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 Front Cover
 Title Page
 Introduction, and Materials and...
 Results and discussion
 Summary and conclusions
 Literature cited
 Back Cover
 Historic note






Group Title: Bulletin - Agricultural Experiment Stations, University of Florida ; 821 (technical)
Title: Production of grade Hereford, Beefmaster x Hereford, and Braford x Hereford calves in south Florida
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Full Citation
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Permanent Link: http://ufdc.ufl.edu/UF00027456/00001
 Material Information
Title: Production of grade Hereford, Beefmaster x Hereford, and Braford x Hereford calves in south Florida
Series Title: Bulletin Agricultural Experiment Stations, University of Florida
Physical Description: 6 p. : ; 23 cm.
Language: English
Creator: Crockett, J. R ( Joe Richard ), 1926-
Koger, Marvin, 1915-
Publisher: Agricultural Experiment Stations, Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville Fla.
Publication Date: 1982
 Subjects
Subject: Beef cattle -- Breeding -- Florida   ( lcsh )
Calves -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Bibliography: p. 6.
Statement of Responsibility: J.R. Crockett and M. Koger.
 Record Information
Bibliographic ID: UF00027456
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000405068
oclc - 10759278
notis - ACF1298

Table of Contents
    Front Cover
        Front Cover
    Title Page
        Title Page
    Introduction, and Materials and methods
        Page 1
    Results and discussion
        Page 2
        Page 3
    Summary and conclusions
        Page 4
        Page 5
    Literature cited
        Page 6
    Back Cover
        Page 7
    Historic note
        Page 8
Full Text

Bulletin 821 (technical)


Production of Grade Hereford,
Beefmaster x Hereford, and
Braford x Hereford Calves in
South Florida


J. R. Crockett and M. Koger



LG1CULTURAL LIBRARY

JV 0 7713










Agricultural Experiment Stations
Institute of Food and Agricultural Sciences
University of Florida, Gainesville
F.A. Wood, Dean for Research


March 1982








Production of Grade Hereford,
Beefmaster x Hereford, and
Braford x Hereford Calves in
South Florida


J. R. Crockett and M. Koger




















Authors
Dr. Crockett is Associate Professor (Associate Animal Geneticist),
Agricultural Research and Education Center, Belle Glade. Dr.
Koger is Professor (Animal Geneticist) Animal Science Department,
University of Florida, Gainesville.







INTRODUCTION
In any discussion of beef cattle production in a particular environ-
ment the matter of climatic adaptability is of prime consideration.
Adaptation for beef cattle might be defined as the ability to
reproduce, grow and thrive under local environmental conditions.
Much has been written about the ability or inability of temperate
zone breeds of cattle to adapt to hot, humid, subtropical en-
vironments. Most of the research on this subject has been sum-
marized by Cunha et al. (2)1 and Koger et al. (4).
According to Bonsma (1), "the reason livestock procedures resort
to a system of crossbreeding and afterwards, ... to breed creation,
is that the two main types of domestic livestock ... do not perform
satisfactorily in all respects under unfavorable environmental con-
ditions in which we want to maintain these cattle". The literature is
void of work conducted where strains of temperate zone breeds of
cattle have been developed for use in tropical or subtropical en-
vironments, however, it generally has been assumed that the
Shorthorn of Australia and the Criollo of Latin America have
undergone some adaptation to tropical conditions (5).
This bulletin describes the development of a herd of grade
Hereford cattle maintained under subtropical conditions in south
Florida for a period of more than 40 years and presents the results of
an experiment comparing straightbred Hereford cattle of this strain
with the first cross (F1) progeny of these cows sired by Beefmaster
and Braford (breeds which were both developed from crossing Bos
taurus and Bos indicus cattle) bulls.
MATERIALS AND METHODS
This study was conducted on the Brighton Reservation of the
Seminole Tribe of Florida. The reservation is located between 27
and 27 10' N on the northwestern side of Lake Okeechobee.
Average elevation is approximately 6.4 meters (21 feet), with an
average rainfall of 1320 mm (52 inches) occurring mostly in June,
July, August and September but with distribution throughout the
year. The average maximum and minimum temperatures are ap-
proximately 29 o and 16 C (85 and 60F) with highs in the middle
90's F and lows in the middle 20's F. Humidity ranges from 55 to
100% with an average near 75%.
Females used in this study were descendants of Herefords
brought onto the reservation from Arizona (San Carlos Apache
Reservation) in 1936 and 1938. These cattle underwent natural
'Numbers in parentheses refer to literature cited.







selection (survival of the fittest) for approximately 25 years.
Though Brahman bulls were used for a time on some of the females
during the beginning years, Hereford bulls were the predominant
herd sires used. Many of the introduced Hereford bulls, however,
were under considerable environmental stress and some failed to
survive the rigors of the environment.
In 1964, a group of approximately 300 females was selected from
a total of about 3500 to determine the feasibility of producing high
quality range bulls for this particular environment. Selection was
based on pregnancy status of the cows and phenotype of their nurs-
ing calves. The females were divided into six two-sire herds, which
were managed on semi-improved pastures. Registered Hereford
bulls were introduced at this time. During subsequent years, inten-
sive selection for reproduction and production was practiced on the
progeny of the foundation females with highly selected female pro-
geny being returned to the cow herd and selected bull progeny going
to the commercial range herd. Highly selected males were returned
to the foundation herd for use as herd sires. By 1970 the entire bull
battery consisted of bulls raised within the herd. In 1975 it ap-
peared that the calves from the range herd contained too much
British blood and a decision was made to infuse a low level of
Brahman breeding into the herd. The Beefmaster and Braford
breeds were chosen for this purpose rather than straight Brahman
bulls. In 1976 the existing grade Hereford females were divided into
three equal 2-sire herds to be mated, respectively, to Beefmaster,
Braford or Hereford bulls.
The breeding season began March 1 and was 70 days in length.
Calves were born in December and January, and weaned the first
week of August at an average age of 237 days. Females were bred to
calve first at three years of age and all females were palpated in
September and culled the first time open. The cattle were maintain-
ed on Pangola grass (Digitaria decumbens) pastures and received
16% protein cane molasses as a supplement during the winter.
Data from the 1976 through 1980 calf crops were analyzed using
the least squares technique described by Harvey (3). Data collected
included pregnancy rate as determined by palpation, survival from
birth to weaning and weaning weight, while unadjusted 205-day
weight was calculated. Year, breed of sire, sex of calf, age of dam
and breed x sex interaction were the variables used in the model
(Table 1).
RESULTS AND DISCUSSION
Pregnancy rate. The effect of year was included in the analyses
(Table 1) to increase precision and, as usual in this type of data, was







highly significant (P<.01). During previous years, conception rate
for the herd had averaged near 90%. In this study, however,
reproduction was more erratic with a high of 91% in 1977 and a low
of 79% in 1979 (Table 2). It was concluded that either climatic condi-
tions or management or a combination of the two was the probable
cause.
The only other factor influencing pregnancy rate was that of age
of dam (P<.01). As shown in Table 2, three-year-old cows nursing
their first calves had a conception rate of 76% as compared 89, 87,
and 87% for the first exposure females and the two older cow
groups, respectively. This was due primarily to the management of
the younger females entering the herd as two-year-olds. They were
bred with the cow herd and were given no preferential treatment
following their first parturition. This behavior is common in young
females in Florida that are not given special attention.
Survival rate. This response trait showed only age of dam to have
a significant effect (P<.05). The youngest cows (three-year-olds)
lost a few more calves from birth to weaning. Observations would
suggest that difficult birth was not a prime factor. Calves usually
were born alive but did not survive.
Weaning weight. This trait was influenced by year, sex of calf and
age of dam (P < .01) and breed of sire (P < .05). As in much other data
of this kind, year and age of dam would be expected to have a
significant effect. Most research shows that young first calf cows do
not perform as well as older cows up to 10 years of age and most
data is adjusted for age differences. However, in this study the
young (three-year-old) cows were equally as productive as cows in

Table 1. Probability values from analyses of variance for performance traits.
Pregnancy Survival Weaning 205-day
Source df rate rate weight weight

Years 4 ** NS ** **
Breed of sire 2 NS NS **
Sex of calf 1 ** **
Age of dam 3 ** ** **
Breed x sex 2 NS NS
df for remainder 1457 1065 1019 1019
** = P<.01
= P<.05
NS = nonsignificant.







the four-year-old and five-to nine-year old age groups with average
calf weanings weights of 219.9 kg (485 pounds), 220.4 kg (486
pounds) and 220.9 kg (487 pounds), respectively (Table 2). Calves
weaned from ten-year-old and older cows were significantly lower
(P< .01) at 207.7 kg (458 pounds) than those from younger females.
Numbers were small in this group due to the practice of culling cows
over ten years of age. One possible explanation for the above
average performance of the young cows is probably due to selection
on their dam's production record.
The most surprising result was the rather small difference be-
tween breed of sire groups with 220.4 kg (486 pounds), 216.4 kg (477
pounds) and 214.5 kg (473 pounds) for calves sired by Beefmaster,
Hereford and Braford bulls, respectively. More surprising was the
observation that adapted grade Hereford calves were comparable to
those of the two Brahman-derivative sire breeds.
Breed-of-sire differences for estimated 205-day weight were more
significant than those for actual weaning weight (P <.05 vs. P <.01)
as shown in Table 2. This was due to the Beefmaster sired calves
averaging five and three days younger in age, respectively, at wean-
ing than the Braford and Hereford sired calves.
SUMMARY AND CONCLUSIONS
The performance of straightbred grade Hereford calves was com-
pared to that of offspring from comparable dams mated to Beef-
master and Braford sires. Breed of sire significantly affected
(P<.05) actual weaning weight and 205-day weight (P<.01). The
five-year average, however, showed a difference in weaning weight
of only 5.9 kg (13 pounds) between the heaviest (Beefmaster) and
lightest (Braford) groups.
Age of dam had a more significant effect on performance traits
studied (pregnancy, P<.01 survival; P<.05; weaning weight,
P<.01; and 205-day weight, P<.01) than did breed of sire. Three-
year-olds nursing their first calves were lower in conception than
younger and older cows, showed a lower survival rate than calves
from older cows. Cows ten years old and older failed to wean as
heavy calves as did younger cows.
These data indicate that temperate zone breeds, which have
become adapted to subtropical conditions through natural selection
and a period of intense artificial selection, can be made to perform
competitively with breeds adapted to subtropical environments.
However, this would involve a long time adjustment. If this par-
ticular group of females had not been well adapted it is possible that
more observable difference would have been noted in performance.
This bulletin contains only data obtained on performance of
Hereford dams and their straightbred and crossbred progeny. It ap-






Table 2. Least squares means for performance traits.

Pregnancy Survival a Weaning 205-day
Effect N rate (%) N rate (%) N weight (kg)b weight (kg)


Breed of sire
Beefmaster
Braford
Hereford


Age of dam
3 years
4 years
5-9 years
10 years and older

Years
1976
1977
1978
1979
1980

Mean or total


306
264
695
202



317
302
308
290
250

1467


84.3
84.8
85.4



89.0
76.0
87.4
87.0



84.2
91.0
90.0
79.0
80.4

84.8


249
190
523
113



212
252
235
184
192

1075


92.6
96.9
97.5
96.6



98.4
93.2
95.3
96.1
96.5

95.9


230
183
510
109



208
235
225
178
186

1032


220.4
214.5
216.4



220.0
220.4
220.9
207.7



207.7
210.0
200.5
233.2
234.1

217.3


197.3
191.1
190.5



192.8
196.9
197.3
183.3



194.1
179.6
177.8
203.7
208.7

192.8


a Differences between numbers for pregnancy and survival were due both to open cows being excluded from the latter and
to culling low producing and unsound cows that were pregnant.
b1 kg = 2.205 pounds.







peared that heterosis levels for weaning weights, obtained from
mating Beefmaster and Braford bulls to these females, were very
low (1.8% and -0.08% for Beefmaster-and Braford-sired calves,
respectively). Most research data has shown that higher heterosis
levels are obtained when cattle of Zebu (Bos indicus) and British
(Bos taurus) breeding are intermated than when matings are made
between breeds of British breeding (4). The same source presented
data indicating that certain levels of Zebu breeding were essential
for adaptation to tropic and subtropic environments. In this study
the theoretical amount of Zebu breeding contributed from the Beef-
master and Braford bulls to their progeny was 25% and 18.75%,
respectively. As upgrading continues with the Beefmaster (47-50%
Zebu) and Braford (37.5% Zebu) it is highly probable that after three
or four generations more pronounced differences will appear.

LITERATURE CITED

1. Bonsma, J. C. 1973. In Crossbreeding Beef Cattle, Series 2, M.
Koger, T. J. Cunha and A. C. Warnick (Eds.) 1973. University of
Florida Press, Gainesville.
2. Cunha, T. J., M. Koger and A. C. Warnick (Eds.) 1963.
Crossbreeding Beef Cattle. University of Florida Press,
Gainesville.
3. Harvey, W. R. 1960. Least-squares Analyses of Data With Un-
equal Subclass Numbers. U.S.D.A. ARS 20-8.
4. Koger, M., T. J. Cunha and A. C. Warnick (Eds.) 1973.
Crossbreeding Beef Cattle, Series 2. University of Florida Press,
Gainesville.
5. Rouse, J. E. 1969. World Cattle I. University of Oklahoma
Press, Norman.







































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Agricultural Experiment Stations are open to all persons regardless of race,
color, national origin, age, sex, or handicap.


This publication was promulgated at a cost of $855.35, or 24.4
cents per copy, to report results from crossing Hereford cattle
adapted to south Florida with Hereford, Beefmaster and Braford
bulls.


WFAS









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Agricultural Sciences and should be
used only to trace the historic work of
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