|
Bulletin 814 (technical)
Feedlot Performance and Carcass Traits
of Angus, Brahman, Charolais, and
Reciprocal F, Crosses of
The Three Breeds
F. M. Peacock, M. Koger, A. Z. Palmer, and
J. W. Carpenter
Agricultural Experiment Stations
institute of Food and Agricultural Sciences
University of Florida, Gainesville
F. A. Wood, Dean for Research
March 1980
Feedlot Performance and Carcass Traits of
Angus, Brahman, Charolais, and
Reciprocal Fi Crosses of the Three Breeds
F. M. Peacock, M. Koger, A. Z. Palmer, and
J. W. Carpenter
This public document was promulgated at an annual cost of
$990 or a cost of 33 cents per copy to provide information on
the effects of breed and heterosis on feedlot performance and
carcass traits of cattle.
AUTHORS
Mr. Peacock is a professor of animal husbandry at the Agricultural Re-
search Center, Ona. Dr. Koger is a professor of animal genetics and Drs.
Palmer and Carpenter are professors of meat science in the Animal Science
Department, Gainesville.
.UNIVERSITY OF FLORI-(
CONTENTS
Page
INTRODUCTION................. .............................. 1
EXPERIMENTAL PROCEDURE ................................. 1
RESULTS AND DISCUSSION ................................. 3
Growth Related Traits ........................................ 3
Slaughter Data ............................................. 3
Intransit shrink and dressing percentage ....................... 3
Ribeye area per 100 lb carcass weight .......................... 5
Fat over eye ................................................ 5
Kidney, pelvic, and heart fat percent ........................... 5
Estimated yield ........................................ 8
Qualitative Carcass Traits ....................................... 8
Maturity score .............................................. 8
Conformation score ......................................... 9
Marbling score ............................................ 9
Carcass quality grade ............................. ............ 9
Warner-Bratzler shear ...................................... 11
Tenderness score ................ .......................... 11
SUMMARY .....................................................12
LITERATURE CITED ...........................................13
INTRODUCTION
Crossbreeding for commercial production of beef has become
widespread in recent years. Information on the effects of breed and
heterosis on growth, feedlot performance, slaughter characteristics,
and carcass characteristics are more important than ever before in
designing effective beef production systems. The wide variation in
breed types of beef cattle available offers the opportunity for combin-
ing these resources with production requirements. Gregory et al. (1),
from Nebraska research, reported the effects of heterosis on carcass
traits of crosses among Angus, Hereford, and Shorthorn breeds. Data
on quantitative and qualitative carcass characteristics of crosses in-
volving the Angus, Hereford, and Charolais breeds from Missouri
have been reported by Hedrick et al. (4) and by Lasley et al. (7). Re-
sults from a large number of crossbred groups studied at the Meat An-
imal Research Center, Clay Center, Nebraska, have been presented
(Koch et al., 5; Koch and Dikeman, 6). However, published data in-
volving the Brahman breed are limited. The objective of this study
was to obtain information on the effects of breed and heterosis on
growth, slaughter traits, and carcass traits of Angus, Brahman, and
Charolais steers and the reciprocal Fi crosses of these breeds. The An-
gus, Brahman, and Charolais animals represent three distinct, ge-
netically divergent breed types that are of commercial importance in
the southern region of the United States.
EXPERIMENTAL PROCEDURE
The steers used in this study were produced over an 11-year period
during the first phase (1964 through 1974) of a crossbreeding project
designed to evaluate Angus, Brahman,and Charolais breeds and
their crosses. Bulls of each of the three breeds were mated to equal
numbers of cows of each breed in a 3 by 3 diallel design. The number
ofsteers produced in each of the nine mating groups is shown in Table
1. There were a total of 352 steers sired by 27 bulls, nine bulls of each
breed.
Matings occurred during a 90-day breeding season. Calves did not
receive supplemental feed prior to weaning, which occurred in the
latter part of September. After a post-weaning adjustment period,
the calves were fed a concentrate diet for an average of 176 days and
slaughtered as a group. The diet was composed of 17% cottonseed
meal, 51% dried citrus pulp, 26% cracked corn, 5% alfalfa, and 1%
mineral. In addition, the calves were fed 2.5 lb (1.14 kg) per head
daily of Pangola digitgrass hay (Digitaria decumbens).
The data utilized in evaluating the pre-slaughter performance of
steers included weight when placed on feed; standardized final
Table 1. Experimental design and number of steers by breeding groups.
Breed of Sire
Breed of Dam Angus Brahman Charolais Total
Angus 34 44 27 105
Brahman 33 43 48 124
Charolais 44 34 45 123
Total 111 121 120 352
weight determined from carcass weight, assuming a chilled dressed
yield of 60%; daily gain based on standardized final weight; and
dressing percent based on chilled carcass weight and preslaughter
weight taken at the plant.
The finished steers were slaughtered at the University of Florida
meats laboratory, Gainesville, where slaughter and carcass data
were collected. Cold carcass weights were obtained after chilling for
48 hours at 2 to 3C. Estimated percent yield was used as a measure
of boneless, closely trimmed major cuts from the round, rump, loin,
rib, and chuck. This variable was determined from estimated kidney
fat, fat over the longissimus muscle (ribeye), ribeye area, and hot car-
cass weight. Beef carcass quality grades were based on USDA grade
standards in effect prior to April 14, 1975. Carcass maturity values
were converted to scale for statistical analysis, with A- maturity be-
ing represented by 1, typical A maturity by 2, and A+ maturity by 3.
Carcass conformation and USDA quality grade scores were derived
as follows: average Choice 17; low Choice, 16; high Good, 15; etc. De-
gree of marbling scores were given numerical values as follows: aver-
age small, slight, and traces, 11, 8, and 5 respectively. Measurements
of the ribeye area and thickness of fat over the ribeye were made be-
tween the 12th and 13th ribs.
Shortloin samples were removed from carcasses after a 48-hr chill,
wrapped, and frozen at 180C. Steaks were cut approximately 2.5 cm
thick and defrosted 48 hours at between 0 and 20C before broiling.
Steaks were cooked to a medium degree of doneness by broiling 9 min
on the first side and 8 min on the second side at a distance of approxi-
mately 10.2 cm from the heating element; this procedure provided
steaks cooked to an approximate internal temperature of 700C, al-
though final internal temperature of individual steaks was not moni-
tored. From each carcass one steak was broiled for taste panel evalua-
tion and another steak was broiled for Warner-Bratzler shear deter-
minations.
For the taste panel evaluation, the broiled steaks were cooled at
room temperature for at least 30 min. The longissimus muscle of each
steak was then cut into four sections and served to an experienced
four-member taste panel. Tenderness was evaluated on a scale vary-
ing from 1 (extremely tough) to 9 (extremely tender) with 5 designat-
ing average tenderness. Steaks broiled for Warner-Bratzler shear
measurements were cooled similarly, and three 1.27-cm cores were
removed parallel to the direction of the muscle fiber. Each core was
sheared twice, resulting in six shear readings per steak.
Data were analyzed by least squares procedures to obtain breed
subclass means (Harvey, 2). Variables included in the model were
breed of sire, breed of dam, breed of sire x breed of dam interaction,
year, and age of steer (Table 2). The experimental design and number
of observations by breeding groups are presented in Table 1.
RESULTS AND DISCUSSION
Analyses of variance for the traits measured are shown in Table 2.
The least squares means and direct heterosis estimates for traits
measured are presented in Tables 3 and 4.
Growth Related Traits
Weights taken on cattle directly from the feedlotmay reflect signif-
icant biases due to differences in fill. Carcass weights and standard-
ized final feedlot weights, assuming a chilled dressing yield of 60%,
were used in evaluating the principal growth responses realized in
this study. The growth related traits measured were initial feedlot
weights, daily gain in the feedlot, final weight, and chilled carcass
weight.
Average breed effects on initial weight, final weight and carcass
weight were similar with both breed of sire and breed of dam effects
ranking in ascending order for the Angus, Brahman, and Charolais
breeds. The effects of heterosis for weight in reciprocal crossbred
progeny were highest for the Angus-Brahman crosses and lowest for
the Angus-Charolais crosses. The net effect of these heterosis influ-
ences are reflected in carcass weights. Heterosis effects in carcass
weights were 5.5% for Angus-Charolais reciprocals, 9.4% for the
Brahman-Charolais and 18.4% for Angus-Brahman crosses. These
results are in general agreement with other studies involving these
breeds and their crosses (Lasley et al. 7).
Slaughter Data
Intransit shrink and dressing percentage. Intransit shrink (live
animal weight loss) was determined for the 185-mile, 5-hr haul from
the ARC, Ona to the Meats Laboratory, University of Florida,
Gainesville. The overall mean shrink was 4.8%. Breed of sire was the
only source of variation that had a significant effect on shrink. Calves
Table 2. Mean squares from variance analyses for growth traits, slaughter data, and qualitative carcass traits.
Chilled Ribeye/
Standardized Carcass Intransit Dressing 100-lb
Source DF Daily Gain Weight Shrink % Carcass FOEt KPHt
Year 10 .42** 14472** 23.55** 28.01** .0011* .06** 2.41**
Sire 2 .53** 63990** 11.28** 26.60** .0046** .34** 3.34**
Dam 2 1.64** 122805** 3.35 18.38** .0014* .43** 2.13**
SxD 4 1.59** 77685** .85 19.62** .0023** .05** 3.52**
Age-B-linear 1 .01 252924** 22.27** 21.22** .0051** .19** 6.65**
Remainder 332 .09 2323 1.58 2.62 .0005 .01 .33
SEstimated
Carcass Carcass
Source DF Yield Maturity
Year 10 6.03** 3.91**
Sire 2 53.71** .11
Dam 2 26.35** .39
SxD 4 3.90* .36
Age-B-linear 1 22.22** .01
Remainder 332 1.08 .16
tFat over ribeye.
tKidney, pelvic, and heart fat %.
ttWarner-Bratzler shear force, lb.
*Significantly different at P<0.05.
**Significantly different at P<0.01.
Carcass
Conformation
6.82**
34.48**
52.85**
2.72
15.43**
1.21
Degree
of
Marbling
39.01**
232.44**
158.27**
9.55
217.49**
13.46
13.46 1.60
Carcass
Quality
Grade
Grade
14.00**
33.30**
61.63**
2.90
38.26**
1.6(0
Panel
WBS Tenderness
99.62** 6.67**
35.32* 11.94**
79.72** 20.18**
3.19 .21
1.96 .00
7.99 .82
from Charolais sires had a lower intransit shrink than either Angus
or Brahman sired calves (Table 3).
Observed dressing percent based on chilled carcass weight and
liveweight at the slaughter plant ranged from 60.4% for Angus steers
to 63.1% for the Brahman x Charolais steers. As anticipated, dres-
sing percent tended to be positively associated with carcass weight.
Heterosis levels for dressing percent were low, averaging 2.6% for
A-B, 0.9% for A-C, and 1.2% for C-B reciprocal crosses. None of these
levels were significant.
Ribeye area per 100 lb carcass weight. Total ribeye area (REA) is
associated with carcass weight. Therefore, to determine relative
meatinesss," the ribeye area data were adjusted for carcass weight.
Ribeye area per 100 lb carcass showed (P< 0.01) straightbred Angus
carcasses to be meatier (2.09 in2/100 lb [29.72 cm2/100 kg]) than
Brahman (1.96 in2/100 lb [27.87 cm2/100 kg]) and similar to Charo-
lais carcasses (2.03 in2!100 lb [28.87 cm2/100 kg]). The Angus had
some advantage for meatinesss" by virtue oflighter weight carcasses.
Significant differences (P< 0.01) existed among sire breeds. Charo-
lais carcasses ranked first in REA with 2.01 in2/100 lb (28.58 cm2/100
kg), followed by the Angus carcasses at 1.98 in2/100 lb (28.16 cm2/100
kg). Angus dams produced calves with the largest (P< 0.01) ribeye
area per unit of carcass weight for dam breeds. The Charolais x
Angus calves had larger (P< 0.01) relative ribeye area than the AC
calves, and the CB calves had a larger (P< 0.05) relative ribeye area
than the BC reciprocal calves (Table 3). No difference existed between
the A-B reciprocals. Heterosis levels for adjusted ribeye area were
negative and significant for the combined reciprocals, being -6.0%
(P< 0.01) for A-B, 4.3% (P< 0.05) for A-C, and 5.0% (P< 0.05) for
C-B reciprocals.
Fat over eye. This trait (FOE) is extremely important in modern
beef cattle production because of its positive relationship with car-
cass quality and yield grades. In this study, FOE ranged from a low of
0.18 in (0.46 cm) for Charolais steers to 0.42 in (1.07 cm) for BA
steers. Breed rankings in descending order for the purebreds, breed of
sire, and breed of dam classifications all were in the order of Angus,
Brahman, and Charolais. Interestingly, heterosis for FOE was posi-
tive for all breed crosses, amounting to 21.7%, 2.0%, and 9.6% respec-
tively for the A-B, A-C, and B-C reciprocal crosses. These values gen-
erally paralleled heterosis for the growth traits, reflecting an overall
superiority for performance in the crossbreds. Except for the influ-
ence of heterosis, genetic potential for growth tended to be negative-
ly associated with measurements of fatness.
Kidney, pelvic, and heart fat percent. The kidney, pelvic, and heart
(KPH) fat percent is one of the components used in estimating per-
cent yield. Significant (P< 0.01) differences were measured for breed
Table 3. Least squares mating group means and direct estimates of calf heterosis for growth traits and slaughter data.
Standarized
Least squares means
Breed Subclasses
AATT
BB
CC
AB
BA
AC
CA
BC
CB
Breed of Sire
A
B
C
Significance
Breed of Dam
A
B
C
Significance
Initial
Weight
(lb)t
488
387
445
540
484
489
504
467
535
540
Daily
Gain
(lb)t
2.17
1.90
1.83
2.31
2.14
2.34
2.27
2.19
2.33
2.24
2.10
2.17
2.24
**
2.14
2.07
2.30
**
Final
Weight
(lb)t
869
720
767
947
860
900
904
851
944
933
Chilled
Carcass
Weight
(lb)t
521.4
431.9
460.1
567.2
516.2
539.8
542.5
511.1
565.9
558.3
828 496.9
870 521.9
910 545.5
** **
494.2
511.5
558.5
**
Intransit
Shrink
(%)
4.77
4.94
5.10
4.48
4.80
4.63
5.12
4.10
5.27
4.45
4.95
5.0
4.34
**
4.56
4.79
4.96
ns
Dressing REA/100-lb
% Carcass
(%)
61.9
60.4
61.4
61.9
62.0
63.0
62.1
61.2
63.1
61.6
61.5
62.5
61.6
**
61.6
61.7
62.4
**
FOE KPH
(in2)1 (in)tt
1.96 .29
2.09
1.96
2.03
1.95
1.86
1.90
2.05
1.84
1.95
1.98
1.89
2.01
**
2.00
1.95
1.92
*
Estimated
Carcass
Yield
(%)
50.9
50.5
50.8
52.3
50.5
49.6
51.1
51.1
50.6
51.7
50.7
50.4
51.7
*'
50.4
51.0
51.4
**
Table 3. Continued.
Standarized
Initial Daily Final
Weight Gain Weight
Chilled
Carcass
Weight
Intransit Dressing REA/100-lb
Shrink % Carcass
FOE
Estimated
Carcass
KPH Yield
Heterosis in Units
AB + BA/2
AC + CA/2
BC + CB/2
71**
22*
45**
Heterosis in %
Fi (AB) 16.9
Fi (AC) 4.7
Fi (BC) 9.1
tkg = x x 0.454
4cm2/100 kg = x 14.22
ttcm = x x 2.54
#tBreed designation: A= Angus, B=
Reciprocals combined.
Kidney, pelvic, and heart fat, %.
*Significantly different at P<0.05.
**Significantly different at P<0.01.
136**
45**
83**
82.0**
27.2**
49.5**
-.34
-.10
.07
20.1 18.3 18.4 -6.5
5.9 5.4 5.5 -2.2
10.4 9.7 9.4 1.5
Brahman, C= Charolais. Breed of sire first letter.
.51**
.33**
.37**
18.3
12.3
14.2
1.6**
.5
.7*
2.6
.9
1.2
-.12**
-.08*
-.09**
-6.0
-4.3
-5.0
.07**
.01
.02
21.7
2.0
9.6
.56**
-.29
-.40*
-1.1
-.5
-.7
.37**
.20**
.22**
of sire, breed of dam, and breed of sire x breed of dam interactions (Ta-
ble 2.) Straightbred Angus carcasses had a higher KPH fat % (P<
0.05) than Charolais, with Brahman being intermediate (Table 3).
Carcasses of steers sired by Charolais bulls had less KPH fat % than
carcasses of steers from Brahman (P< 0.01) and Angus (P< 0.05)
sires. Carcasses of steers from Charolais dams had a higher KPH fat
% (P< 0.01) than carcasses from Angus dams but were similar to car-
casses from Brahman dams. Brahman sires and Angus dams contrib-
uted more to KPH fat % than Charolais sires or dams, Brahman
dams, or Angus sires. The C-B reciprocals were the only F1 combina-
tions that showed a difference for KPH % (P< 0.01), being 3.26% for
BC and 2.76% for CB. Heterosis levels for KPH fat % among Fi com-
binations were 18.3% (P< 0.01) for A-B, 12.3% (P< 0.01) for A-C, and
14.2% (P< 0,01) for C-B.
Estimated yield. Differences in estimated yield of closely trimmed
boneless cuts were significant for all main effects (P< 0.01) and for
breed of sire x breed of dam interaction (P< 0.05). The values were
similar for straightbred Angus and Brahman carcasses (50.5% and
50.8%) with the Charolais carcasses being somewhat higher (52.3%).
Breed of sire effects were highly significant, with Charolais sires pro-
ducing carcasses with the highest yield (51.7%), followed by the An-
gus (50.7%) and Brahman (50.4%). Breed of dam effects (Table 3)
showed Charolais dams to be highest (51.4%), with Brahman dams
next (51.0%) and Angus dams lowest (50.4%). Research in Missouri
(Hedrick et al., 3) showed the Charolais to have a higher yield of re-
tail cuts than the Angus or Hereford.
Differences between AB-BA and CB-BC reciprocal combinations in
this study were significant; however, the AC and CA combinations
were similar. Heterosis levels for estimated percent yield were nega-
tive for the combined reciprocals. Negative heterosis levels were
-1.1% for A-B (P< 0.01), -0.7% for B-C (P< 0.05), and -0.5%
(nonsignificant) for A-C reciprocals (Table 3).
Qualitative Carcass Traits
There were no significant breed of sire x breed of dam interactions
for carcass quality traits (Table 2). Except for maturity, both breed of
sire and breed of dam effects were significant (P< 0.01) for all quali-
tative carcass traits. The least squares means and heterosis levels for
qualitative carcass traits are given in Table 4.
Maturity score. Carcass maturity score reflects the physiological
age of cattle. It is one of the components, along with conformation
and marbling, that determines final carcass quality grade. Animals
in this study averaged 440 days of age when slaughtered; thus the
steer carcasses were classified A- or A in maturity (Table 4). The
mean carcass maturity score was 1.6, with variations from 1.4 for
straightbred Angus to 1.7 for the Angus x Brahman cross.
Conformation score. Conformation was based on thickness of mus-
cling and overall thickness and fullness of the carcasses in relation to
length. Both breed of sire and breed of dam had significant (P< 0.01)
effects on conformation score (Table 2). The mean conformation score
was 15.8, ranging from 14.4 for straightbred Brahman to 17.2 for
straightbred Angus (P< 0.01). Straightbred Charolais at 15.2 was
lower (P< 0.01) than the Angus. Calves by both Angus sires and
dams had carcasses with higher conformation scores (P< 0.01) than
either the Brahman or the Charolais. However, carcasses of steers
from Charolais dams had higher (P< 0.01) conformation scores than
those from Brahman dams. Both Angus sires and dams excelled in
producing steer carcasses with high conformation scores.
Marbling score. Marbling intramuscularr fat) in the longissimus,
is the most important trait determining carcass quality grade. The
mean marbling score was 9.2, ranging from 6.8 for straightbred
Charolais to 12.0 (P< 0.01) for straightbred Angus. Straightbred
Brahman carcasses were slightly higher in marbling score than the
Charolais carcasses (7.9 vs 6.8). The Angus-sired carcasses had a
higher marbling score (P< 0.01) than Brahman-sired carcasses,
which in turn were higher (P< 0.01) than the Charolais-sired car-
casses. Angus dams produced steer carcasses with higher (P< 0.01)
marbling scores than either Brahman or Charolais dams, which pro-
duced carcasses with similar marbling. There were no differences in
the marbling scores between any of the reciprocal Fi carcasses. Of the
three breeds, the Angus breed excelled for marbling score by a wide
margin, followed by the Brahman with the Charolais last.
Carcass quality grade. Quality grade was based on separate
evaluation of marbling, conformation, skeletal maturity, and charac-
teristics of the lean tissue, i.e., firmness, color and texture. Signifi-
cant differences (P< 0.01) were observed for carcass quality grade
among breed groups, breed of sire, and breed of dam (Table 2).
Straightbred Angus excelled (P< 0.01) in carcass quality grade with
a score of 16.1 compared with 13.8 for straightbred Brahman and 13.4
for Charolais (Table 4). Both breed of sire and dam effects were high-
est for the Angus, with Brahman next and Charolais last. No differ-
ence was measured in the carcass quality grade between Charolais
and Brahman dams; however, the difference between Brahman sires
and Charolais sires was significant (P< 0.01). Among breed crosses,
A-B reciprocals had higher grades than either the C-B (P< 0.01) or
the A-C (P< 0.05) combinations at 15.1%, 14.1%, and 14.6%, respec-
tively. Carcass grades of A-C reciprocals were higher (P< 0.05) than
Table 4. Least square mating group means and direct estimates of calf heterosis for qualitative carcass traits.
Carcass
Carcass Carcass Degree of Quality
Maturity Conformation Marbling Grade WBSt(lb)
Least squares means 1.6
Breed Subclass
AAt 1.4
BB 1.5
CC 1.6
AB 1.7
BA 1.5
AC 1.6
CA 1.6
BC 1.5
CB 1.6
Breed of sire
A 1.6
S B 1.5
0 C 1.6
Significance ns
Breed of dam
A 1.5
B 1.6
C 1.6
Significance ns
Heterosis in Units
AB + BA/2 .18
AC + CA/2 .12
BC + CB/2 .07
Heterosis in %
Fi (AB) 12.5
Fi (AC) 8.1
Fi (BC) 1.0
tBreed designation: A=Angus, B=Brahman, C
tWarner-Bratzler shear force, lb.
ns= nonsignificant
**Significantly different at P<0.01.
15.8 9.2 14.5 11.3
17.2
14.4
15.2
15.8
16.2
16.2
16.2
15.5
15.1
16.4
15.4
15.5
**
16.5
15.1
15.7
**
.22
-.03
.49
12.0
7.9
6.8
10.5
10.8
9.7
9.1
8.8
7.4
10.7
9.2
7.8
**
10.6
8.6
8.4
**
.17
.00
.79
1.4 6.7
-.2 .0
3.3 10.8
=Charolais. Breed of sire first letter.
16.1
13.8
13.4
14.7
15.4
14.4
14.8
14.4
13.8
15.1
14.6
14.0
**
15.4
14.1
14.1
**
.10
-.13
.49
.7
-.9
3.6
9.7
13.0
11.1
11.8
11.1
11.3
10.2
11.8
11.5
10.9
11.9
11.0
**
10.3
12.1
11.4
**
.08
.32
.40
.7
3.1
3.5
Panel
Tenderness
5.1
6.0
4.4
5.2
5.0
5.2
5.2
5.7
4.5
4.9
5.4
4.7
5.3
**
5.6
4.8
5.0
**
carcass grades of C-B reciprocals. These results express the genetic
merit of the Angus, Brahman, and Charolais breeds for carcass qual-
ity, with Angus first, Brahman second, and Charolais last, with a
narrow difference between the Charolais and Brahman.
The carcass grade differences between both A-B and B-C reciprocal
matings were significant (P< 0.05), but nonsignificant for A-C recip-
rocals. The BA combinations had higher carcass grades than the AB,
and BC higher than CB combinations. These differences were associ-
ated with maternal effects of the Angus and Charolais compared to
Brahman dams relative to fattening qualities of offspring (Peacock et
al., 8).
Warner-Bratzler shear. Warner-Bratzler (W-B) shear force of
1.27-cm cores provides a measure of tenderness. With broiled steak,
the mean W-B shear value was 11.3 lb varying from 9.7 Ib for
straightbred Angus to 13.0 lb for straightbred Brahman (P< 0.01).
Angus steaks had significantly lower (P< 0.05) shear values than
Charolais steaks, while the Charolais steaks were lower than Brah-
man steaks. Broiled steaks from Angus sired steers had lower
(P< 0.01) shear values than steaks from Brahman sires. Charolais-
sired carcasses were similar to Angus-sired carcasses but lower
(P< 0.01) than those from Brahman sires. Angus dams produced
steaks with lower (P< 0.01) shear values than Brahman or Charolais
dams, with the Brahman and Charolais dams having similar values
for this trait. Warner-Bratzler shear values were lowest for the An-
gus breed, next for Charolais, and highest for the Brahman, with no
differences existing between Fi reciprocals. No significant heterosis
was exhibited for W-B shear values in this study, whereas Hedrick et
al. (3) showed a highly significant heterosis level for the Charolais-
Angus Fi reciprocal for tenderness.
Tenderness score. The mean score for tenderness by taste panel in
this study was 5.1 (Table 4). Distinct variations (P< 0.01) occurred
among the straightbred steer carcasses, being 6.0 for Angus, 5.2 for
Charolais, and 4.4 for Brahman.The only significant difference be-
tween Fi reciprocals was the tenderness score of 5.7 for CA compared
with 5.2 for the AC carcasses (P< 0.05). Angus and Charolais sires
produced steer carcasses that were similar in tenderness but more
tender (P< 0.01) than Brahman-sired carcasses. Angus dams pro-
duced steer carcasses that were more tender than those produced by
Brahman and Charolais dams (P< 0.01). Breed effects for taste panel
tenderness scores were highly correlated with Warner-Bratzler shear
value scores. The Angus was most tender, with Charolais next, and
Brahman in last place.
SUMMARY
Data have been presented on 352 Angus, Brahman, Charolais, and
reciprocal Fi crossbred steers fattened in feedlot. Finished steers
were slaughtered and their carcasses evaluated. Significant differ-
ences were found among sire breeds and dam breeds for all traits
measured except carcass maturity and intransit shrink.
Straightbred Charolais steers had the highest scores for daily gain,
dressing percent, chilled carcass weight, and estimated percent yield,
and had lowest fat over the ribeye of the straightbreds. Straightbred
Angus steers had the largest ribeye area per 100 lb carcass weight,
most fat over the ribeye, highest conformation score, highest mar-
bling score, highest USDA quality grade, lowest Warner-Bratzler
shear score, and highest taste panel tenderness score. Straightbred
Brahman steers had the lowest taste panel tenderness score. Brah-
man and Charolais steers had similar ribeye areas per 100 lb carcass
weight, marbling scores, and USDA quality grades. Brahman and
Angus steers had similar weight gains, dressing percent, chilled car-
cass weights, and estimated percent yield.
Sire and dam breed effects were similar to the straightbred breed
effects; the Charolais excelled in quantitative traits and Angus in
qualitative traits.
Significant breed of sire x breed of dam interactions existed for all
quantitative traits, with significant heterosis levels of Fi progeny for
all quantitative traits. The highest heterosis levels were from Angus-
Brahman crosses, followed by Charolais-Brahman and Angus-
Charolais. Heterosis levels for estimated percent yield and ribeye
area per 100 lb carcass were negative but significant, with AB high-
est and AC lowest. There were no significant breed of sire x breed of
dam interactions for qualitative traits, indicating that breed effects
for qualitative traits are additive.
LITERATURE CITED
1. Gregory, K. E., L. A. Swiger, L. J. Sumption, R. M. Koch, J. E. Ingalls, W.
W. Rowden, and J. A. Roghlisberger. 1966. Heterosis effects on carcass
traits of beef cattle. J. Anim. Sci. 25:311.
2. Harvey, W. R. 1975. Least-squares analyses of data with unequal sub-
class numbers. USDA ARS H-4.
3. Hedrick, H. B., G. F. Krause, J. F. Lasley, Bob Sibbit, L. Langford, and A.
J. Dyer. 1975. Quantitative and qualitative carcass characteristics of
straightbred and reciprocally crossed Angus, Charolais and Hereford
steers. J. Anim. Sci. 41:1581.
4. Hedrick, H. B., J. F Lasley, J. P. Jain, G. F. Krause, Bob Sibbit, L. Lang-
ford, J. E. Comfort, and A. J. Dyer. 1970. Quantitative carcass character-
istics of reciprocally crossed Angus, Charolais and Hereford heifers. J.
Anim. Sci. 31:633.
5. Koch, R. M., M. E. Dikeman, D. M. Allen, M. May, J. D. Crouse, and D. R.
Campion. 1976. Characterization of Biological Types of Cattle. III. Car-
cass composition, quality and palatability. J. Anim. Sci. 43:48.
6. Koch, Robert M., and Michael E. Dikeman. 1977. Characterization of Bio-
logical Types of Cattle. V. Carcass wholesale cut composition. J. Anim.
Sci. 45:30.
7. Lasley, J. F., G. F Krause, J. P. Jain, H. B. Hedrick, Bob Sibbit, L. Lang-
ford, and A. J. Dyer. 1971. Carcass quality characteristics in heifers of re-
ciprocal crosses of the Angus, Charolais, and Hereford breeds. J. Anim.
Sci. 32:406.
8. Peacock, F. M., A. Z. Palmer, J. W. Carpenter, and M. Koger. 1979. Breed
and heterosis effects on carcass characteristics of Angus, Brahman, Char-
olais and crossbred steers. J. Anim. Sci. (In press).
All programs and related activities sponsored or assisted by the Florida
Agricultural Experiment Stations are open to all persons regardless of race,
color, national origin, age, sex, or handicap.
|
