daily; watch for grass
tetany on winter pastures; feed high magnesium mineral.
Repair facilities and machinery when time permits.
Follow CBDU Herd Health Calendar.



Begin breeding season, put bulls in with cows about April
Plant warm season annual pastures where and when possible.
Observe cows for repeat breeders; rotate bulls if neces-
Check mineral and salt feeders daily.
Begin grazing warm season permanent pastures.
Harvest hay from winter annual crops and/or alfalfa.
Cut rye-ryegrass pasture for hay in flower stage and
follow with millet.
Cut alfalfa at 25% bloom stage and fertilize with 250 lbs
of 0-10-20 plus 1 lb of boron/acre.
Cull cows that have not calved or that have lost their
Follow CBDU Herd Health Calendar.


Graze small grain pastures as long as possible.
Fertilize warm season pastures with 400# 13-13-13 per
Check mineral and salt feeders daily.
Prepare land for summer millet and forage sorghum.
Continue close management of alfalfa.
Follow CBDU Herd Health Calendar.


Remove herd bulls about June 15.
Continue with May management procedures.
Control weeds in summer pasture.
Plant summer millet and forage sorghum.
Continue alfalfa management.
Follow CBDU Herd Health Calendar.


Graze millet when sufficient growth has taken place;
rotationally graze to avoid overgrazing.
Check pastures for armyworms and mole crickets and treat
if necessary.
Control weeds in summer pasture.
Check mineral and salt feeders daily.
Apply nitrogen to warm season pastures.
Continue alfalfa management.
Follow CBDU Herd Health Calendar.


Continue July management practices.
Cut excess perennial summer pasture for hay.
Make plans for winter annual forages.


August (Continued)

Prepare alfalfa plots for fall grazing of weaned calves.
Rotationally graze millet to avoid overgrazing.
Control and spray for weeds in summer pastures.
Apply nitrogen to warm season pastures.
Check mineral and salt-feeders daily.
Follow CBDU Herd Health Calendar.


Continue to cut hay for winter feed.
Cut forage sorghum for silage.
Wean and grade calves; pregnancy test cows.
Send open and cull cows and calves to the market.
Let cow herd clean up millet and forage sorghum crop
Assign weaned calves to alfalfa plots and other feeding
Start land preparation for small grain plantings.
Check mineral and salt feeders daily.
Vaccinate heifers for brucellosis.
Deworm fall weaned calves and cow herd if necessary.
Review winter feed supplies and feeding plans so that
needed adjustments can be made before supplies tighten and
prices rise.
Follow CBDU Herd Health Calendar.


Continue to graze cow herd on crop and summer pasture
residues; start feeding silage and protein supplement when
pastures become inadequate.
Plant small grain pastures when moisture is adequate.
Mow weeds in permanent pastures.
Continue to monitor alfalfa and other feeding programs for
weaned calves.
Check mineral and salt feeders daily.
Repair handling facilities and equipment and keep them in
good working order.
Follow CBDU Herd Health Calendar.


Maintain adequate nutrition level for cow herd; monitor
condition of cows closely.
Continue to monitor alfalfa and other feeding programs for
weaned calves.
Check mineral and salt feeders daily; use a high level of
magnesium in mineral.
Have soils tested; apply fertilizer (especially N) to
small grain pastures.
Re-evaluate winter feeding plans and feed supplies.


November (Continued)

Purchase new herd bulls if needed.
Follow CBDU Herd Health Calendar.


Monitor condition of cows closely, maintain an adequate
level of nutrition for cow herd; begin supplemental feed-
ing if necessary.
Continue feeding trials for weaned calves; begin grazing
small grain pastures (if ready).
Prepare for calving season; separate first calf heifers
from main cow herd for feeding and observational purposes.
Check cattle for internal and external parasites and treat
if needed.
Vaccinate all pregnant females with first injection of E.
coli bacterin for prevention of calf scours.
Reimplant all calves except replacement heifers that are
on feeding trials.
Repair equipment for spring plantings; maintain buildings
and fences.
Check mineral and salt feeders; use a high level of mag-
nesium in mineral.
Freeze brand all replacement heifers.
Follow CBDU Herd Health Calendar.

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