BULLETIN 436 AUGUST 1972

/

B URAR

SEP 2 81972

Crossbreeding British Bccf Breeds

Agricultural Experiment Station AUBURN UNIVERSITY
E. V. Smith, Director! Auburn, Alabama

CONTENTS
Page
EXPERIMENTAL PROCEDURE -------------4

A nalysis of data--RESULTS

-- -- -- -- -- -- -- ----

--

-- --

- 7
7

AND DISCUSSION -------------------------------

Pha se I -- - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - -- -- - 7 Pha se II-- - - - - - - - - - - - - - - - - - - - - -- - - -- - - - - - - - - - - ----- - - 15
S UM M A RY --- - - - -- - - - - - - - - - -- - - - - - - - - - - - - - - - - -- - - - - - --

LITERATURE

CITED ------------------------------------

A P PE N DIX - - - -- - -- - - - - - - - --- - - - - - - - - - - - - - - - - -- - ----- - - -2

3 2 25 7

FIRST

PRINTING

4M,

AUGUST

1972

Crossbreeding British Beef Breeds
J. C. COLLINS, T. B. PATTERSON, W. M. WARREN, and G. B. MEADOWS'

MUCH

OF

THE

CROSSBREEDING

of beef

cattle has been con-

ducted in the Southern United States. In the Gulf Coast Region,

Brahman bulls have been crossed with native and British breed cows for improved production and greater tolerance to heat and insects. British bulls have been mated with native cows for increased production and improved quality. Recently these high grade cows have been bred to British bulls of a different breed and occasionally the two-breed cross females from these matings have been mated to a third breed. Crossbred cattle have proven to be highly productive. Several workers have reported higher calving rates and a higher percentage calves weaned as a result of crossing British breeds (6, 20, 22, 23, 26). Temple et al. (22) and Turner et al. (23) showed that crossbred females weaned a higher percentage of calves than straightbred females. Many reports (6, 8, 9, 10, 15, 20, 24) showed that crossbred calves are heavier at birth than straightbred calves. Some (9, 24) have shown that three-breed calves were heavier at birth than either two-breed or purebreds. Crossbred calves from purebred cows have been shown to be heavier at weaning than purebred calves (6, 8, 9, 10, 15, 18, 19, 20). Reports (9, 24) also show the three-breed calves were heavier than either purebred or two-breed calves. Gaines et at. (6) found that three-breed calves out of purebred cows sired by crossbred bulls were heavier than straightbred calves.
'Former Instructor, Department of Animal and Dairy Sciences, now Leader, Extension Animal Science Department, Mississippi State University; Professor, Department of Animal and Dairy Sciences; Professor and Head, Department of Animal and Dairy Sciences; Assistant Professor, Department of Animal and Dairy Sciences.

4

ALABAMA

AGRICULTURAL EXPERIMENT STATION

Slaughter or feeder grades at weaning have not been significantly affected by crossbreeding (5, 6, 10, 20, 24). Previous results (3, 4, 11, 12, 15, 16, 25) indicated that crossbred calves gained faster from weaning to 15-18 months of age and had a heavier final weight and a higher weight per day of age. However, some specific crosses which were as heavy or heavier than straightbred calves at weaning gained slower post-weaning (1, 2, 12, 25). Differences in carcass traits between purebreds and crossbreds tend to be small and non-significant unless the traits are associated with weight (1, 2, 5, 7, 8, 13, 15, 24). This study was conducted to determine the effects of crossbreeding among the Angus, Hereford, and Shorthorn breeds on reproduction, growth, and carcass characteristics. EXPERIMENTAL PROCEDURE The data used in this study were obtained from performance records of cows assigned to crossbreeding research at Auburn University. These records began with calves born in the 1957-58 calving season and ended with the completion of the post-weaning performance test of steers born during the 1967-68 calving season. Data collected during this period were divided into two phases: Phase I: A 5-year period (1957 through 1961) in which purebred matings and all possible crosses were made among the purebred Angus, Hereford, and Shorthorn breeds. Phase II: A 7-year period (1961 through 1967) in which the following matings were made: (a) Angus bulls mated to Hereford, Shorthorn, HerefordShorthorn, and Shorthorn-Hereford cows. (b) Hereford bulls mated to Angus, Shorthorn, Angus-Shorthorn, and Shorthorn-Angus cows. (c) Shorthorn bulls mated to Angus, Hereford, Angus-Hereford, and Hereford-Angus cows. The foundation cows were from the purebred Angus, Hereford, and Shorthorn herds of Auburn University. Both the purebred and crossbred cows used in Phase II were females produced in Phase I. Bulls used were selected from the purebred herds of Auburn University or were purchased from other breeders. In Phase I, 24 females of each breed were used to produce the calf crop each year, Table 1. The first year, females of each breed were randomly assigned to sire sub-groups on the basis

CROSSBREEDING BRITISH BEEF BREEDS

5

of age, ancestry, and previous performance. In succeeding years, cows were reallotted. During the study, each cow was mated to bulls of all three breeds. Cows with poor calving records were removed from the experiment and replaced with cows that were similar in age, ancestry, and previous performance. The basic plan was to use two bulls of each breed per year, with each bull being bred to twice as many females of his own breed as to each of the other two breeds.
TABLE 1. EXPERIMENTAL DESIGN OF PHASE

I
Total No. 24 24 24 72

Breed of cows

Breed of bulls' Angus No. 12 6 6 24 Hereford No. 6 12 6 24 Shorthorn No. 6 6 12 24

Angus Hereford-Shorthorn---------------------...... Total
1Two

sires of each breed used each year.

All cows were maintained under practical conditions. During the winter months, cows were full fed grass hay and/or sorghum silage supplemented with 1 to 2 pounds of soybean or cottonseed meal daily. Summer pastures consisted of common bermuda, Coastal bermuda, and Dallisgrass. Clover or vetch furnished some early spring grazing in these pastures. Calves were not creep fed. During the 1957-58 calving season, the first calf was born on September 13, 1957, and the last calf on March 22, 1958. The calving season was gradually shortened until in 1961-62, it extended from September 29, 1961 to February 13, 1962. All cows were individually identified, and within 24 hours after birth all calves were ear tagged and dehorned if necessary. At this time, the following records were obtained: calving dates, dam number, dam weight, calf number, calf weight, and sex. Calving difficulties and death losses were noted. In 1957, male calves were castrated at approximately 180 days of age. In all succeeding years, they were castrated within 24 hours after birth. Calves were weaned at approximately 250 days of age. At this time, the following records were obtained: cow weight, calf weight, slaughter score for steers, and slaughter and breeder scores for heifers. As they were weaned, the steer calves were placed on permanent pasture until all calves were weaned. At least 2 weeks

6

ALABAMA AGRICULTURAL

EXPERIMENT STATION

were allowed for adjustment after weaning the youngest calf before the post-weaning performance feeding began. While on post-weaning performance test, they were full-fed a 30 per cent roughage ration. Steers were slaughtered when visual appraisal indicated the group had obtained an average grade of USDA Choice. At slaughter, records were obtained for chilled carcass weight, fat thickness, rib eye area, conformation score, and USDA quality grade. Beginning in 1959, a wholesale rib was obtained and a tenderness score was determined by the Warner-Bratzler shear on a steak taken at the 12th rib. The experimental design of Phase II showing the matings made and the total number of cows used during the 7-year period is given in Table 2. In this phase, the management practices and records taken for the cows and calves up to weaning were the same as in Phase I. Both the purebred and crossbred cows used were produced in Phase I. No purebred calves were produced in Phase II, and all possible crosses (including reciprocal matings) were made among the three pure breeds. In addition, the two-breed cows were mated to bulls of a third breed. This allowed comparisons of two-breed and three-breed crosses.
TABLE 2. EXPERIMENTAL DESIGN OF PHASE

II Seven-year total No. 99 100 96 119 126 117 657

Breed of cows Angus No. 0 50 48 0 126 0 224

Angus Hereford Shorthorn Ax H and H xA-------H x S and S x H------S -SxAand A x S Seven-year total-------1 Two

Breed of bulls Hereford No. 50 0 48 0 0 117 215

1

Shorthorn No. 49 50 0 119 0 0 218

bulls of each breed used each season.

Steers produced in Phase II were placed on post-weaning performance test immediately after weaning with no adjustment period allowed. In addition to the carcass data collected in Phase I, marbling scores and per cent kidney fat were taken beginning in 1962. This made it possible to use the revised USDA quality grades and to calculate USDA yield grades. The steers were individually removed from test and slaughtered when they reached approximately 1,000 pounds.

CROSSBREEDING

BRITISH BEEF BREEDS

7

Analysis of Data

The breeds of cattle used in these experiments were not random samples of their breeds since they were selected from the existing herds of Angus, Hereford, and Shorthorn beef cattle at Auburn University. Analyses were made to compare appropriate breeding-group means to determine (1) the effect of crossbreeding on reproductive performance of the brood cows; (2) heterotic effects on pre-weaning, post-weaning, and carcass traits of the calves; and (3) the performance of the three breeds in crosses. In Phase I, appropriate comparisons were made between purebred and two-breed calves and among calves grouped by breed of bulls and cows. In Phase II, comparisons were made between two-breed and three-breed calves and between calves from purebred and two-breed cows. The data were analyzed by the method of least-squares (14). Separate analyses were made for birth weight, average daily gain from birth to weaning, weight at 250 days of age, and condition score using the linear model shown in the Appendix. The Chi-square method was used as the test of significance for differences in reproductive performance (21). Kramer's (17) modification of Duncan's multiple range test was used to test significance between individual means. RESULTS AND DISCUSSION
Phase I

Reproductive performance of the cows, expressed as percentages of calves born and weaned per cow bred, is shown in Table 3. A significantly higher (P<0.05) percentage of the Angus cows gave birth to and weaned calves than did either the Hereford or Shorthorn cows. The percentage of calves born dead or dying prior to weaning was slightly over 5 per cent for each of the three breeds of cows. The percentage of calves weaned was low for all breeds of cows for the calving season of 1960. During the 1959-60 calving and breeding season, all cows were fed Coastal bermudagrass hay ad libitum. A possible energy deficiency may have contributed to the poor reproductive performance. Cows bred to produce purebred calves gave birth to and weaned approximately 5 per cent more calves than did cows bred to produce crossbred calves, Table 4. This difference was not

8

ALABAMA AGRICULTURAL EXPERIMENT STATION
TABLE 3. REPRODUCTIVE PERFORMANCE BY BREED OF Cow, PHASE

I

Angus Year Cows Calving No. 24 24 24
-24

Hereford

Shorthorn

Pct.

19571958195919601961Total or

24

87.5 87.5 91.7 70.8 91.7

WeanWeanWeaning Cows Calving ing Cows Calving ing calves calves Calves Put. Pct. Pct. No. No. Pct. Pct. 23 73.9 65.2 83.3 75.0 75.0 24 24 87.5 83.3 24 79.2 70.8 79.2 58.3 54.2 78.3 24 87.5 23 82.6 24 70.8 62.5 24 58.3 58.3 66.7 66.7 24 75.0 70.8 91.7 24 70.8
74.8b 69.7b

average- ------------120 85.8a 80.Oa 119
1Means

119

73.lb

67.2b

followed by different letters differ at P<0.05.
REPRODUCTIVE PERFORMANCE OF PUREBRED Cows PRODUCING PUREBRED OR CROSSBRED CALVES, PHASE I

TABLE

4.

Year

Cows No.

Purebreds mating Calving WaigCw Waleanig
Pct. Pct.

Crossbreds mating
ows No. Calving Waleann
Pct. Pct.

1957__________________
1958___________________ -1959-------_

Total or average ______

--------1960__________________ --1961____ ----

_

_

35 37
36

88.6 91.9
77.8

77.1
83.8
72.2

36 35
35

75.0 77.1
77.1

66.7 71.4
74.3

36
36

63.9
80.1

63.9
77.8

36
36

69.4
77.8

69.3
72.2

180 1_____ 80.6

75.0

178

75.8

70.2

significant. Some published reports have indicated improved reproduction by cows bred to produce crossbred calves compared to cows bred to produce purebred calves (6, 8, 16, 26). Among the purebreds, the Hereford and Shorthorn calves were significantly (P<0.01) heavier at birth than were the Angus calves, Table 5. However, the Angus and Hereford calves had a higher average daily gain (P<0.05) and a heavier 250-day weight (P<O.05) than the Shorthorn calves. There were no significant differences among weaning scores of the purebred calves. Differences in the birth weights of Hereford x Shorthorn and Shorthorn x Hereford calves were not significant. However, these two were significantly heavier at birth (P<0.05) than any of the other groups of calves. No significant differences existed among 250-day weights of the Hereford x Shorthorn, Shorthorn x Angus,
and Shorthorn x

Shorthorn calves were heavier at 250 days of age (P<0.05) than the Hereford x Angus, Angus x Shorthorn, and Angus x Here-

Hereford

calves.

However, the Hereford x

CROSSBREEDING
TABLE

BRITISH

BEEF BREEDS
PHASE

9

5.

LEAST-SQUARES MEANS FOR PREWEANING PERFORMANCE,

1

250-day 250-day 250-day Weaning Birth weight ADG WDA weight score Lb. Lb. Lb. No. Lb. 9.9ab 1.78b 445b 59.Scd 1.54b 49 A x A____---------------------------9.Th 1.79b 448b 66.7b 41 H x H_______________________________ 1.52b 417c 9.4b 1.67c 42 66.Ob S x S________________________________ 1.41c 9.3b 445b '63.Sbcd 1.53b 15 A x H-------------------------------- 1.78b 9.4b 441b 60.lcd 1.52b 19 A x S--------------------------------- 1.76b 464b 1O.a 1.6Oab 22 63.6bcd H x A-------------------------------- 1.86ab 10.6a 1.96a 490a 73.7a 1.67a 19 H x S______________________________ 471ab 10.2ab 1.63ab iS ab 25 63.7bcd S x A-------------------------------iS8ab 470ab lO.ab 70.4ab 20 S x H________________________________ 1.60ab Breeding of calf Calves
1 Means

2 Grade

followed by different letters differ at P< 0.05. code: 9 - low Good; 10 = average Good; 11

high Good, etc.

ford. There were small but significant (P<0.05) differences in x Shortweaning scores. The Hereford x Angus and horn calves had the highest grades (10.6) and the Angus x Hereford the lowest (9.3). This difference represents slightly more than one-ninth of a grade. Comparisons of pre-weaning traits of the reciprocal crosses with mid-parent averages are shown in Table 6. There was little evidence of heterosis in birth weight. Only the difference between the Hereford x Shorthorn reciprocal crosses and the mid-parental average was significant (P<0.01). Gregory et al. (10, Gaines et al. (6) and Rollins et al. (20 also reported greater heterosis for birth weight from the Hereford and Shorthorn crosses than from crosses of Angus and Hereford or Angus and Shorthorn. Average daily gains from birth to weaning and 250-day weights were greater for crossbred than for straightbred calves in all comparisons, Table 6. The differences of 0.10 pound in average daily gain and 27 pounds in weaning weight between the crossbred and the straightbred calves were highly significant (P<0.01). In individual comparisons, the heterotic effects for these traits were greater for the Hereford x Shorthorn reciprocals than for the other two crossbred combinations. The greater heterosis in

Hereford

Hereford x Shorthorn crosses reported here
the

agrees with findings

of Gregory et al. (10) and Rollins et al. (20). Differences in weaning scores were small and, for the most part, non-significant. However, the difference of 0.7 between age was highly significant (P<0.01). In addition, the difference of 0.3 between all crossbreds and all straightbreds was significant

Hereford x Shorthorn reciprocals

and the mid-parental aver-

10
TABLE 6.

ALABAMA AGRICULTURAL EXPERIMENT

STATION

LEAST-SQUARES MEANS AND DIFFERENCES OF PREWEANING TRAITS, PHASE I

Breeding of calf H xA & A x H-------------------------------H and A'-------------------------------------Difference-----------------------H xS& SxH _-----------------_-----------H and S2-----------

Calves No. 37 90 39 83

Birth weight Lb. 63.5 63.1 0.4 72.1
66.4

Difference----------------------A x S & Sx A---------------------------------44 62.2 A and 5'-------------------91 62.8 Difference------------------------------0.6 All crossbreds ---------------------------------120 65.9 1.59 464 10.0 All straightbreds -------------------------------- 132 64.1 1.49 437 9.7 Difference-----------------------------1.8 0.10

5.7

250-day 250-day Weaning ADG weight score Lb. Lb. 1.57 455 10.0 1.53 447 9.8 0.04 8 0.2 1.64 480 10.3 1.47 433 9.6 0.7 * 1.58 456 9.8 1.48 481 9.7 0.10 25** 0.1

0.17

47

27-

0.3*

1Grade code: 9 = low Good; 10 = average Good; 11
2
*

Mean of parental breeds.
P<0.05.
"P<0.01.

high Good, etc.

at the 0.05 level of probability. These differences represent approximately one-fourth and one-ninth of a grade, respectively. Calves by Hereford sires had significantly higher (P<0.05)
average daily gains, 250-day weights, and weaning scores than

calves by Angus and Shorthorn sires, Table 7. Angus cows produced calves that grew faster and had heavier weaning weights and higher weaning scores than calves produced by either the Hereford or Shorthorn cows. This is in general agreement with the report of Gregory et al. (10).
Post-weaning

performance

data for heifers are presented in

Table 8. No significant differences were found among breed of
TABLE 7. LEAST-SQUARES MEANS FOR BREED OF SIRE AND BREED OF DAM,

PHASE I1

Cavs Birth 250-day Cavsweight ADG Lb. Lb. No. Breed of sire Angus Hereford-Shorthorn Breed of dam
Angus-----------------

250-day 250-day Weaning WDA weight score' Lb. Lb. 1.77b 1.87a
1.81b

83 82
87

61.6b 68.Oa
66.7a

1.53b 1.60a iS5ab 1.60a iS55ab

44.3b 9
46 a 454b 463a 454b 449b

9.5b

10.3a 9.9b 10.2a 9.7b 9.8b

Hereford --------------

96
76

62.4b 4
67. a

1.85
1.82

1.80 66.6a 1.53b 80 Shorthorn _-----------1 Means followed by different letters differ at ' Grade code: 9= low Good; 10 = average Good; 11 = high Good, etc.

P<0.05.

CROSSBREEDING

BRITISH

BEEF

BREEDS

11
PERFORMANCE OF HEIFERS,

TABLE 8.

LEAST-SQUARES MEANS FOR POSTWEANING

PHASE

1I

Breed of heifer

Heifers No.

Pasture period WeanFinal ing 2 Period weight weight Lb. 419 444 404 407 422 447 460 458 463 Days 103 89 107 95 95 103 94 81 98 Lb. 464b 476b 461b 466b 475b 496ab 506ab 495ab 528a Final ADG weight Lb. 0.42 0.42 0.44 0.67 0.56 0.51 0.53 0.46 0.35 Lb. 682b 714ab 683b 691b 697b 728ab 739ab 717ab 765a

Feedlot period ADG Lb. 1.70 1.85 1.73 1.76 1.73 1.80 1.82 1.73 1.85 Final WDA Age

AxA____________. 27 H x H___________. 17 S x S_____________ 18 9 A x H____________ Ax S_____________ 12 10 Hx A___________xA H x S-........ 9 SxA_____________ 8 Sx H____________. 8

Lb. Days 1.42b 481 1.53ab 467 1.45ab 475 1.46ab 473 1.47ab 473 1.51ab 482 1.59a 471 1.57a 462 1.61a 475

1 Means followed by different letters differ at P<0.05. 7 days of age. 2 Unadjusted weaning weight at 250 ±

calf for average daily gain during either the pasture or feedlot periods. However, as shown in the comparisons in Table 9, crossbred heifers gained as fast or faster than straightbred heifers. The differences in final weights between reciprocal crosses and their respective mid-parent average were positive for all comparisons. Hereford x Shorthorn reciprocal crosses showed the greatest difference (53 pounds) and the Hereford x Angus reciprocal crosses the least difference (12 pounds) in final weight. The difference for the Angus x Shorthorn reciprocals was 24 pounds. The combined effect of heavier weaning weight and slightly faster growth rate after weaning resulted in crossbred heifers being 30 pounds heavier than the straightbred heifers at the end of the feedlot period. Least-squares means for post-weaning performance of steers are shown in Table 10. No significant differences among breed of calves existed in average daily gain on pasture. During the feedlot period, the Shorthorn x Hereford and reciprocal cross steers gained significantly faster (P<0.05) than the Shorthorn x Angus and the straightbred Angus steers. No significant differences in rate of gain during the feedlot period were found among any other breed groups. All groups of crossbred steers gained more rapidly than straightbred steers during both the pasture and feedlot periods, Table 11. When compared to the mid-parent average, Hereford x Shorthorn and reciprocal cross steers had the greatest advantage (111 pounds) in final weight and Hereford x Angus and recipro-

12

ALABAMA

AGRICULTURAL

EXPERIMENT

STATION

12

ALABAMA

AGRICULTURLEPRMN

TTO

TABLE 9. LEAST-SQUARES MEANS AND DIFFERENCES FOR HEIFERS, PHASE I

Breed of heifers Heifers weight 250-day Pasture Feedlot Birth weight ADG ADG No. Lb. Lb. Lb. Lb. HxA&Ax H______ 19 63.3 431 0.59 1.78 H and A---------------44 61.7 438 0.42 1.78 Difference ------- 1.6 ____ -7 0.1744 0.00 HxS&Sx H______ 17 69.7 461 0.44 1.84 H and S1______________ 66.8 35 438 0.43 1.79 Difference ____ 2.94 230 0.01 0.05 AxS&SxA________ 20 61.1 438 0.51 1.73 A and S1________________ 61.8 45 424 0.43 1.72 Difference ____ -- 07 0.-----14* 0.084 0.01 All crossbreds------ 56 64.7 445 0.51 1.78 All straightbreds__. 62 63.4 433 0.43 1.76 Difference ____ 1.3 12* 0.080 0.02

Final weight Lb. 710
698
12

Final WDA Lb. 1.49
1.48
0.01

------------

752 699
5344

1.60 1.49
0.11

4

----

707 683
2440

1.52 1.44
0.08**

723
693
30**

1.54
1.47
0.07"

------------

1 Mean
*

of parent breeds.

** P<0.01.

P<0.05.

TABLE 10. LEAST-SQUARES MEANS FOR POSTWEANING PERFORMANCE OF STEERS, PHASE I'

Pasture period Steers WeanFinal ing Period weight weight No. Lb. Days Lb. AxA____________ 17 458 86 496bc Hx H___________ 431 22 89 489bc S S-----------20 418 103 461bc Ax H__________ 5 450 102 523ab Ax S__________ 7 446 97 506bc H x A_-____12 480 106 S3Oab Hx 10 499 102 558a S xA______17 479 112 SS0ab S xH_______ 12 472 89 538ab Breed of steers

Feedlot period ADGw Lb. Lb. 0.37 906b 0.60 911b 0.38 899b 0.63 956ab 0.61 958ab 0.43 9S5ab 0.56 1,024a 0.62 969a 0.64 1,008a ADG W Age Days 561 554
577

Lb. Lb. 1.83b 1.62b 1.96ab 1.65b
1.96ab 1.56b

1.92ab 2.Olab 1.9lab 2.07a 1.86b 2.l0a

1.66b 1.67b 1.64b 1.78a 1.65b 1.80a

576 571 581 576 586 564

'Unadjusted

1'Means followed by different letters differ at P<0.05. weaning weight at 250 ± 7 days of age.

cal steers the least (47 pounds). With the combined effects of heavier weaning weights and more rapid post-weaning gains, the average final weight of all crossbred steers was 73 pounds heavier than the average final weight of all straighthred steers.

are (6, 10, 25). other investigators
These results weight

in general agreement with these reported by

The greatest differences in steer carcass traits were among those associated with growth rate, carcass weight, and carcass were significantly (P<O.05) heavier than those of the straight-

per

day of age, Table 12. The crossbred steer carcasses

CROSSBREEDING BRITISH BEEF BREEDS
TABLE 11. LEAST-SQUARES MEANS FOR STEERS PERFORMANCE, PHASE I

13

Birth 250-day Pasture Feedlot weight weight ADG ADG No. Lb. Lb. Lb. Lb. 63.7 479 0.53 1.92 HxA&Ax H_________ 17 1 1.90 39 64.5 455 0.49 H and A Difference_______________ -0.8 24* 0.04 0.02 HxS&Sx H_________ 22 74.4 495 0.60 2.09 H and S1______________ 66.0 42 427 0.49 1.96 0.13* 8.4*0 680 0.110 Difference_______________ ____ AxS&Sx A_________ 24 63.2 474 0.62 1.94 1.90 37 63.8 438 0.38 A and S1__________________ Difference_______________ -0.6 360* 0.240 * 0.04 All crossbreds ________. 63 67.1 482 0.58 1.98 All straightbreds----- 59 64.7 440 0.45 1.92 Breed of steers Steers

------------------

Final weight Lb. 956
909 4740

Final WDA Lb. 1.65
1.64

1,016 905 111* 964 903
61*

0.01 1.79 1.61 0.18*0 1.66 1.59
0.07*

978
905
73 * 0

1.70
1.61

Difference
1 *P<0.05.

-

2.4*

42"

0.13*0

0.06

0.09*

Mean of parent breeds.

TABLE 12. LEAST-SQUARES MEANS OF STEER CARCASS CHARACTERISTICS, PHASE 11

Breed of

steesers

Steer

Carcass Dressing Carcass
weight per cent'

WDA

thickIn. 0.67 0.66
0.57

tk

ieeQulit
area'

grade

4

Tendersrness
5

Ax A______
H x H_____
SxS-

No. 17 22
20

Lb.
557c

540c
544c

Pct. 61.7ab 59.8c
60.bc

Lb. 0.99b 0.98b
0.94b

Sq. In. 11.3 11.1
11.1

13.3a

11.4b
12.6b

13.9 16.7

9

7

Ax H______ Ax S______

17.(
6

1.O4ab 0.77 1.O3ab 0.67 HxA_ lO0b 0.68 lil1a 0.66 636a 61.9a H x S------ 10 0.67 S xA_______ 17 S9Sab 61.Oabc l.01b S xH_______ 12 617ab 61.lab 1.i0a 0.65 Means followed by different letters differ at P<0.05. 5 7 12 597ab 591ab 582b 61.7ab 61.6ab 60.9ab
2'Regressed on weight. Regressed on carcass weight. 10 average Good; 11

10.3 11.4 11.9
11.5

12.5b 12.9b 12.3b
12.8b

17.2 20.3 15.7
2 3 7

15.9

9

11.5 11.5

13.5a 12.6b

15.3 151!
3

5

live

'Warner-Bratzler shear values-lower values more tender.

Grade code:

high Good; 12

low Choice, etc.

bred steers. When regressed on weight, dressing percentages of straightbred Herefords were significantly lower than those of the Angus or any of the crossbreds. There were slight differences among carcass quality grades. However, these steers were slaughtered when it appeared the group would have an average grade of USDA Choice. When regressed on carcass weight, no significant differences were found among fat thickness measurements, ribeye areas, or tenderness scores. These results are similar to those reported by Gregory et al. (12) and

live

Gaines et al. (7).

14

ALABAMA

AGRICULTURAL

EXPERIMENT

STATION

14
TABLE 13.

ALABAMA

GRICULTURLEPRMN

TTO

LEAST-SQUARES MEANS AND DIFFERENCES OF STEER CARCASS CHARACTERISTICS, PHASE I

Breed of steers

Carcass Dress-CarCass Steers weight ing WDA per cent No. Lb. Pct. Lb.
590 61.3 1.02

Fat Ribeye h area gad nessr In. Sq.In.
0.72
0.67

1

Tenderscore
16.5
15.3

AxH&Hx A ________ 17
A and

Difference_______________ ____ 0.5 0.04*0 0.05 -0.1 HxS&Sx H_________ 22 627 61.5 1.10 0.65 11.5 60.2 0.96 0.62 11.1 H and 5_______________ 42 542 0.4 Difference ______________ 850' 1.3 0.14** 0.03 AxS&SxA___________ 24 593 61.3 1.02 0.67 11.5 A and S3_________________ 37 551 61.1 0.96 0.62 11.2 Difference_______________ ____ 42*0 0.2 0.06* 0.05 0.3 All crossbreds------63 603 61.4 1.05 0.68 11.4 All straightbreds 59 547 60.7 0.97 0.63 11.2 Difference _____________ ____ 5600 0.7 0.0800 0.05 0.2 1Grade code: 12 =- low Choice; 13 = average Choice. 2Warner-Bratzler shear values-lower values more tender. ' Mean of parent breeds. 44 P<0.01.

39 549 60.8 0.98 H -------------

11.1
11.2

12.4
12.4

41*

0.0

-1.2

12.7 12.0
0.7

15.7 17.2
1.5

13.2 13.0 0.2 12.7 12.4
0.3

17.8 15.8 -2.0 16.7 16.1

-0.6

TABLE 14. LEAST-SQUARES MEANS BY SIRE AND BY DAM FOR STEER CARCASS CHARACTERISTICS, PHASE I'

Dress- CarcassFt Steers Carcass ing weight WDA ness per cent Lb. In. Lb. Pct. No.

Ribeye Quality Tendergrade ness area score Sq.In. 11.3
11.5

Breed of sire Angus____________________
Hereford

29
44

583
588

61.6
60.9

1.03
1.03

0.68
0.66

13.Oa
12.lb

17.1
16.1

Shorthorn________ 49 586 60.9 1.02 0.63 Breed of dam Angus___________ 46 581 61.2 1.01 0.67 Hereford_________ 39 586 60.9 1.04 0.66 Shorthorn________ 37 590 61.4 1.03 0.64 Means followed by different letters differ at P<0.05.

11.3 11.6 11.1 11.4

12.7a 12.8a 12.2b 12.8a

16.1 15.0 16.5 17.8

Least-squares means of carcass traits and the difference between straightbreds and crossbreds are shown in Table 13. Only those traits directly related to growth, carcass weight, and carcass weight per day of age were significantly different (PKO.O1).
More heterosis was expressed in

Hereford-Shorthorn

crosses than

in the Angus-Hereford and Angus-Shorthorn crosses. These results agree with those of Gaines et al. (6), Gregory et al. (13), and Rollins et al. (19). No significant heterotic effects were found for the other carcass traits measured.

CROSSBREEDING

BRITISH

BEEF

BREEDS

15

CROSSBRE EDING

BRITISH BEEF BREEDS

1

Differences existed amongthe carcass quality grades with carcasses from steers by either a Hereford bull or from a Hereford cow having significantly (P<O.05) lower carcass grades than those of the other breeds, Table 14. Phase II Among the purebred cows bred to produce crossbred calves, a higher percentage of the Angus cows calved than either the Hereford or Shorthorn cows, Table 15. However, there were no significant differences among purebred cows in the percentage of calves weaned since the Hereford and Shorthorn cows raised a higher percentage of calves that were born.
TABLE

15.

REPRODUCTIVE PERFORMANCE OF

Cows,

PHASE

IF

Angus Year

Hereford

Shorthorn

WeanWeanWeanCows Calving ing Cows Calving ing Cows Calving ing calves calves calves No. Pet. Pet. No. Pct. Pct. No. Pct. Pct. 1961__________ 3 66.7 66.7 7 85.7 85.7 6 66.7 33.3 72.7 72.7 7 71.4 57.1 1962__________ 8 100.0 75.0 11 1963______-____ 14 57.1 42.9 12 50.0 50.0 13 92.3 84.6 1965__________ 1966__________ 1967___________ Total or average_______

1964----------

18

74.5

66.7

14

85.7

85.7

14

42.9

42.9

20 18 18 99
(Ax

80.0 77.8 94.4 79.8b 100.0 100.0 58.3 81.3 29.6 50.0 80.0 62.2d

75.0 72.2 88.9

20 18 18

60.0 50.0 88.9 69.Ocd 87.5 54.5 86.7 100.0 91.7 82.6 90.9 86.3a

60.0 50.0 88.9

21 18 17

76.2 55.6 94.1 71.9c 88.9 81.8 93.3 84.2 60.9 75.0 84.0 78.7b

76.2 50.0 88.2 65.6cd 88.9 72.7 93.3 84.2 60.9 70.8 80.0 76.4b

70.7bc 100 100.0 100.0 50.0 68.8 29.6 46.2 80.0 8 11 15 14 24 23 22

69.Obc 94 87.5 54.5 86.7 92.9 91.7 78.3 90.9 9 11 15 19 23 24 25

H) &(H xA)

(AxS)-&(SxA)

(HxS)&(SxH)

1961__________ 5 1962__________ 8 1963_________ 12 1964__________ 16 1965__________ 27 1966__________ 26 1967__________ 25 Total or average ______________119

58.8d 117

84.6a 126

'Means followed by different letters differ at P<0.05.

Among the crossbreds, the Angus-Shorthorn cows dropped and weaned a significantly (P<O.05) higher percentage of calves than either the. Angus-Hereford or Hereford-Shorthorn cows.
The

Hereford-Shorthorn

cows calved and weaned a significantly

(P<O.05) higher percentage of calves than did the Angus-Hereford cows. Comparisons of reproductive performance between all cross-

16

16 ALABAMA AGRICULTURAL EXPERIMENT STATION

bred and all purebred cows showed that crossbred cows calved 1.6 and weaned 4.8 per cent more calves than did the purebred cows, Table 16. However, these differences were not significant.
TABLE 16. REPRODUCTIVE PERFORMANCE OF PUREBRED AND CROSSBRED

Cows,

PHASE II

Purebreds Year
Cows

Crossbreds eng Pet. 90.9 76.7 81.0 87.8 58.7
68.5

WeaningsCowslW CosClig CalvesClig
Calving

No.

Pet.

Pet.

87.5 16 1961__________________________________ 62.5 1962 __________________________________ 69.2 26 80.8 39 66.7 1963__________________________________ 59.0 1964___________ ______ ___________ 46 69.6 65.2 1965________________ ________ 61 72.1 70.5 54 61.1 57.4 1966________ -----------1967__________________________________ 53 92.5 88.7 68.5 Total or average 295 74.2

No. 22 30 42 49 75
73

Pct. 90.9 73.3 78.6 81.6 58.7
64.4

------------

72
363

84.7
75.8

83.3
73.3

Reproductive performance was poor for Angus and Hereford cows in 1963, for Shorthorn cows in 1964, 1965, and 1966, and for the Hereford, Angus-Hereford, and Hereford-Shorthorn cows in 1965 and 1966. Trichomoniasis was diagnosed in one Angus and two Shorthorn bulls during 1965 and in one Angus and one Shorthorn bull in 1966. It is believed that this disease was introduced by a Shorthorn bull in 1963, and by the rotation of bulls was spread to other bulls and cow groups. Among the two-breed calves, the Hereford x Angus, Hereford x Shorthorn, and Shorthorn x Hereford were significantly (P<0.O1) heavier at birth
than were the other two-breed crosses, Table 17. The Hereford

x Angus and Hereford x Shorthorn calves were significantly (P<O.01) heavier at 250 days of age than any of the other twobreed crosses. In individual comparisons of the three-breed crosses, the A x (H x 5) and S x (H x A) calves were significantly (P<0.01) lighter at birth and at 250 days of age than were the other three-breed cross calves. Least-squares means and differences between two-breed and three-breed calves are shown in Table 18. In all comparisons, three-breed calves were significantly (P<0.01) heavier at birth, had a higher average daily gain, and were heavier at 250 days of age. All three-breed calves had a significantly (P<0.01) higher weaning score than did the two-breed calves. Three-breed calves from A x H cross dams had a significantly (P<0.01) higher weaning score than two-breed calves from purebred Angns and Hereford cows.

CROSSBREEDING

BRITISH

BEEF

BREEDS

17

CRSSBREEING~
TABLE 17.

BRITISH BEEF BREEDS

1

LEAST-SQUARES MEANS FOR PREWEANING PERFORMANCE, PHASE I'

Birth weight 250-day 250-day 250-day Weaning ADG WDA weight No. Lb. Lb. Lb. Lb. A x H------------------- 35 _----62.5bc 1.49b 1.74 434c 9.6bc A x S -------------------------------30 58.lbc 1.47b 1.70 424c 9.8abc 4 H x A-------------------------------42 67.5a 1.6 a 1.91 478ab 10.4a H x S---------------5_-------------35 68.lab 1.58a 1.86 464b 10.3ab S x A------------------------------- 29 60.7bc 1.50b 1.74 436c 9.9abc S xH H-------------_-------8------35 68.8a 1.43b 1.71 427c 9.3bc A x (H x S)-------_------------- 62.3bc 52 1.47b 1.72 430c 9.Qbc A x (S x H)------_------------45 67.2b 1.68a 1.95 488a lO.ab H x (A x S)------_------------48 67.7ab 1.66a 1.93 482ab 10.a H x (S x A)----------------------51 60.7a 1.67a 1.90 489a lO.ab S x (A x H)-------------------- 28 68.7a i.la 1.88 470ab 10.4a S x (H x A)--------------- 64.3bc _----42 1.49b 1.74 436c l0lab Breed of calf

Calves

score'

_---

'Means followed by different letters differ at P<0.01. 2Grade code: 9 - low Good; 10 = average Good; 11 high Good, etc.
TABLE 18. LEAST-SQUARES MEANS AND DIFFERENCES BETWEEN CALVES FROM CROSSBRED AND PUREBRED DAMS, PHASE II

Breed of

bull
S S H H A A

Birth
Breed weight

No. AxH&Hx A---------------70 ---------- 64 A and H-----------------

Difference-----------------

Lb. 66.5 64.8

250-day 250-day Weaning ADG weight score' Lb. Lb.
1.55 453 10.3

-

1.7*0

1.47
0.08

_---

_--

99 69.2 1.67 AxS&Sx A-----------------67.8 1.61 77 A and S---_-----------------------0.06* -1.40* Difference----------------97 1.58 HxS&Sx H----------------65 60.3 1.48 H and S---------------------------4.50* 0.100 Difference--------------66.8 1.60 Crossbred dams--------- 266 Purebred dams--------206 64.3 1.52

432 21* 486
471

9.6
0.7*

10.4
10.4

64.8

15
459
429

0.0
9.7
0.3

10.0

--

Difference-------------.

--

2.5*0

3 0 466 444

0.080#

22* 0

10.2 9.9

0.3*0

' Grade code: 9

-

low Good; 10

average Good; 11 = high Good, etc.

Post-weaning performance results of heifers are listed by breeding groups in Table 19. There were no significant differences in average daily gain dur-ing the pasture period. The significant differences in final pasture weights are due to the differences that existed in actual weaning weight and the slight differences in average daily gain. During the feedlot period, the Hereford x Shorthorn and Shorthorn x

did the S x (H x A). There were no significant differences in average daily gain for other individual comparisons. Because of small differences in average age of the heifers at the completion

Hereford heifers gained significantly

(P<O.O1) faster than

18

18 ALABAMA AGRICULTURAL EXPERIMENT STATION
LEAST-SQUARES MEANS FOR POSTWEANING PERFORMANCE OF HEIFERS PHASE IFl Pasture period

TABLE 19.

Feedlot period FinalWDa
egtAD D coe g

Breed of Heif- Weanheifer ers
ing

Period

weight

2

Final weight
wegtADG

Ax H______. AxS .______ HxA.______ Hx S______ SxA------SxH.______ Ax(HxS)__. Ax(SxH)__. Hx(AxS)__. Hx(SxA)__. Sx(AxH)__. Sx(HxA)__.
1

No. 24 18 23 17 15 16 23 24 23 24 13 16

417 407 452 432 399 406 405 458 465 463 447 395

67 68 81 64 77 84 82 74 63 81 76 75

464bc 444c 501ab 468bc 464bc 481abc 455c 504ab 498ab 519a 497ab 444c

0.70 0.55 0.61 0.56 0.83 0.89 0.62 0.64 0.53 0.70 0.65 0.74

Lb. 671bc 629c 704ab 682ab 659bc 693ab 656bc 707ab 704ab 729a 703ab 623c

Lb. 1.69ab 1.51ab 1.66ab 1.75a
4 1.7a 1.64ab 1.66ab 1.68ab 1.72ab 1.69ab 1.46b

Lb. 1.54abc 1.44bc 1.56a 1.58a 1.52ab 1.45bc 1.61a 1.63a 1.62a 1.5a 1.40b

12.2ab 12.lab 12.5a 12.8a
12.5a

Days 436 437 451 432
448

1.6lab 1.47bc

11.8b 12.lab 12.3ab 12.7a 12.7a 12.8a 11.b

456 452 439 432 450 445 445

2

Means followed by different letters differ at P<0.05. Unadjusted weaning weight. 'Grade Code: 11 - high Good; 12 - low Choice.

of the feedlot period, weight per day of age is the best estimate of total growth. The weights per day of age of Angus x Shorthorn, Shorthorn x Angus, A x (H x S), and S x (H x A) were similar to the Angus x Hereford and Shorthorn x Hereford, but were significantly (P<0.01) lower than any other group. The significant differences in final feedlot weights were due to cumulative effect of differences in initial feedlot weight and the

ferences

dif-

inaverage daily gain.

There were small but significant

(P<0.01) differences among breeding groups for conformation scores at the end of the feedlot period. However, there was no specific pattern and. the difference from high to low amounted to only one-third of a grade. Post-weaning means and. their differences for two-breed and three-breed cross heifers are shown in Table 20. The two-breed heifers sired by Shorthorn bulls gained faster on pasture than the three-breed heifers by Shorthorn bulls. This difference was large enough to result in almost equal weights at the end of the pasture period. Although the three-breed cross heifers gained faster on the average than the two-breed cross heifers during the pasture period, the difference was not significant. The average final pasture weight of all three-breed heifers was significantly (P<0.01) heavier than the final weight of the two-breed heifers.

CROSSBREEDING

BRITISH

BEEF

BREEDS

19

TABLE 20.

LEAST-SQUARES

MEANS AND DIFFERENCES IN POSTWEANING
FOR CROSSBRED AND PUREBRED DAMS,

PERFORMANCE OF HEIFERS

PHASE II

Breed
rof bull

Pasture period

Feedlot period

S S H H A A

1 FinalFinal Final naScor nalt ADG ght ADG ing weightei weight WDA No. Lb. Lb. Lb. Lb. Lb. Lb. Ax H & H xA._____ 29 421 471 .70 663 1.65 1.49 12.2 A and H............... 31 403 472 .86 676 1.68 1.49 12.2 Difference 18 -1 -0.16 -13 -0.03 0.00 00.0 AxS &Sx A-..... 47 464 509 0.62 716 1.70 1.63 12.7 A and S.___________ 40 442 485 0.59 693 1.71 1.57 12.7 Difference 22 24** 0.03 23* -0.01 .06 00.0 HxS&SxH...... 47 432 479 0.63 682 1.65 1.53 12.2 H and S____________ 42 412 454 0.56 650 1.60 1.49 12.2 Difference .-......... 20 25** 0.07 32** 0.05 0.04 00.0 Crossbred dams.. 123 439 486 0.63 687 1.64 1.55 12.3 Purebred dams 113 418 470 0.69 673 1.66 1.52 12.3 Difference ____ 21 16* -0.06 14**0.02 0.03 00.0

Breed of
cows

Heif- Wea Weaners

-...

1Grade
**

* P<0.05.
P<0.01.

code: 9 = low Good; 10 = average Good; 11 = high Good, etc.

Differences in average daily gain, weight per day of age, and conformation score at the conclusion of the feedlot period were not significant. The three-breed heifers sired by Angus bulls were significantly (P<0.05) heavier than the two-breed heifers sired by Angus bulls. The significant difference in final feedlot weights between three-breed and two-breed crosses was primarily due to the difference in weaning weights. Post-weaning performance by breed of steer is shown in Table 21. The Hereford x Shorthorn and Shorthorn x Hereford steers had the highest average daily gain (1.86 pounds) of any group. The Shorthorn x Angus and Angus x Shorthorn had the lowest daily gain, 1.59 and 1.60 pounds, respectively. The Hereford x Angus, Hereford x Shorthorn, and H x (S x A) made the most rapid gain throughout the entire experiment and thereby reached 1,000 pounds at average ages of 527, 527, and 530 days, respectively. Due to their slow growth rate in the feedlot, the Angus x Shorthorn, Angus x Hereford, Shorthorn x Angus, and A x (H x S) steers had lower weights per day of age than other breed groups. There were small but significant (P<0.05) differences among conformation scores. Least-squares means for post-weaning performance for twobreed and three-breed steers are shown in Table 22. When all three-breed steers were compared with all two-breed steers, there

20

ALABAMA

AGRICULTURAL

EXPERIMENT

STATION

20
TABLE 21.

ALABAMA

4GRICULTURLEPRMN

TTO

LEAST-SQUARES MEANS FOE POSTWEANING PERFORMANCE OF STEERS,

PHASE II

Breed of steers

Steers Weaning Final weight 2 weight Lb. No. Lb.

ADG Lb.

WDA Lb. 1.71b 1.68b 1.88a 1.88a
1.69b 1.77ab

Score3

Age Days 578b 590b 527a 5 27a
590b 563ab

989 11 A x H________________-___- 436 991 449 11 A x S_____________________ 483 991 19 H x A____________________ 476 991 16 H x S____________________ 14 458 S x A---------------------- 998 997 415 _-------- 19 S x H----------991 29 A x (H x S)____________ 439 997 498 21 A x (S x H) 994 481 25 H x (A x 1,002 503 H x (S x A)___________ 27 999 477 S x (A x H)__________ 15 993 466 25 S x (H x A)

1.7Oab
1.6Gb 1.84a 1.86a 1.59b 1.86a 1.65b 1.7lab 1.66b 1.79a 1.68ab 1.69ab

14.Oab 14.2a 13.9ab 13.hb
14.8a 13.5b

------S)----------------------

1.69b
1.83ab 1.77ab

14.3a
13.3b 14.2a

586b
545ab
562ah

1.89a 1.78ab
1.76ab

13.7b 14.5a
14.7a

530a 561ab
564ab

1 Means followed by different letters differ at P<0.05. 2

'Grade
Breed bull S S H H A A
-__ -__

Unadjusted weaning weight. code: 13 = average Choice; 14 = high Choice, etc.
TABLE 22. LEAST-SQUARES MEANS AND DIFFERENCES IN POSTWEANING PERFORMANCE OF STEERS FROM CROSSBRED AND PUREBRED DAMS,

PHASE II

Bf

AG gFnl Steers Weaning Final 1 weight weightA cow Lb. Lb. Lb. No. 1.69 996 471 AxH& Hx A_____. 40 1.73 998 33 437 A andH -0.04 3400 -2 Difference___________ ____ 1.73 998 492 52 AxS&SxA _______ 1.85 991 479 A and S----------- 35 13 70 -0.120 Difference____________ ____ 1.68 994 489 H xS & S xH____ 50 990 1.65 442 H and S________ 22 0.03 470~ 4 Difference------__ 996 1.70 477 Crossbred dams_. 142
Breed of

Bedo

WA Lb. 1.77 1.73
.04

Soe

g Days

14.6 14.2
0.4

562
576
-14

1.83
1.88

14.0
13.8

546
527

Purebred

Difference -----code: 13
=

dams---

-0.05 1.75 1.70 0.05 1.79
1.77
0.02

0.2 13.8 14.1 -0.3 14.1
14.0
0.1

19 565 584 -19 558
563
-5

90

453
24°0

993
3

1.74
-. 04

Unadjusted weaning weight.
2Grade

average Choice; 14= high Choice, etc.

*Significant
"*"

at P<0.05.

Significant at

P<0.01.

were no significant differences in average daily gain, weight per day of age, conformation score, or age at slaughter. However, the two-breed steers sired by Hereford bulls gained significantly faster (P<O.05) than did the three-breed steers sired by Hereford bulls. Means of steer post-weaning performance traits by sires are Hereford bulls had a higher shown in Table 23. Steers sired

by

CROSSBREEDING

BRITISH

BEEF

BREEDS

21

CROSSBREEDIN~G

BRITISH

BEEF BREEDS

2

average daily gain and weight per day of age than did steers sired by either Angus or Shorthorn bulls. Because of their heavier weaning weights and more rapid post-weaning gains, steers by Hereford bulls were younger than steers by Angus (39 and Shorthorn (34 days) bulls at the slaughter weight of 1,000 pounds. The dressing percentage for Angus x Shorthorn steers (63.3) was significantly (P<0.05) higher than Angus x Hereford (61.3), H x (S x A) (61.4), and Shorthorn x Hereford (61.5), Table 24. Other differences were not significant. Carcass weight per day of age was significantly (P<0.05) greater for the H x A, H x 5, and H x (S x A) steers than for the A x H, A x 5, S x A, and A x (H x 5) steers. Other differences were not significant.

days)

TABLE 23.

LEAST-SQUARES MEANS FOR POSTWEANING PERFORMANCE OF STEERS BY SIRES, PHASE II'

Breed of Sire

Hereford___________ Shorthorn -------1

Angus -------------2Unadjusted weaning weight.

Calves Weaning Final weight' weight No. Lb. Lb. 72 456 992 87 486 995 73 454 996

ADG Lb. 1.66 1.79 1.71

WDA Lb.
1.73

Score'
13.9

Age Days
575

1.86
1.75

13.9
14.3

536
570

Means followed by different letters differ at P<0.05.

' Grade code: 13 = average Choice; 14 = high Choice, etc.
TABLE 24. LEAST-SQUARES MEANS OF STEER CARCASS CHARACTERISTICS, PHASE

IF

Breed of Ser Carcass ster teers weight No. 11 11 19
16

A xiHl_________ Ax S__________ H x A___________
H x
S-----------

Lb. 606 627 614
613

Dressing per cent Pct. 61.3b 63.3a 6'1.9ab
61.9ab

Carc WD

FtTenthick- Ribeye thc-ns area nssscore Lb. In. Sq. In. 1.05b 0.79 10.6ab 1.06b 0.85 10.3ab 1.16a 0.73 11.Oa
1.16a 0.75

Quality Yield dergrade' grade' ness 4 13.9ab 14.2a 13.9ab
13GOb

S x A____________ 14 625 62.6ab 1.06b 0.87 lO.5ab 15.0a S x H____________ 19 613 61.5b 1.O8ab 0.76 9.9b 13.7ab A x (H x 5)______ 29 618 62.4ab 1.06b 0.76 10.7a 14.3a A x (S x H)_____,-_ 21 621 62.3ab 1.l4ab 0.79 lO.5ab 13.lb H x (A x 5)__--- 25 617 62.Oab i.llab 0.78 10.6ab 14.Oab H x(S xA)______ 27 615 61.4h 1.16a 0.68 10.9a 13.4b S x (A x H)_________ 15 618 62.2ab il1Oab 0.83 b0Ob 14.4a S x(H xA)______ 25 616 62.lab 1.O9ab 0.88 lO.5ab 14.7a ' Means followed by different letters differ at ' Grade code: 13= average Choice; 14 = high Choice, etc. ' The lower the yield grade the better the carcass. 4Warner-Bratzler shear values-lower values more tender.

10. lb

4.3 4.8 4.0
4.3

19.0 19.1 17.4
17.2

4.8 4.4 4.4 4.6
4.3

18.3 16.6 16.5 17.4
17.8

P<0.05.

3.9 4.6 4.7

18.9 16.0 16.7

22

ALABAMA AGRICULTURAL EXPERIMENT

STATION

The ribeye area of carcasses from Hereford x Angus, H x (S x A), and A x (H x S) were significantly larger (P<0.05) than the ribeye area from Shorthorn x Hereford, S x (A x H), and Hereford x Shorthorn. Other differences were not significant. There were small but significant (P<0.05) differences in carcass quality grades. Shorthorn x Angus had the highest grading carcasses (15.0) and Hereford x Shorthorn the lowest (13.0). There were no significant differences in fat thickness, steak tenderness scores, or yield grades. When all carcasses from two-breed and three-breed steers were compared, no significant differences were found in any of the traits measured, Table 25.
TABLE 25. LEAST-SQUARES MEANS AND DIFFERENCES IN CARCASS CHARACTERISTICS OF STEERS FROM CROSSBRED AND PUREBRED DAMS, PHASE II

Dress-TenBreedam dam Steers weight No. Lb. per
cent

CarCass CarCasres- r SteersCarcassin WDA Lb. Pct.

Fat athickes
ness

Ribeye rea
area

grade

Yield Qual- grade2 ity gre

derness
score

In.

Sq. In. 16.4 16.6 -0.2 16.9 19.0 -2.1 18.4 17.8 0.6 17.2 17.9 -0.7

4.7 14.6 10.3 0.86 1.10 62.2 617 A x H & H x A-.. 40 4.6 14.4 10.2 0.82 62.1 1.07 619 33 A and H_....... 0.2 0.1 0.1 .04 .03 0.1 -2 Difference 4.5 18.7 0.78 10.6 62.4 1.10 620 52 H x S & S x H 4.5 14.0 0.82 10.5 62.8 1.06 617 35 H and S 0.0 0.1 -0.1 .04 -. 04 3 0.1 Difference ........ 4.1 10.7 18.7 0.73 61.7 1.14 616 A x S & S x A_... 50 4.5 10.6 14.0 61.9 1.16 0.74 22 614 A and S 0.1 -0.3 -0.4 2 -0.2 -. 02 -. 01 Difference 4.4 10.5 14.0 62.1 1.11 0.79 617 Crossbred dams .142 10.3 14.0 4.4 616 62.1 1.10 0.79 Purebred dams--90 0.0 0.0 .00 0.2 1 0.0 .01 _ Difference 1 Grade code: 13 -= average Choice; 14 -= high Choice, etc. 2 The lower the yield grade the better the carcass. SWamrner-Bratzler shear values-lower values more tender.

CROSSBREEDING

BRITISH

BEEF

BREEDS

23

SUMMARY Angus, Hereford, and Shorthorn beef cattle were used in a cross-breeding program from 1957 through 1967. The following results were obtained: (1) There were no significant differences in the percentage of calves dropped or weaned by purebred cows producing purebred calves and those producing crossbred calves. (2) There were no significant differences between reproductive performance of purebred cows producing crossbred calves and two-breed cows producing three-breed calves. (3) Purebred Angus cows gave birth to and weaned a higher percentage of calves than either the purebred Hereford or Shorthorn cows. (4) Angus-Shorthorn cows dropped and weaned a higher percentage of calves than either the Hereford-Shorthorn or the Angus-Hereford cows. Hereford-Shorthorn cows dropped and weaned a higher percentage of calves than did the Angus-Hereford cows. (5) Two-breed calves gained more rapidly from birth to weaning, were heavier at 250 days of age, and had higher weaning scores than purebred calves. (6) Three-breed calves were heavier at birth, gained more rapidly from birth to weaning, were heavier at 250 days of age, and had higher scores at weaning than did the two-breed calves. (7) Purebred Angus cows produced calves that were lighter at birth but grew more rapidly from birth to weaning, weighed more at 250 days of age, and graded higher at weaning than the calves from either Hereford or Shorthorn cows. (8) Hereford bulls sired calves which were heavier at birth, gained more rapidly during pre-weaning and post-weaning, and had higher weaning scores than calves sired by either Angus or Shorthorn bulls. (9) Two-breed heifers had a higher post-weaning average daily gain while on pasture and a higher final weight per day of age than purebred heifers. (10) Differences between post-weaning average daily gain of two-breed and three-breed heifers were not significant. However, because they were heavier at weaning, the three-breed heifers had heavier final weights.

24

ALABAMA AGRICULTURAL

EXPERIMENT STATION

(11) Two-breed steers gained faster during the post-weaning pasture periods and had a heavier slaughter weight and a higher final weight per day of age than the purebred steers. (12) Differences between the post-weaning performance traits of two-breed and three-breed steers were not significant. (13) Two-breed steers produced heavier carcasses and had a higher carcass weight per day of age than purebred steers. Differences in other carcass traits were small and non-significant. (14) The differences between carcass traits of two-breed and three-breed steers were not significant.

CROSSBREEDING

BRITISH

BEEF

BREEDS

25

LITERATURE CITED

(1)
(2)

BUTLER, O. D., B. L. WARRICK, AND T. C. CARTWRIGHT. 1956. Slaugh-

ter and Carcass Characteristics of Shortfed Yearling Hereford and Brahman x Hereford Steers. J. Ani. Sci. 15:93. x Hereford Crossbreds - Gains, Carcass Yields and Carcass Differences. J. Ani. Sci. 14:218. (3) CLYBURN, T. M., W. C. MCCORMICK, R. L. SAFFLE, AND B. L. SOUTHWELL. 1961. Effects of Breed and Cross on Growth Rate and Carcass Characteristics of Beef Steers. J. Ani. Sci. 20:392 (Abstract). (4) DAMON, R. A., JR., S. E. MCCRAINE, R. M. CROWN, AND C. B. SINGLETARY. 1959. Performance of Crossbred Beef Cattle in The Gulf Coast Region. J. Ani. Sci. 18:437. (5) DAMON, R. A., JR., R. M. CROWN, C. B. SINGLETARY, AND S. E. McCraine. 1960. Carcass Characteristics of Purebred and Crossbred Beef Steers in the Gulf Coast Region. J. Ani. Sci. 19:820. (6) GAINES, J. A., W. H. McCLURE, D. W. VOGT, R. C. CARTER, AND
C. M. KINCAID. 1966. Heterosis from Crosses Among British Breeds of Beef Cattle: Fertility and Calf Performance to Weaning. J. Ani.
CARROLL, F.

D., W.

C.

ROLLINS, AND N.

R. ITTNER.

1955.

Brahman

Sci. 25:5.

(7)
(8)

J. A., G. V. RICHARDSON, W. H. MCCLURE, D. W. VOCT, AND R. C. CARTER. 1967. Heterosis from Crosses Among British Breeds of Cattle: Carcass Characteristics. J. Ani. Sci. 26:1217.
GAINES, GERLAUGH, PAUL, L.

E. KUNKLE, AND D.

C. RIFE.

1951. Crossbreed-

ing Beef Cattle. Ohio Agr. Exp. Sta. Res. Bull. 703.

(9)
(10)

GODLEY, W. C., E. G. GODBEY, E. D. KYZER, AND R. F. WHEELER.

1960. Crossbred and Purebred Dams for Production of Slaughter Calves. J. Ani. Sci. 19:203.
GREGORY, K. E., L. A. SWIGER, R. M. KOCH, L. J. SUMPTION, W. W. ROWDEN, AND J. E. INGALLS. 1965. Heterosis in Preweaning Traits

of Beef Cattle.

J. Ani. Sci. 24:21.
J.
SUMPTION, AND

(11)

J. E. ROTHILISBERGER. 1966. Heterosis Effects on Growth Rate of Beef Heifers. J. Ani. Sci. 25:290. (12) GREGORY, K. E., L. A. SWIGER, L. J. SUMPTION, R. M. KOCH, J. E.
J. A. ROTHLISBERGER. 1966. Heterosis Effects on Growth Rate and Feed Efficiency of Beef Steers. J. Ani. Sci. 25:299. (13) GREGORY, K. E., L. A. SWIGER, L. J. SUMPTION, R. M. KocH, J. E.
INGALLS, W. W. ROWDEN, AND
INGALLS, W.

GREGORY, K. E., L. A. SWIGER, R. M. KOCH, L.

W. ROWDEN, AND J. A. ROTHLISBERGER. 1966. Heterosis Effects on Carcass Traits of Beef Steers. J. Ani. Sci. 25:311.

(14)

HARVEY,

WALTER

R.

1960. Least-Squares Analyses of Data with

Unequal Subclass Numbers. USDA, ARS. 20-8. (15) KINCAID, C. M. 1962. Breed Crosses with Beef Cattle in the South.

Texas Agr. Exp. Sta. Southern Coop. Series Bull. 81.

(16)

KNAPP, BRADFORD, JR., A. L. BAKER, AND R. T. CLARK.

1949. Cross-

bred Beef Cattle for the Northern Great Plains. USDA Cir. 810.

26

ALABAMA AGRICULTURAL EXPERIMENT

STATION

(17) KRAMER, C. Y. 1957. Extension of Multiple Range to Group Correlated Adjusted Means. Biom. 13:13. (18)
PAHNISH, O.
RILEY.

F.,

J.

S. BRINKS,

J. J.

URICK, W.

B. KNAPP, AND T. M.

1969. Results from Crossing Beef x Beef and Beef x Dairy Breeds: Calf Performance to Weaning. J. Ani. Sci. 28:291.

(19)
(20)

PHILLIPS, RALPH W., W.

H.

BLACK,

B.

KNAPP, JR., AND R. T.

CLARK.

1942. Crossbreeding for Beef Production.
ROLLINGS, W. C., R. G.

J. Ani. Sci. 1:23.
AND K. A. WAGNON.

Loy,

F.

D.

CARROLL,

1969. Heterotic Effects in Reproduction and Growth to Weaning in Crosses of the Angus, Hereford and Shorthorn Breeds. J. Ani. Sci. 28:431.

(21)
(22)

STEELE, ROBERT G.

D.

AND JAMES

H. TORRIE.

1960.

Principles and

Procedures of Statistics. McGraw-Hill Book Co., New York, N.Y.
TEMPLE,

R. S. AND D.

D.

MILLER.

1961. A Comparison of Calving

Percentages and Preweaning Performance of Various Breeds of Beef Cattle in a Crossbreeding Program. J. Ani. Sci. 20:392 (Abstract). (23) TURNER, J. W., B. R. FATHERING, AND G. L. ROBERTSON. 1968. Heterosis in Reproductive Performance of Beef Cows. J. Ani. Sci. 27:336. (24) TURNER, J. W. AND R. P. MCDONALD. 1969. Mating-Type Comparisons Among Crossbred Beef Cattle for Preweaning Traits. J. Ani. Sci. 29:389.

(25)

MCCLURE, AND VOGT, D. W., J. A. GAINES, R. C. CARTER, W. H. C. M. KINCAID. 1967. Heterosis from Crosses Among British Breeds of Beef Cattle. Postweaning Performance to Slaughter. J. Ani. Sci.

26:443.

(26)

WILTBANK, J. N., K. E. GREGORY, J. A. ROTHLISBERGER, J. E. INGALLS, AND C. W. KASSON. 1967. Fertility in Beef Cows Breed to Produce Straightbred and Crossbred Calves. J. Ani. Sci. 26:1005.

CROSSBREEDING

BRITISH

BEEF

BREEDS

27

APPENDIX The mathematical model used for analysis is as follows:
Xijklnn
-

a + Yi + Aj + Bk + S1 +YB(ik) + YS (ii) + BS (k) + W/BY(mki) + b 1 (BD) - b 2 (BD) 2 + b3 (BD) 3 + Eijklmn.

Where: a = the overall mean for the Xijklm when equal frequencies exist in each of the subclasses and birth date equals 0. Yi = the effect of the i-th year. Aj = the effect of the j-th age of dam. Bk = the effect of the k-th breed of calf. S1 = the effect of the 1-th sex of calf. YB(1k) = the effect of the interaction of the i-th year and the k-th breed of calf. YS (ii) = the effect of the interaction of the i-th year and the 1-th sex of calf. BS(k1) = the effect of the interaction of the k-th breed of calf and the 1-st sex of calf. W/BY(mki) = the effect of the m-th sire within the k-th breed of calf and the i-th year subclass. bl = partial regression of the dependent variable (X) on the linear form of BD. b2 = partial regression of the dependent variable (X) on the quadratic form of BD. b3 = partial regression of the dependent variable (X) on the cubic form of BD. BD = date of birth of calf.
Eijklmn-- the random error.

Because of computer capacity limitations, the breed of sire and breed of dam effects were analyzed using the following linear model: a +j k A + Sm + YM (ij) +YF (ik) Xijklmn
YS(im) +

b2(BD)

2

MF(jkl) + MS(±) + + b 3 (BD) 3 + Eijklmn.

FS(km) -

b1(BD) +

The components of this equation are defined as in the previous equations with the following additions: M = the effect of the j-th breed of sire. F = the effect of the k-th breed of dam. Various linear functions of these subgroup least-squares means were used to determine heterotic effects of specific crosses. Standard errors of the linear functions of these means were calculated, as described by Gregory et al. (10) from the least-squares variance - covariance matrix for these subgroup means and from the error mean square for each trait from the analyses of variance. A least-squares analysis of weight changes and conformation sources from weaning through both post-weaning periods was made for both heifers and steers. As a result of length of calving season and method of management during Phase I,the number of days calves were in the postweaning pasture period depended on date of birth. Because of this varia-

28

28 ALABAMA AGRICULTURAL EXPERIMENT STATION

lion, number of days during the pasture period and initial age of calf at beginning of feedlot period were included as dependent variables in the
post-weaning analysis. The following model was used for post-weaning B;± YB (1J) ± W/BY (mji) +
E1 j 1 l.

performance analysis :
Xi~kl

-a
=

+ Yi+

Where
Ejikl

YB (ii)=

W/BY(rnji)_
A ti

the effect of the i-th year. the effect of the j-th breed of calf. the effect of the interaction of the i-th year and the j-th breed of calf. the effect of the m-th sire within the k-th breed of calf and the i-th year subclass. the random error.

The results of the analyses are summarized in Appendix Tables 1 through 10.

APPENDIX

TABLE 1. LEAST-SQUARES CONSTANTS FOR AGE OF DAM CALF AND REGRESSIONS ON DATE OF BIRTH, PHASE

I

AND

SEX OF

Effect
Age

Birth weight

250-Day weight -14.92
-

Daily gain, Birth-250 days -0.158 -0.045

of dam'
34 -8.0147.63
-------------------

-3.58
0.17 -0.83

5-----------------6------------------

4.25
2.15

7 ----------------8------------------

1.33

13.80
1.72

0.14

9-----------------10-----------------_-

-0.73
2.46

8.13
28.04

-0.018 -0.008 0.049 -0.008 0.034
0.102

11 -& older---------Sex of calf

8.55
-1.03 1.03

21.18
-13.64 13.64

0.051 -0.0,50
0.050

Heifer -------Regression on
date

_-----

Steer ---------------of birth
Linear-------------Quadratic-------------------------

Cubic Average--------------1

0.00086593 -0.00016739
0.00000881 65.39

0.03285865 0.00942919
454.63

0.00012377 0.00003829
-0.00000025 1.557

Age of dam expressed in years.

CROSSBREED'ING

BRITISH

BEEF

BREEDS

29

CROSSBREEDING

BRITISH

BEEF BRFEEDS
MEAN SQUARES OF PREWEANING TRAITS, PHASE

2 I

APPENDIX TABLE 2.

Source of
variation

d.f.

Birth
weight

250-day
ADG
0

250-day weight
4

Weaning score
26.84*

Year --------------------------4 232* 0.1520 10863 Age of dam8 35* 0.047 41872.73 Breed_ 8 433n" 0.1301" 9427"'

--1

Sex_______________

Year x breed_______
Year x

sex ---------

32
4

1474 66
83

0.35600 0.021
0.022

3.960
0.02

25957*4*

1521.
1121

3.85:00
0.92 0.83

1.62

Breed x sex-------x breed)--

Sire/(year
Linear

8 43

39 83*

0.041 0.015

2995 1247

Regression on

date of birth
Quadratic

Cubic_____Error_____ _*P<0.05.

140

1 1 1

0 1 52 54

0.001 0.0690 0.043 0.030

74 4235 2010 2145

1.82 1.46 1.45

P< P0O.01.

APPENDIX TABLE

3.

MEAN SQUARES FOR HEIFER POSTWEANING PERIODS FROM LEAST-SQUARES ANALYSES, PHASE I

Source of variation Breed____________________
Year_________________

d.f. 8
4
22

Initial age 548
3958**

Days on pasture 600 954
1287

3937**
905

Days in feedlot 0

Breed x year___________________ 27

Sire/(breed

969
1319

397**4
0
0

48304*0

Final age 459

1185
1319

x year)------

Error_________________________ 04 P<0.01.

56

882

0

883

APPENDIX TABLE

4.

MEAN SQUARES FOR STEER POSTWEANING LEAST-SQUARES ANALYSES, PHASE I

PERIODS FROM

Source of variation

d.f.

Breed --- ------ ----- ---- --8 Year--- -- --- - ----------4
Breed x year-30

Initial age 1039
r-o

Days on pasture 1087
r

Days in feedlot 167
1521404

Final age 1640
c

6278**

6069"*

3439*4

E rror-----------------*P<0.05.

Sire/(breed x
**

year)-------30

49

912 12210 694

911 1239* 655

95 69 145

941 1384* 790

P<0.01.

30

30 ALABAMA AGRICULTURAL EXPERIMENT STATION
APPENDIX TABLE 5. MEAN SQUARES FOR CARCASS CHARACTERISTICS, PHASE

I

Dressing per cent Breed _-------------- 8 3.425 Year-- _ ---------- 3.587 -------4 Year x breed 30 1.050 Sire/(year x breed)-___ 30 1.347

Source of variation

d.f.

Carcass Fat Ribeye WDA thickness area 0.033*° 0.93** 0.009 0.007
0.007

Quality grade
6.051**

Shear value
17.854
23.054

-------

----------2.043

Error__________________________ 48 * P<0.01.
**

0.176** 1.370 0.725** 13.393* 0.667*0 1.778 0.018 1.278 0.013 1.245

6.26100
1.607

11.777

0.847

1.347

14.418

21.948

P<0.05.

APPENDIX TABLE 6. LEAST-SQUARES CONSTANTS FOR AGE OF DAM AND SEX OF CALF AND REGRESSIONS ON DATE OF BIRTH, PHASE II

Effect Age of dam' 3-------

Birth weight
-4.59

250-day weight
-30.72
-

Daily gain, birth-250 days
-0.105

4---------

5----------------------------------6---------------------------------7---------------------------------8----------------------------------9--------------------------

-0.43

9.17

0.17 2.57 0.85 1.27
0.26
-

10-------------------------------- 2.64 0.011 Sex of calf Heifer----------------------------1.80 -16.15 Steer ------------------------------1.80 16.15 0.058 Regression on date of birth Linear ------0.01689012 0.66272819 0.00274906 Quadratic ------------------0.00121071 -0.00591787 -0.00002929 Cubic-------------------------0.00000849 0.00002720 0.00000015 Average ------- -----------65.55 454.88 1.558 1Age of dam expressed in years.

-0.11

8.61 10.00 11.69 10.90 3.98

-0.035

0.034 0.029 0.043 0.040 -0.017

-0.058

--------------------

-----

APPENDIX TABLE

7.

MEAN SQUARES OF PREWEANING TRAITS, PHASE

II

Source of variation

d.f.
6 7 11 1 6

Birth weight

250-day ADG

250-day weight

Weaning score

Year------------___--Age of dam----

Breed ----------------Sex------------------Year x sex___----------

----___

221"
512*4 1169" * 51

49

0.12400
0.338" 1.1950 0.014

0.1360

0

#

797604 1018500 260960* 9393700
864

42.3200
4.920~ 5.560* 0.33

Year x

breed -------

4.80*4
1.55
1.19

Breed x

sex------------

65
11

54
58

0.020
0.018

1350
1242

Sire/(year x

breed)

-_---

54

83
13 72 50 64

0.024

1847
19627**0 1722 508 1824

1.25

Regression on date of birth

Linear --------------

Cubic----------Error--------

Quadratic
*P<0.05.

--------

1 1 1 _------------307
.

0.338*
0.042 0.015 0.025

21.800'
7*77*

5.56*
1.34

140< P0.01.

CROSSBREEDING

BRITISH

BEEF

BREEDS

31

CROSSBREEDING BRITISH BEEF BREEDS
APPENDIX TABLE 8.

3

MEAN SQUARES FOR HEIFER POSTWEANING PERFORMANCE, PHASE II

Source of variation

d.f.

Days on Pasture pasture ADG

Feedlot ADG
0.092
2.354**

weight

Final

Breed_______________________ Year____---------Error________________
*

_--------_------

11 6

Breed x year ______________ 60 ____ Sire/(year x breed)---------41

853 2079000 627

0.449 1.465"
0.784

15136** 29184**0
2960
3713 3300

Final WDA
.078*
0.047*

0.057
0.054 0.048

0.019
0.021 0.019

486 0.743 ________________ 117 535 0.562

**

P<0.05. P<0.01.
MEAN SQUARES FOR STEER POSTWEANING PERFORMANCE, PHASE II

APPENDIX TABLE 9.

Source of variation

d.f.

Average daily gain

Final weight
225
391*

WDA

Final

Breed_______________________________ 11 0.118'* Year -------------------------------- 0.460* * 6
Breed x year_____________________ 56 0.055

0.083*4
0.030
0.030

Conformation score

Sire/(year x breed)----------Error________________________________ 0 P<0.05. ** P<0.01.

41 117

0.052 0.041

262** 32304
151

Q359** 0.027

10.53**
1.63
1.25

3.38*

1.34

APPENDIX TABLE 10. MEAN SQUARES FOR CARCASS CHARACTERISTICS, PHASE II

Source of variation

d.f. ing

Dress-

per cent

Carcass Fat Ribeye WDA thickness area
0.026* 0.054 1.703**

Quality Yield Shear grade grade' value'

Breed
Year

------------11
-

0.820

-_________

6 1.081

Year x breed-----'Yield

0.132*" 0.226* * 3.346* *

Sire/ Error____________
*P<0.05. **

56 0.570

0.011
0.010

0.077*
0.041

0.885
0.789

6.162** 0.99* 1.393
4.858** 1.02

12.3

2.9311 20.3

(year x breed)- 41 0.529

11.9
10.4

116 0.551 0.009 0.052 0.672 grade and shear values not obtained for 1961.

1.276

1.426

0.54

0.70

9.9

P<0.01.

AGRICULTURAL EXPERIMENT STATION SYSTEM OF ALABAMA'S LAND-GRANT UNIVERSITY

With ani agricultural
research unit in every

major soil area, Auburn
University serves the

needs of field crop, livestock, forestry, and horticultural producers in each region in Ala-

,

bama. Every citizen of
the State has a stake in this research program,
.

K

G Q

(D

since any advantage from new and more economical ways of
producing and handling f

-

r

-

7
i
J

T

farm poducts public.

directly

benefits the consuming

0

Research Unit Identification

*
1. 2. 3. 4. 5. 6. 7.

Main Agricultural Experiment Station, Auburn.

Tennessee Valley Substation, Belle Mina. Sand Mountain Substation, Crossville. North Alabama Horticulture Substation, Cullman Upper Coastal Plain Substation, Winfield. Forestry Unit, Fayette County. Thorsby Foundation Seed Stocks Farm, Thorsby. Chilton Area Horticulture Substation, Clanton. S. Forestry Unit, Coosa County. 9. Piedmont Substation, Camp Hill. 10. Plant Breeding Unit, Tallassee. 11. Forestry Unit, Autauga County.
12. Prattville Experiment Field, Prattville.

13. 14. 15. 16. 17. 18. 19. 20. 21.

Black Belt Substation, Marion junction. Tuskegee Experiment Field, Tuskegee. Lower Coastal Plain Substation, Camden. Forestry Unit, Barbour County. Monroeville Experiment Field, Monroeville. Wiregrass Substation, Headland. Brewton Experiment Field, Brewton. Ornamental Horticulture Field Station, Spring Hill. Gulf Coast Substation, Fairhope.