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Beef production from straightbreds and reciprocal crosses of Angus, Brahman, and Charolais cattle

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Beef production from straightbreds and reciprocal crosses of Angus, Brahman, and Charolais cattle
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Bulletin Agricultural Experiment Stations, University of Florida
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Peacock, F. M ( Fentress McCoughan ), 1922-
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Gainesville Fla
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Agricultural Experiment Stations, Institute of Food and Agricultural Sciences, University of Florida
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English
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11 p. : ; 23 cm.

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Beef cattle -- Breeding ( lcsh )
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bibliography ( marcgt )
non-fiction ( marcgt )

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Bibliography: p. 11.
Statement of Responsibility:
F. M. Peacock ... [et al.].

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December 1979 Bulletin 810 (technical)



Beef Production from Straightbreds
and Reciprocal Crosses of
Angus, Brahman, and Charolais Cattle


F. M. Peacock, M. Koger, E. M. Hodges,
J. R. Crockett, and A. C. Warnick

"KUME LIBRARY

MAR 21 1980

i.F.A.S. Univ. of Florida











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













Beef Production from Straightbreds
and Reciprocal Crosses of
Angus, Brahman, and Charolais Cattle


F. M. Peacock, M. Koger, E. M. Hodges,
J. R. Crockett, and A. C. Warnick













This public document was promulgated at an annual cost of
$1020 or a cost of 250 per copy to report results from cross-
breeding Angus, Brahman, and Charolais breeds as a tool for
improvement in beef production through breeding tech-
niques.

AUTHORS
Mr. Peacock is a Professor of Animal Husbandry at the Agricultural
Research Center, Ona. Dr. Koger is a Professor of Animal Genetics in the
Animal Science Department, Gainesville. Dr. Hodges is a Professor of
Agronomy at the Agricultural Research Center, Ona. Dr. Crockett is an
Associate Professor of Animal Genetics at the Agricultural Research and
Education Center, Belle Glade. Dr. Warnick is a Professor of Animal
Physiology in the Animal Science Department, Gainesville.

















CONTENTS
PAGE
INTRODUCTION .................................... 1
MATERIALS AND METHODS .......................... 1
Data Analyses ................................... 2
EXPERIMENTAL RESULTS ........................... 2
Reproduction .................................... 3
Pregnancy rate ................................. 3
Calf survival ................................... 5
Weaning rate .................................. 6
W meaning Traits ................................... 6
Age of calf at weaning ............................ 6
Condition score ................................. 7
Calf w eight .................................... 7
Annual Production per Cow ......................... 9
DISCUSSION ........................................ 10
SUMMARY ........................................ 10
LITERATURE CITED ................................. 11








INTRODUCTION
Crossbreeding of beef cattle has been widely used to achieve
improvements in beef production. The appropriate choice of breeds
in crossbreeding depends upon the additive genetic merit of the
breeds involved and heterosis resulting from the crossing of these
breeds. Information on average breed effects and heterosis levels in
various crosses thus are important to commercial producers.
This paper presents data on results from straightbreeding and
reciprocal crossbreeding of cattle of the Brahman, Charolais, and
Angus breeds. These breeds were selected for the study because of
their distinctive characteristics and availability for commercial
production in Florida and the southeastern United States. The
Charolais breed is noted for muscling and size; the Brahman for
adaptability to the subtropical environment and combining ability
with other breeds; the Angus for generally good fertility and carcass
quality. These breeds represent three divergent breed types of im-
portance in the United States. The Charolais represents the large
European beef breeds, the Brahman represents Bos indicus cattle
and the Angus represents cattle of British origin. The data presented
include those for reproductive performance, weaning traits of
calves, and annual production per cow.

MATERIALS AND METHODS
The research was conducted at the University of Florida
Agricultural Research Center, Ona, Florida, from 1963 to 1974. The
center is located 27o25' north latitude, 81'55' west longitude on
low-fertility, sandy soil. Average annual rainfall is 54 inches with
75% of the precipitation occurring between May and October. The
climate is semi-tropical with temperate intrusions during the
winter. These intrusions are characterized by repeated frost periods
with temperatures of 28to 34F, with lower temperatures occurring
at less frequent intervals.
The herds were maintained on improved grass pastures
composed predominately of Pangola digitgrass (Digitaria
decumbens), moderately fertilized. The cattle were supplemented
with 5 pounds of either molasses or citrus pulp-cottonseed meal (4:1
ratio) per head per day for approximately 90 days during late winter
and early spring.
The design used to produce straightbred and firstcross (F,)
progeny is shown in Table 1. Sires of each breed were exposed each
year to cows of each of the three breeds, in a balanced design. A total
of 27 sires were used in the project, nine for each of the three breeds.
Sires were selected subjectively to be representative of their breed.
Females were selected in a similar manner. Cows were culled from

1









Table 1. Number of matings by breed of sire and breed of dam.
Breed of sire
Breed of dam Angus Brahman Charolais Total
Angus 126 107 112 345
Brahman 118 128 121 367
Charolais 128 116 136 380
Total 372 351 369 1092

the herd annually for unsoundness or reproductive failure; herd
replacements averaged 19.6% per year. The mating season was
restricted to 90 days beginning in early March. Male calves were
castrated shortly after birth. Calves were weaned all at one time at
an average age of 222 days.
DATA ANALYSES
The criteria for evaluating reproductive performance were
pregnancy rate, calf survival rate, and weaning rate. Pregnancy rate
was expressed as the percentage of cows exposed to bulls which
were diagnosed pregnant by palpation in late August. Survival rate
was expressed as the percentage of pregnant cows which weaned
calves. Weaning rate was computed as the product of pregnancy
and survival rates.
Individual calf records were maintained for date of birth, sur-
vival, sex, age at weaning, weaning weight, estimated 205-day
weight, and condition score. Condition scores of 6, 7, and 8 were
used to designate low, medium, and high standard calves; 9 to 11,
good calves; and 12 to 14, choice calves. Average production per cow
was computed as the product of weaning weight x weaning rate.
Statistical analyses were performed by usual least squares
procedures as described by Harvey (2). The analyses shown in
Tables 2 and 3 appeared to be the most appropriate for this study.
The objective was to obtain unbiased estimates of breed-of-sire x
breed-of-dam subclass means. Year and age of dam (3 years, 4 years,
and mature) effects were included in the analyses for statistical pre-
cision. Significant levels between means were determined by the
standard t test (Peacock et al., 5; Peacock et al., 6).

EXPERIMENTAL RESULTS
The analyses of variance for reproduction and production
traits are shown in Tables 2 and 3, respectively. The means for re-
production traits are presented in Table 4 and those for production
traits in Table 5. Observed heterosis levels (percent advantage of
crossbreds over the average of parental breeds) are presented in


2









Tables 4 and 5. Breed of sire, breed of dam, and breed of sire x breed
of dam interaction were the items of primary interest in this study.

REPRODUCTION
Pregnancy Rate. The least squares mean for pregnancy rate
was 78.6%. Breed of sire had significant effects (P<0.05) on preg-
nancy rate, being lowest for Angus sires (74.4%), intermediate for
Charolais sires (79.1%) and highest for Brahman sires (82.3%). Pea-
cock et al. (7), at the same location, reported a pregnancy rate of 76%
for Brahman bulls vs 72% for Shorthorn bulls (P<0.05). Similar re-
sults were reported by Turner et al. (11) with cows mated to
Brahman bulls having the highest pregnancy rate and those mated
to Angus bulls the lowest. However, data reported by Crockett et al.
(1) from the Everglades area of south Florida showed that Angus
and Hereford bulls had higher calf crops than Brahman bulls.
Differences in pregnancy rate were not significantly in-
fluenced by breed of dam (Table 2). These results did not agree with
those of Crockett et al. (1), who reported birth rate for Angus cows to
be 88.7% as compared with 73.7% for Brahman cows. Research in
Louisiana (Turner, et al., 11), however, agreed with results from the
present study, showing Brahman cows to have a higher calving per-
centage (78.0%) than Angus (71.3%) or Hereford (72.8%) cows. Re-
search by Peacock et al. (7) on straightbreeding and reciprocal
crossing of the Brahman and Shorthorn cattle also showed a higher
average pregnancy rate for the Brahman cows, 71% vs.64% for
Shorthorns. In the present study, pregnancy rates for cows mated to
produce crossbred calves (77.1%) were slightly lower (P<0.10) than
those for cows mated to produce straightbred calves (81.5%).

Table 2. Mean squares from variance analyses of reproductive traits.
Degrees
of Pregnancy Survival Weaning
Source freedom rate rate rate b
Year 10 .9327** .0446
Age of dam 2 .7868** .2408**
Breed of sire (S) 2 .5632* .0352 32.68
Breed of dam (D) 2 .0019 .6345** 60.82*
SxD 4 .3039 .0780 56.09**
Within a .1480 .0485 16.06
df in error (1071) (842) (793)
a Shown in parentheses under error.
b Proximate analysis of mating group means (pregnancy rate x survival rate).
P<0.05
*P<0.01

3
















Table 3. Mean squares from variance analyses of weaning traits.
Age at Weaning 205-day Annual
Source IF weaning Condition weight weight prod/cow
Year 10 9277** 9.7** 236** 401** -
Sex 1 1345 38.4** 1447** 1583**
Age ofdam 2 6609** 10.7** 876** 290** --
Breed of sire 2 11742** 16.0** 2593** 1369** 534
Breed of dam 2 9988** 0.4 2877** 3501** 931*
SxD 4 595 17.7** 698** 691** 250
Within 795 861 1.4 44 21 289.5
"a From a proximate analysis of mating group subclass means (weaning rate x weaning weight).
P<0.05
P<0.01









Table 4. Least squares means for reproductive traits by mating groups.

Number
Group or of Pregnancy Calf Weaning
effect a matings rate survival rateb
Mu 1092 78.6% 94.3% 74.1%
1. AxA 126 79.2 92.6 73.3
2. BxB 128 84.3 94.3 79.5
3. CxC 136 81.1 96.1 77.9
4. AxB 118 69.6 97.6 67.9
5. BxA 107 83.0 87.0 72.2
6. AxC 128 74.4 96.2 71.6
7. CxA 112 73.7 86.5 63.8
8. BxC 116 79.5 98.5 78.3
9. CxB 121 82.5 99.6 82.2
Angus sires 372 74.4 95.5 70.9
Brahman sires 351 82.3 93.3 76.7
Charolais 369 79.1 94.1 74.6
Angus dams 345 78.6 88.7 69.8
Brahman dams 367 78.8 97.2 76.5
Charolais dams 380 78.3 96.9 75.9
Purebreds 390 81.5 94.3 76.9
Crossbreds 702 77.1 94.2 72.7
Advantage for crossmating
Ho(AB) 1/2(4 t5-1-2) -5.5 -1.2 -6.4
Ho(AC), 1/2(6 t7-1-3) -6.1 -3.0 -7.9
Ho(BC), 1/2(8 t9-2-3) -1.7 3.8 1.6
Advantage as percent of purebred average
Ho(AB) -6.7 -1.3 -8.4
Ho(AC) -7.6 -3.2 -10.4
Ho(BC) -2.1 4.0 2.0


CalfSurvival. Calf survival is an important factor affecting net
reproductive efficiency. Survival rate was influenced significantly
by breed of dam, but not by breed of sire (Table 2). The average sur-
"-vivarrate for all calves was 94.3% (Table 4). This value was lower
than that of 96.0% reported by Peacock et al. (7), but higher than the
92.0% observed by Turner et al. (11) or the 88.5% reported by Crock-
ett etal. (1).
Survival rates were 88.7%, 97.2%, and 96.9% (P<0.01), respec-
tively, for calves from Angus, Brahman, and Charolais dams (Table
4). There were no significant breed of sire x breed of dam interac-
tions. Mean survival rates were 87.0%, 86.5%, and 92.6%, respec-
tively, for Brahman x Angus, Charolais x Angus, and Angus x Angus
calves. Average survival rates for all straightbred and F, calves were
94.3% and 94.2%, respectively. Turner et al. (11) reported survival
rates of 80.5% for Brahman x Angus and 92.6% for Angus calves,


5









which were similar to the results obtained during this study. Sage-
biel et al. (10) reported significantly higher dystocia scores for
Angus cows than for Hereford and Charolais cows. Pahnish et al. (4)
reported no heterosis for birthweights of F, Angus x Charolais
calves, while reciprocal F, Charolais x Angus calves showed hetero-
sis levels of 4.6% and 5.1%, respectively, for males and females.
Weaning Rate. Weaning rate was computed as the product of
calving and survival rates. Breed of sire effects were nonsignificant.
Breed of dam effects were significant, and there was a highly signifi-
cant breed of sire x breed of dam interaction (Table 2).
The overall least squares mean for weaning rate was 74.1%.
Comparative rates by breed of dam were 69.8%, 76.5%, and 75.9%,
respectively, for Angus, Brahman and Charolais cows (Table 4). The
average values for reciprocal combinations were 70.0% for Angus-
Brahman, 67.7% for Charolais-Angus, and 80.2% for Charolais-
Brahman. Weaning rates were 76.9% for straightbred calves and
72.7% for F, calves.
The breed of sire x breed of dam interaction is of special inter-
est, since the merit of crossbreeding is determined by the additive
genetic merit of each breed plus that achieved through interaction
effects. The Charolais x Angus cross resulted in the lowest weaning
rate (63.8%) while the Charolais x Brahman cross was highest
(82.2%). The differences were due mainly to the relatively low sur-
vival rate for Charolais x Angus calves (86.5%) and high survival
rate (99.6%) for Charolais x Brahman crosses.
The advantages for crossmated groups over the mean of the
straightbred groups are presented in Table 4. Considering the three
characteristics measured as calf traits, heterosis was negative for
all breed combinations and traits except survival and weaning rate
for Brahman-Charolais crosses.

WEANING TRAITS
Age ofCalfat Weaning. When mating occurs in a restricted sea-
son and all calves are weaned at one time, age of calf at weaning be-
comes an important production trait influencing the weight of calf
at weaning. Consequently, age at weaning was analyzed as a pro-
duction trait in this study. The overall least squares mean for age at
weaning was 222.4 days.
A number of responses may influence this trait, including
length of gestation, interval from parturition to first estrus, aggres-
siveness and mating ability of bulls, and fertility of both males and
females once coupling is achieved.
Significant (P<0.01) differences in weaning age occurred for
breed of sire and breed of dam, with no significant breed of sire x

6









breed of dam interaction (Table 3). Age at weaning for straightbred
matings was 211'.4, 224.5, and 235.3 days, respectively, for
Brahman, Charolais, and Angus breeds. Breed of sire and breed of
dam effects, respectively, pooled over all groups, were 214.8 and
217.9 days from Brahman, 227.3 and 219.6 for Charolais, and 225.1
and 229-6for Angus bredsAge at weaning for crossbred calves was
intermediate between weaning ages of parent breeds with no indi-
cation of heterosis for this trait.
Positive effects on age at weaning by both Angus sires and
Angus dams suggest that length of gestation was an important fac-
tor in breed effects in this project. This indication is supported by
the report of Sagebiel et al. (9), showing a shorter gestation period
for the Angus than for the Charolais (279 vs 285 days), and a report
by Plasse et al. (8) showing gestation length (291 days) in the
Brahman breed to be considerably longer than those reported for
the British breeds.
Condition score. This trait is of interest because it is known to
be influenced by important factors, including breed characteristics,
general well-being of the calf, and maternal ability of the dam. Up
to the point of optimum degree of fatness there is a positive relation-
ship between condition score and market value.
The mean condition score was 9.6, slightly less than average
_go in terms of federal ade. Scores were influenced significantly
(P<0.01) by year, sex of calf and age of dam (Table 3). The condition
L s for straightbred calves were 8.9 for Brahman and 9.4 for
Angus and Charolais (P<0.05). Mean scores of breed of dam varied
only from 9.6 to 9.7 (Table 5). Mean scores by breed of sire were 9.4,
9.6, and 9.9, respectively for the Brahman, Charolais, and Angus
breeds (P<0.01). These differences are in agreement with the gen-
eral evaluation of these breeds with respect to the ratio of fat to lean.
Heterosis levels for each of the breed combinations were
highly significant, amounting to 9.8%, 5.5%, and 5.3%, respectively,
for the reciprocal Angus-Brahman, Charolais-Brahman, and Angus-
Charolais crosses. These results are in agreement with other reports
generally showing high levels of heterosis in Brahman-British
breed crosses (Koger et al., 3).
Calf Weight. The effects of the different variables on weaning
weight and estimated 205-day weight were almost identical. The re-
sults from weaning weight only, therefore, will be discussed. All var-
iables included in the model had highly significant effects on calf
weights (Table3).
The weaning weights of the straightbred groups were 390, 398,
and 519 pounds, respectively, for the Angus, Brahman, and Charo-
lais calves (Table 5). Weights of the crossbred groups varied from

7






Table 5. Least squares mating group means, and calf heterosis for weaning traits.

Mating a Number of Age at Weaning 205-day Production/
group observations weaning Condition weight weight Cow b
days score lbs lbs lbs
Mu 817 222.4 9.6 456 428 338
1. AxA 94 235.3 9.4 390 351 286
2. BxB 103 211.4 8.9 398 392 317
3. CxC 107 224.5 9.4 519 482 404
4. AxB 80 219.5 10.2 447 423 303
5. BxA 75 219.1 9.8 437 417 316
6. AxC 94 220.3 10.0 477 451 342
7. CxA 72 234.5 9.7 450 405 287
8. BxC 93 213.8 9.5 477 462 373
9. CxB 99 222.9 9.7 506 472 416
Angus sires 268 225.1 9.9 438 408 311
Brahman sires 282 214.8 9.4 437 424 335
o0 Charolais sires 294 227.3 9.6 492 453 367
Angus dams 241 229.6 9.6 426 391 297
Brahman dams 282 217.9 9.6 450 429 344
Charolais dams 294 219.6 9.7 491 465 373
Purebreds 304 223.7 9.2 436 408 336
Crossbreds 513 221.7 9.8 466 438 340
Heterosis in units of measurement
Ho(AB) 1/2 (4 t5-1-2) -4.0 0.9 48 48 9
Ho(AC) 1/2(6 t7-1-3) -2.5 0.5 9 11 -30
Ho(BC) 1/2(8 t9-2-3) 0.4 0.5 33 30 35
Heterosis as percent of purebred average
Ho(AB) -1.8 9.8 12 13 3
Ho(AC) -1.1 5.3 2 3 -9
Ho(BC) 0.2 5.5 7 7 10
"aBreed designation: A, B, and C indicate Angus, Brahman, and Charolais, respectively. Breed of sire shown first for mating
groups.
bWeaning rate x weaning weight.









506 pounds for C x B to 437 pounds for B x A calves. The average
weight for all crossbreds exceeded that for the straightbreds by 30
pounds, or 6.9%.
Heterosis levels were a highly significant 12% for A-B and 7%
for C-B but a nonsignificant 2% for A-C crosses. These results indi-
cate high levels of heterosis among crosses of the British and
Brahman breeds but only low levels from crossing the Angus and
Charolais breeds.

ANNUAL PRODUCTION PER COW
This trait is a measure of total production performance and is
highly correlated with total economy of beef cattle production. It is
a composite trait including genetic components for cow fertility,
growth potential of the calf, calf survival, and maternal ability of
the cow. Each of these components is in turn influenced by additive
breed and heterosis effects.
The mean annual production per cow was 338 pounds of calf at
weaning (Table 5). Of the nine breed-of-sire x breed-of-dam sub-
classes, the straightbred Angus group was the lowest with 286
pounds. This value was associated with the lowest weaning weight
and the lowest weaning rate. The largest annual production of 416
pounds was from Brahman cows mated to Charolais bulls. This pro-
duction level resulted from the highest weaning rate of 82% com-
bined with the second highest weaning weight of 506 pounds. These
values emphasize the impact of weaning rate on annual production
rate.
Annual production by sire breeds pooled over all breeds of
dams was 311, 335, and 367 pounds respectively for Angus,
Brahman, and Charolais sires. Comparable values by breed of dam
were 297, 344, and 373 pounds. These production levels parallel
breed size, as might be anticipated.
Heterosis levels for annual production were -9%, 3%, and 10%,
respectively, for Angus-Charolais, Angus-Brahman, and Brahman-
Charolais crosses. The low value for Angus-Charolais crosses was
associated with genetic size and growth potential of the Angus
breed and a high death loss among progeny of Charolais bulls mated
to Angus cows. These results emphasize the need for compatibility
in size of sires with that of dams to which they are mated, if high
death losses in calves are to be avoided.
The heterosis level of 3% for reciprocal Brahman-Angus
crosses resulted from a high level of heterosis for growth (12%) com-
bined with a negative heterosis (-8.4%) for weaning rate, once again
emphasizing the overriding importance of weaning rate in total
performance.

9









DISCUSSION
It should be noted that this report presents the results from the
first phase of a crossbreeding project designed to evaluate the
Angus, Brahman, and Charolais breeds as straightbreds and
crossbreds. The crossbred heifers evaluated during the first phase of
the project reported here will be carried forward into the second
phase of the project, where they will be evaluated as crossbred
dams.
-The most important results from the first phase of the project
Were the following. (1) Hybrid vigor levels vary widely with breed
combinations, as demonstrated by a heterosis level of 12% for wean-
ing weight in Brahman-Angus crosses but only 2% in Angus-
Charolais crosses. (2) Incompatibility in characteristics such as size
of fetus and size of cow can lead to disastrous results in unwise
breed combinations, as was demonstrated by mating Charolais
bulls to Angus cows in this trial. When the advantages for breed-
cross matings over straightbred matings were calculated for the
three reproductive traits, seven of nine of these differences were
negative (Table 4). These breed combinations might be used suc-
cessfully, however, where crossbred rather than straightbred cows
are used as dams. This point will be elucidated during the second
phase of the project, to be reported at a later date.

SUMMARY
Straightbred and reciprocal firstcross progeny of the Angus,
Brahman, and Charolais breeds were produced by mating sires and
females of the three breeds in all possible combinations in a ba-
lanced design. A total of nine sires of each breed were used over a
period of 11 years. The data from 1092 matings, resulting in 863
pregnancies, and 817 complete weaning records were analyzed.
Mean pregnancy rates were 81.5% for straightbred matings
and 77.1% for crossmatings (P<0.10). The effects of crossmating
were negative for all breed combinations but not significantly so for
the numbers involved. Pregnancy rates by breed of sire were 82.3%,
79.1%, and 74.4%, respectively, for Brahman, Charolais, and Angus
sires. Pregnancy rates by breed of dam were almost identical.
Calf survival was significantly influenced by breed of dam
(P<0.01). This result is explained on the basis of heavy death loss in
calves from Angus cows mated to either Brahman or Charolais bulls
(P<0.01) with heavy death losses apparently explained by difficult
birth. Except for Angus cows, weaning rate closely paralleled preg-
nancy rate.
Earliness of calving (determined by age of calf at weaning) was
negatively influenced by Brahman sires (P<0.01) and positively in-


10









fluenced by Angus dams. Heterosis effects for weaning age were
negligible.
Condition scores of calves were negatively influenced by
Brahman sires (P<0.01) and positively influenced by Charolais
dams. Heterosis effects were significantly positive for all breed
combinations, being 9.8%, 5.5%, and 5.3%, respectively, for Angus-
Brahman, Brahman-Charolais, and Angus-Charolais crosses.
Weaning weights were 492,438, and 437 pounds, respectively,
for C, A, and B sires (P<0.01) and 491, 450, and 426 pounds for C, B,
and A dams (P<0.01). Heterosis levels were 12%, 7%, and 2%, re-
spectively, for A-B, B-C, and A-C crosses. Annual production per cow
was strongly influenced by calf survival, resulting in low produc-
tion rates for Angus cows mated to either Charolais or Brahman
bulls.

LITERATURE CITED
1. Crockett, J. R., R. W. Kidder, M. Koger, and D. W. Beardsley. 1973. Beef
production in a crisscross breeding system involving the Angus,
Brahman, and Hereford. Fla. Agr. Exp. Sta. Tech. Bull. 759.
2. Harvey, W. R. 1975. Least-squares analyses of data with unequal sub-
class numbers. A.R.S. H-4 USDA.
3. Koger, M., F. M. Peacock, and J. R. Crockett. 1975. Heterosis effects on
weaning performance of Brahman-Shorthorn calves. J. Anim. Sci.
40:826.
4. Pahnish, O. F., J. S. Brinks, J. J. Wick, B. W. Knapp, and T. M. Riley.
1969. Results from crossing beef x beef and beef x dairy breeds: calf per-
formance to weaning. J. Anim. Sci. 28:291.
5. Peacock, F. M., J. R. Crockett, and A. C. Warnick. 1977. Reproductive
performance and crossbreeding Angus, Brahman and Charolais
cattle. J. Anim. Sci. 44:729.
6. Peacock, F. M., M. Koger, and E. M. Hodges. 1978. Weaning traits of
Angus, Brahman, Charolais and F, crosses of these breeds. J. Anim. Sci.
47:366.
7. Peacock, F. M., M. Koger, W. G. Kirk, E. M. Hodges, and A. C.
Warnick. 1971. Reproduction in Brahman, Shorthorn and crossbred
cows on different pasture programs. J. Anim. Sci. 33:458.
8. Plasse, D., A. C. Warnick, R. E. Deese, and M. Koger.
1968. Reproduction behavior of Bos indicus females in subtropical en-
vironment II. Gestation length in Brahman cattle. J. Anim. Sci. 27:101.
9. Sagebiel, J. A., G. F. Krause, Bob Sibbit, L. Langford, A. J. Dyer, and John
F. Lasley. 1973. Effect of heterosis and maternal influence on gestation
length and birth weight in reciprocal crosses among Angus, Charolais
and Hereford cattle. J. Anim. Sci. 37:1273.
10. Sagebiel, J. A., G. F. Krause, B. Sibbit, L. Langford, J. E. Comfort, A. J.
Dyer, and J. F. Lasley. 1969. Dystocia in reciprocally crossed Angus,
Hereford and Charolais cattle. J. Anim. Sci. 29:245
11. Turner, J. E., B. R. Farthing, and G. L. Robertson. 1968 Heterosis in re-
productive performance of beef cows. J. Anim. Sci. 27:336.

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Beef Production from Straightbreds and Reciprocal Crosses of Angus, Brahman, and Charolais Cattle December 1979 Bulletin 810 (technical) Agricultural Experiment Stations Institute of Food and Agricultural Sciences University of Florida, Gainesville F. A. Wood, Dean for Research AUTHORS F. M. Peacock, M. Koger, E. M. Hodges, J. R. Crockett, and A. C. Warnick Mr. Peacock is a Professor of Animal Husbandry at the Agricultural Research Center, Ona. Dr. Koger is a Professor of Animal Genetics in the Animal Science Department, Gainesville. Dr. Hodges is a Professor of Agronomy at the Agricultural Research Center, Ona. Dr. Crockett is an Associate Professor of Animal Genetics at the Agricultural Research and Education Center, Belle Glade. Dr. Warnick is a Professor of Animal Physiology in the Animal Science Department, Gainesville. INTRODUCTION Crossbreeding of beef cattle has been widely used to achieve improvements in beef production. The appropriate choice of breeds in crossbreeding depends upon the additive genetic merit of the breeds involved and heterosis resulting from the crossing of these breeds. Information on average breed effects and heterosis levels in various crosses thus are important to commercial producers. This paper presents data on results from straight breeding and reciprocal crossbreeding of cattle of the

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Brahman, Charolais, and Angus breeds. These breeds were selected for the study because of their distinctive characteristics and availability for commercial production in Florida and the southeastern United States. The Charolais breed is noted for muscling and size; the Brahman for adaptability to the subtropical environment and combining ability with other breeds; the Angus for generally good fertility and carcass quality. These breeds represent three divergent breed types of importance in the United States. The Charolais represents the large European beef breeds, the Brahman represents Bos indices cattle and the Angus represents cattle of British origin. The data presented include those for reproductive performance, weaning traits of calves, and annual production per cow. MATERIALS AND METHODS The research was conducted at the University of Florida Agricultural Research Center, Ona, Florida, from 1963 to 1974. The center is located 27' north latitude, 8155' west longitude on low-fertility, sandy soil. Average annual rainfall is 54 inches with 75% of the precipitation occurring between May and October. The climate is semi-tropical with temperate intrusions during the winter. These intrusions are characterized by repeated frost periods with temperatures of 28 to 34F, with lower temperatures occurring at less frequent intervals. The herds were maintained on improved grass pastures composed predominately of Pangola digitgrass (Digitaria decumbens), moderately fertilized. The cattle were supplemented with 5 pounds of either molasses or citrus pulp-cottonseed meal (4:1 ratio) per head per day for approximately 90 days during late winter and early spring. The design used to produce straightbred and firstcross (F1) progeny is shown in Table 1. Sires of each breed were exposed each year to cows of each of the three breeds, in a balanced design. A total of 27 sires were used in the project, nine for each of the three breeds. Sires were selected subjectively to be representative of their breed. Females were selected in a similar manner. Cows were culled from the herd annually for unsoundness or reproductive failure; herd replacements averaged 19.6% per year. The mating season was restricted to 90 days beginning in early March. Male calves were castrated shortly after birth. Calves were weaned all at one time at an average age of 222 days. Table 1. Number of matings by breed of sire and breed of dam. Breed of sire Breed of dam Angus Brahman Charolais Total Angus 126 107 112 345

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Brahman 118 128 121 367 charolais 128 116 136 380 Total 372 351 369 1092 DATA ANALYSES The criteria for evaluating reproductive performance were pregnancy rate, calf survival rate, and weaning rate. Pregnancy rate was expressed as the percentage of cows exposed to bulls which were diagnosed pregnant by palpation in late August. Survival rate was expressed as the percentage of pregnant cows which weaned calves. Weaning rate was computed as the product of pregnancy and survival rates. Individual calf records were maintained for date of birth, survival, sex, age at weaning, weaning weight, estimated 205-day weight, and condition score. Condition scores of 6, 7, and 8 were used to designate low, medium, and high standard calves; 9 to 11, good calves; and 12 to 14, choice calves. Average production per cow was computed as the product of weaning weight x weaning rate. Statistical analyses were performed by usual least squares procedures as described by Harvey (2). The analyses shown in Tables 2 and 3 appeared to be the most appropriate for this study. The objective was to obtain unbiased estimates of breed-of-sire x breed-of-dam subclass means. Year and age of dam (3 years, 4 years, and mature) effects were included in the analyses for statistical precision. Significant levels between means were determined by the standard t test (Peacock et al., 5; Peacock et al., 6). EXPERIMENTAL RESULTS The analyses of variance for reproduction and production traits are shown in Tables 2 and 3, respectively. The means for reproduction traits are presented in Table 4 and those for production traits in Table 5. Observed heterosis levels (percent advantage of crossbreds over the average of parental breeds)

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are presented in Tables 4 and 5. Breed of sire, breed of dam, and breed of sire x breed of dam interaction were the items of primary interest in this study. REPRODUCTION Pregnancy Rate. The least squares mean for pregnancy rate was 78.6%. Breed of sire had significant effects (P<0.05) on pregnancy rate, being lowest for Angus sires (74.4%), intermediate for Charolais sires (79.1%) and highest for Brahman sires (82.3%). Peacock et al.. (7), at the same location, reported a pregnancy rate of 76% for Brahman bulls vs 72% for Shorthorn bulls (P<0.05). Similar results were reported by Turner et al. (11) with cows mated to Brahman bulls having the highest pregnancy rate and those mated to Angus bulls the lowest. However, data reported by Crockett et al. (1) from the Everglades area of south Florida showed that Angus and Hereford bulls had higher calf crops than Brahman bulls. Differences in pregnancy rate were not significantly influenced by breed of dam (Table 2). These results did not agree with those of Crockett et al. ( 1), who reported birth rate for Angus cows to be 88.7% as compared with 73.7% for Brahman cows Research in Louisiana (Turner, et al., 11), however, agreed with results from the present study, showing Brahman cows to have a higher calving percentage (78.0%) than Angus (71.3%) or Hereford (72.8%) cows. Research by Peacock et al. (7) on straightbreeding and reciprocal crossing of the Brahman and Shorthorn cattle also showed a higher average pregnancy rate for the Brahman cows, 71% vs 64% for Shorthorns. In the present study, pregnancy rates for cows mated to produce crossbred calves (77.1%) were slightly lower (P
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Within a .1480 .0485 16.06 df in error (1071) (842) (793)aShown in parentheses under error.bProximate analysis of mating group means (pregnancy rate x survival rate). *P<0.05 **P<0.01 Table 3. Mean squares from variance analyses of weaning traits.Source IF Age at weaning Condition Weaning weight 205day weight Annual prod/ cowaYear 10 9277** 9.7** 236** 401** -Sex 1 1345 38.4** 1447** 1583** -Age of dam 2 6609** 10.7** 876** 290** -Breed of sire 2 11742** 16.0** 2593** 1369** 534 Breed of dam 2 9988** 0.4 2877** 3501** 931* S x D 4 595 17.7** 698** 691** 250 Within 795 861 1.4 44 21 289.5aFrom a proximate analysis of mating group subclass means (weaning rate x weaning weight).

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*P<0.05 **P<0.01 Calf Survival. Calf survival is an important factor affecting net reproductive efficiency. Survival rate was influenced significantly by breed of dam, but not by breed of sire (Table 2). The average survival rate for all calves was 94.3% (Table 4). This value was lower than that of 96.0% reported by Peacock et al. (7), but higher than the 92.0% observed by Turner et al. (11) or the 88.5% reported by Crockett et al. (1). Survival rates were 88.7%, 97.2%, and 96.9% (P<0.01), respectively, for calves from Angus, Brahman, and Charolais dams (Table 4). There were no significant breed of sire x breed of dam interactions. Mean survival rates were 87.0%, 86.5%, and 92.6%, respectively, for Brahman x Angus, Charolais x Angus, and Angus x Angus calves. Average survival rates for all straight bred and F1 calves were 94.3% and 94.2%, respectively. Turner et al. (11) reported survival rates of 80.5% for Brahman x Angus and 92.6% for Angus calves, which were similar to the results obtained during this study. Sagebiel et al. (10) reported significantly higher dystocia scores for Angus cows than for Hereford and Charolais cows. Pahnish et al. (4) reported no heterosis for birth weights of F1 Angus x Charolais calves, while reciprocal F1 Charolais x Angus calves showed heterosis levels of 4.6% and 5.1%, respectively, for males and females. Weaning Rate. Weaning rate was computed as the product of calving and survival rates. Breed of sire effects were nonsignificant. Breed of dam effects were significant, and there was a highly significant breed of sire x breed of dam interaction (Table 2). The overall least squares mean for weaning rate was 74.1%. Comparative rates by breed of dam were 69.8%, 76.5%, and 75.9%, respectively, for Angus, Brahman and Charolais cows (Table 4). The average values for reciprocal combinations were 70.0% for Angus Brahman, 67.7% for Charolais-Angus, and 80.2% for CharolaisBrahman. Weaning rates were 76.9% for straightbred calves and 72.7% for F calves. The breed of sire x breed of dam interaction is of special interest, since the merit of crossbreeding is determined by the additive genetic merit of each breed plus that achieved through interaction effects. The Charolais x Angus cross resulted in the lowest weaning rate (63.8%) while the Charolais x Brahman cross was highest (82.2%). The differences were due mainly to the relatively low survival rate for Charolais x Angus calves (86.5%) and high survival rate (99.6%) for Charolais x Brahman crosses. The advantages for crossmated groups over the mean of the straightbred groups are presented in Table 4. Considering the three characteristics measured as calf traits, heterosis was negative for all breed combinations and traits except survival and weaning rate for Brahman-Charolais crosses.

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Table 4. Least squares means for reproductive traits by mating groups Group or effectaNumber of matings Pregnancy rate Calf Survival Weaning rate b Mu 1092 78.6% 94.3% 74.1% 1. A x A 126 79.2 92.6 73.3 2. B x B 128 84.3 94.3 79.5 3. C x C 136 81.1 96.1 77.9 4. A x B 118 69.6 97.6 67.9 5. B x A 107 83.0 87.0 72.2 6. A x C 128 74.4 96.2 71.6 7. C x A 112 73.7 86.5 63.8 8. B x C 116 79.5 98.5 78.3 9. C x B 121 82.5 99.6 82.2 Angus sires 372 74.4 95.5 70.9 Brahman sires 351 82.3 93.3 76.7 Charolais sires 369 79.1 94.1 74.6 Angus dams 345 78.6 88.7 69.8 Brahman dams 367 78.8 97.2 76.5 Charolais dams 380 78.3 96.9 75.9 Purebreds 390 81.5 94.3 76.9 Crossbreds 702 77.1 94.2 72.7 Advantage for crossmating

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Ho(AB)c,1/2 (45-1-2) -5.5 -1.2 -6.4 Ho(AC), 1/2(67-1-3) -6.1 -3.0 -7.9 Ho(BC), 1/2(89-2-3) -1.7 3.8 1.6 Advantage as percent of purebred average Ho(AB) -6.7 -1.3 -8.4 Ho(AC) -7.6 -3.2 -10.4 Ho(BC) -2.1 4.0 2.0 aBreed designation:A, B, and C indicate Angus, Brahman, and Charolais, respectively. Breed of sire shown first for mating groups.bWeaning rate x weaning weight.cBreed combinations enclosed in parentheses include reciprocal matings combined. WEANING TRAITS Age of Calf at Weaning. When mating occurs in a restricted season and all calves are weaned at one time, age of calf at weaning becomes an important production trait influencing the weight of calf at weaning. Consequently, age at weaning was analyzed as a production trait in this study. The overall least squares mean for age at weaning was 222.4 days. A number of responses may influence this trait, including length of gestation, interval from parturition to first estrus, aggressiveness and mating ability of bulls, and fertility of both males and females once coupling is achieved. Significant (P<0.01) differences in weaning age occurred for breed of sire and breed of dam, with no significant breed of sire x breed of dam interaction (Table 3). Age at weaning for straightbred matings was 211.4, 224.5, and 235.3 days, respectively, for Brahman, Charolais, and Angus breeds. Breed of sire and breed of dam effects, respectively, pooled over all groups, were 214.8 and 217.9 days from Brahman, 227.3 and 219.6 for Charolais, and 225.1 and 229.6 for Angus breeds. Age at weaning for crossbred calves was intermediate between weaning ages of parent breeds with no indication of heterosis for this trait. Positive effects on age at weaning by both Angus sires and Angus dams suggest that length of gestation

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was an important factor in breed effects in this project. This indication is supported by the report of Sagebiel et al. (9), showing a shorter gestation period for the Angus than for the Charolais (279 vs 285 days), and a report by Plasse et al. (8) showing gestation length (291 days) in the Brahman breed to be considerably longer than those reported for the British breeds. Condition score. This trait is of interest because it is known to be influenced by important factors, including breed characteristics, general well-being of the calf, and maternal ability of the dam. Up to the point of optimum degree of fatness there is a positive relationship between condition score and market value. The mean condition score was 9.6, slightly less than average good in terms of federal grade. Scores were influenced significantly (P<0.01) by year, sex of calf and age of dam (Table 3). The condition scores for straightbred calves were 8.9 for Brahman and 9.4 for Angus and Charolais (P<0.05). Mean scores of breed of dam varied only from 9.6 to 9.7 (Table 5). Mean scores by breed of sire were 9.4, 9.6, and 9.9, respectively for the Brahman, Charolais, and Angus breeds (P
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days score lbs lbs lbs Mu 817 222.4 9.6 456 428 338 1. A x A 94 235.3 9.4 390 351 286 2. B x B 103 211.4 8.9 398 392 317 3. C x C 107 224.5 9.4 519 482 404 4. A x B 80 219.5 10.2 447 423 303 5. B x A 75 219.1 9.8 437 417 316 6. A x C 94 220.3 10.0 477 451 342 7. C x A 72 234.5 9.7 450 405 287 8. B x C 93 213.8 9.5 477 462 373 9. C x B 99 222.9 9.7 506 472 416 Angus sires 268 225.1 9.9 438 408 311 Brahman sires 282 214.8 9.4 437 424 335 Charolais sires 294 227.3 9.6 492 453 367 Angus dams 241 229.6 9.6 426 391 297 Brahman dams 282 217.9 9.6 450 429 344 Charolais dams 294 219.6 9.7 491 465 373 Purebreds 304 223.7 9.2 436 408 336 Crossbreds 513 221.7 9.8 466 438 340 Heerosis in units of measurement

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Ho(AB)c,1/2 (45-1-2) -4.0 0.9 48 48 9 Ho(AC), 1/2(67-1-3) -2.5 0.5 9 11 -30 Ho(BC), 1/2(89-2-3) 0.4 0.5 33 30 35 Heterosis as percent of purebred average Ho(AB) -1.8 9.8 12 13 3 Ho(AC) -1.1 5.3 2 3 -9 Ho(BC) 0.2 5.5 7 7 10aBreed designation:A, B, and C indicate Angus, Brahman, and Charolais, respectively. Breed of sire shown first for mating groups.bWeaning rate x weaning weight.cBreed combinations enclosed in parentheses include reciprocal matings combined. ANNUAL PRODUCTION PER COW This trait is a measure of total production performance and is highly correlated with total economy of beef cattle production. It is a composite trait including genetic components for cow fertility, growth potential of the calf, calf survival, and maternal ability of the cow. Each of these components is in turn influenced by additive breed and heterosis effects. The mean annual production per cow was 338 pounds of calf at weaning (Table 5). Of the nine breed-ofsire x breed-of-dam subclasses, the straightbred Angus group was the lowest with 286 pounds. This value was associated with the lowest weaning weight and the lowest weaning rate. The largest annual production of 416 pounds was from Brahman cows mated to Charolais bulls. This production level resulted from the highest weaning rate of 82% combined with the second highest weaning weight of 506 pounds. These values emphasize the impact of weaning rate on annual production rate. Annual production by sire breeds pooled over all breeds of dams was 311, 335, and 367 pounds respectively for Angus, Brahman, and Charolais sires. Comparable values by breed of dam were 297, 344, and 373 pounds. These production levels parallel breed size, as might be anticipated. Heterosis levels for annual production were -9%,3%, and 10%, respectively, for Angus-Charolais, Angus-Brahman, and Brahman-Charolais crosses. The low value for Angus-Charolais crosses was

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associated with genetic size and growth potential of the Angus breed and a high death loss among progeny of Charolais bulls mated to Angus cows. These results emphasize the need for compatibility in size of sires with that of dams to which they are mated, if high death losses in calves are to be avoided. The heterosis level of 3% for reciprocal Brahman-Angus crosses resulted from a high level of heterosis for growth (12%) combined with a negative heterosis (-8.4%) for weaning rate, once again emphasizing the overriding importance of weaning rate in total performance. DISCUSSION It should be noted that this report presents the results from the first phase of a crossbreeding project designed to evaluate the Angus, Brahman, and Charolais breeds as straightbred and crossbreds. The crossbred heifers evaluated during the first phase of the project reported here will be carried forward into the second phase of the project, where they will be evaluated as crossbred dams. The most important results from the first phase of the project were the following. (1) Hybrid vigor levels vary widely with breed combinations, as demonstrated by a heterosis level of 12% for weaning weight in Brahman-Angus crosses but only 2% in Angus-Charolais crosses. (2) Incompatibility in characteristics such as size of fetus and size of cow can lead to disasterous results in unwise breed combinations, as was demonstrated by mating Charolais bulls to Angus cows in this trial. When the advantages for breedcross matings over straightbred matings were calculated for the three reproductive traits, seven of nine of these differences were negative (Table 4). These breed combinations might be used successfully, however, where crossbred rather than straightbred cows are used as dams. This point will be elucidated during the second phase of the project, to be reported at a later date. SUMMARY Straightbred and reciprocal firstcross progeny of the Angus, Brahman, and Charolais breeds were produced by mating sires and females of the three breeds in aIl possible combinations in a balanced design. A total of nine sires of each breed were used over a period of 11 years. The data from 1092 matings, resulting in 863 pregnancies, and 817 complete weaning records were analyzed. Mean pregnancy rates were 81.5% for straightbred matings and 77.1% for crossmatings (P
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Earliness of calving (determined by age of calf at weaning) was negatively influenced by Brahman sires (P<0.01) and positively influenced by Angus dams. Heterosis effects for weaning age were negligible. Condition scores of calves were negatively influenced by Brahman sires (P<0.01) and positively influenced by Charolais dams. Heterosis effects were significantly positive for all breed combinations, being 9.8%, 5.5%, and 5.3%, respectively, for Angus-Brahman, Brahman-Charolais, and AngusCharolais crosses. Weaning weights were 492, 438, and 437 pounds, respectively, for C, A, and B sires (P<0.01) and 491, 450, and 426 pounds for C, B. and A dams (P<0.01). Heterosis levels were 12%, 7%, and 2%, respectively, for A-B, B-C, and A-C crosses. Annual production per cow was strongly influenced by calf survival, resulting in low production rates for Angus cows mated to either Charolais or Brahman bulls. LITERATURE CITED 1. Crockett, J. R., R. W. Kidder, M. Koger, and D. W. Beardsley. 1973. Beef production in a crisscross breeding system involving the Angus, Brahman, and Hereford. Fla. Agr. Exp. Sta. Tech. Bull.759. 2. Harvey, W. R. 1975. Least-squares analyses of data with unequal subclass numbers. A.R.S. H-4 USDA. 3. Koger, M., F. M. Peacock, and J. R. Crockett. 1975. heterosis effects on weaning performance of Brahman-Shorthorn calves. J. Anim. Sci. 40:826. 4. Pahnish, O. F., J. S. Brinks, J. J. Wick, B. W. Knapp, and T. M. Riley. 1969. Results from crossing beef x beef and beef x dairy breeds: calf performance to weaning. J. Anim. Sci. 28:291. 5. Peacock, F. M., J. R. Crockett, and A. C. Warnick. 1977. Reproductive performance and crossbreeding Angus, Brahman and Charolais cattle. J. Anim. Sci. 44:729. 6. Peacock, F. M., M. Koger, and E. M. Hodges. 1978. Weaning traits of Angus, Brahman, Charolais and F. crosses of these breeds. J. Anim. Sci. 47:366. 7. Peacock, F. M., M. Koger, W. G. Kirk, E. M. Hodges, and A. C. Warnick. 1971. Reproduction in Brahman, Shorthorn and crossbred cows on different pasture programs. J. Anim. Sci. 33:458. 8. Plasse, D., A. C. Warnick, R. E. Deese, and M. Koger. 1968. Reproduction behavior of Bos indicus females in subtropical environment II. Gestation length in Brahman cattle. J. Anim.

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Sci.27: 101. 9. Sagebiel, J. A., G. F. Krause, Bob Sibbit, L. Langford, A. J. Dyer, and John F. Lasley. 1973. Effect of heterosis and maternal influence on gestation length and birth weight in reciprocal crosses among Angus, Charolais and Hereford cattle. J. Anim. Sci. 37:1273. 10. Sagebiel, J. A., G. F. Krause, B. Sibbit, L. Langford, J. E. Comfort, A. J. Dyer, and J. F. Lasley. 1969. Dystocia in reciprocally crossed Angus, Hereford and Charolais cattle. J. Anim. Sci. 29:245 11. Turner, J. E., B. R. Farthing, and G. L. Robertson. 1968 Heterosis in reproductive performance of beef cows. J. Anim. Sci. 27:336. Back to the Publications Page


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