JAY, ARC RESEARCH REPORT WF82-1 January, 1982
BEEF PRODUCTION WITH BEEF STEERS OF DIFFERENT BREEDING ON COOL-SEASON
ANNUAL PASTURES FOLLOWED BY A PERIOD OF FEEDLOT FEEDING
J. E. Bertrand, L. S. Dunavin, and R. L. West-/
Steers of Charolais breeding grazing cool-season annual pastures (a mixture
of rye, ryegrass, and crimson clover) gained (P<0.05) faster than steers of Brit-
ish breeding for a 134-day period (2.16 versus 1.90 lb./head/day, respectively).
The gain per acre (477 lb.) was higher for steers of Charolais breeding than that
(454 lb.) of steers of British breeding. Therefore, the cost of gain on pasture
was lower for steers of Charolais breeding than that of steers of British breeding
($24.86 versus $26.12/cwt, respectively). The off grazing cost per hundredweight
was $2.19 lower for steers of Charolais breeding.
During the feedlot period of 131 days, the performance data were similar for
steers of British and Charolais breeding. The carcasses of steers of British
breeding graded slightly higher and had more fat and less lean meat than those of
steers of Charolais breeding. However, the differences in slaughter and carcass
parameters were not great and were not significantly different. The feed cost per
hundredweight gain in the feedlot for steers of Charolais breeding was slightly
lower than that for steers of British breeding ($53.10 versus $53.50, respective-
ly). Gain on pasture, which affected off grazing cost and carcass weight at the
end of the feeding period, was the primary contributors totd at4" er e" it
return per head; the steers of Charolais breeding we 4 o fi2~i.9 /
.OBJECTIVE FLb I
The study discussed in this report was undertaken w.tA hSeUjj iA I c 0io' -
tive in mind:---
1. To compare the performance, slaughter, carcass, and economic data with
beef steers of different breeding (British versus Charolais) grazing
cool-season annual pastures followed by a period of feedlot feeding.
Thirty-two lightweight (average 445 lb.) feeder steers, grading U. S. Good
or better and each treated with a 36 mg ear implant of RALGRO (Zeranol a protein
anabolic agent), were weighed and allotted at random from breed groups to four
experimental groups of eight steers each. The four experimental groups, utilizing
two groups (replicates) per treatment, were assigned to two treatments on pasture:
1) British breeding [Angus, Hereford, and crosses (Angus X Hereford)] and 2)
Charolais breeding [Charolais and Charolais crosses (Charolais X Hereford and
1/Animal Scientist and Associate Agronomist, respectively, Agricultural Research
Center, Jay, and Associate Meat Scientist, Animal Science Department, Gaines-
The pastures consisted of a mixture of 'Wrens abruzzi' rye, 'Gulf' ryegrass,
and 'Dixie' crimson clover. Each group of eight initial animals grazed four 1.25
acre plots in a rotational system.
The rye was planted in row widths of 7 inches with a grain drill at the rate
of 83 lb. per acre. The ryegrass and crimson clover were top-seeded over the rye
with a cultipacker-seeder at the rates of 12.5 and 9.5 lb. per acre, respectively.
All pastures were planted on October 21 and 22, 1980. A complete fertilizer (8-24-
24) was applied to all pastures at planting time at the rate of 250 lb. per acre.
Three applications of 100 lb. per acre each of ammonium nitrate were made during
the grazing season.
Grazing began on December 16, 1980 and was terminated when the forage was
essentially grazed out (April 29, 1981). Individual animal weights were taken
after an overnight shrink (fast from feed and water) at the beginning and end of
the pasture phase. Check weights by groups were obtained every 28 days during the
period. Additional grazer animals of the same type, breeding, and size were added
and removed as needed to keep the forage uniformly grazed. Each experimental group
of steers was rotated between the four pasture plots assigned to it as required
for best utilization of good quality forage.
The proximate analysis of the pasture forage is listed in Table 1.
At the end of the pasture phase, the steers were each retreated with a 36 mg
ear implant of RALGRO and fed by experimental groups in the feedlot for a period
of 131 days (April 29 to September 7, 1981). The feedlot diet, composed of 46%
corn silage, 50% ground corn, and 4% concentrate supplement mixture on an as-fed
basis (24, 70, and 6% on a dry matter basis, respectively), was fed ad libitum
Individual animal weights in the feedlot were taken after an overnight shrink
at the beginning and end of the feedlot phase. Check weights by groups were again
obtained every 28 days.
A mineral mixture (consisting of two parts dicalcium/monocalcium phosphate
and one part trace-mineralized salt), plain salt, and clean drinking water were
available to the animals at all times during both the pasture and feedlot phases.
The composition and cost of the concentrate supplement mixture fed during the
feedlot phase are listed in Table 2. The proximate analyses of the ground corn,
corn silage, and concentrate supplement mixture are listed in Table 1.
The animals were slaughtered at the end of the feedlot phase at the University
of Florida Meats Laboratory, Gainesville. Slaughter and carcass data were determined
by a federal grader and trained personnel at the Meats Laboratory.
Analyses of variance on performance, slaughter, and carcass parameters where
appropriate for the pasture and feedlot phases of the trial were conducted accord-
ing to the method of Snedecor (1946).
The performance and economic data for growing beef steers of different breed-
ing grazing cool-season annual pastures are presented in Table 3. Steers of
Charolais breeding gained (P<0.05) faster than steers of British breeding for a
134-day grazing period (2.16 versus 1.90 lb./head/day, respectively). The beef
gain per acre was 477 lb. for steers of Charolais breeding and 454 lb. for steers
of British breeding. The stocking rate per acre was slightly higher for steers of
British breeding. However, because of a more rapid daily gain, steers of Charolais
breeding had a slightly larger gain per acre per day than steers of British breed-
ing (3.56 versus 3.38, b., respectively).
The cost of gain on pasture was lower for steers of Charolais breeding than
that of steers of British breeding ($24.86 versus $26.12/cwt, respectively). (Table
3). The off grazing cost per hundredweight was $2.19 lower for steers of Charolais
breeding. Since the purchase cost initially was the same for all steers, steers of
Charolais breeding had a lower off grazing cost per hundredweight due to a more
rapid daily gain.
Performance, slaughter, and carcass data for beef steers of different breed-
ing off cool-season annual pastures followed by a period of feedlot feeding are
presented in Table 4. The daily gain, efficiency of converting feed to gain, and
feed consumption for the 131-day feedlot period were similar for steers of British
and Charolais breeding. The above mentioned performance data for steers of both
treatments in the feedlot were not as good as obtained in previous studies. This
was probably due to the constant high temperature and humidity which occurred
during the summer of 1981.
The carcasses of steers of British breeding graded slightly higher and had
more fat and less lean meat than those of steers of Charolais breeding (Table 4).
These differences were not great. In fact, the carcass and slaughter parameters
were not significantly different between the two treatments.
The economic data for beef steers of different breeding off cool-season
annual pastures followed by a period of feedlot feeding are presented in Table 5.
The feed cost per hundredweight gain in the feedlot for steers of Charolais breed-
ing was slightly lower than that for'steers of British breeding ($53.10 versus
$53.50/cwt, respectively). Gain on pasture, which affected off grazing cost and
carcass weight at the end of the feeding period, was the primary contributor to
the difference in net return per head; the steers of Charolais breeding were more
- 3 -
Proximate Analyses of the Pasture Forage, Ground Corn, Corn Silage, and
Concentrate Supplement Mixture (1980-81) ARC, Jay
Pasture Groun d Cor Concentrate
Item forage a) corn(b) silage(b) supp. mix.(b)
Moisture, % 83.18 11.96 67.28 12.66
Crude protein, % 4.33 9.33 2.84 46.42
Ash, % 1.55 1.61 1.22 25.80
Ether extract, % 0.94 4.05 1.35 2,68
Crude fiber, % 3.40 4.55 9.77 4.87
Nitrogen-free extract, % 6.60 68.50 17.54 7.57
(a)'Wrens abruzzi' rye, 'Gulf' ryegrass, and 'Dixie' crimson clover mix-
ture (average of five hand-plucked samples collected at intervals
(during the pasture phase).
(b)Average of four samples collected at intervals during the feedlot
Composition and Cost of the Concentrate Supplement Mixture (1980-81) ARC, Jay
Ingredients % Lb./ton Cost(a)
Soybean meal (44% protein) 62.66 1253 $190.46
Urea 45% N 10.71 214 19.26
Dicalcium/monocalcium phosphate 6.98 140 19.32
Ground limestone 10.71 214 6.96
Salt (trace-mineralized) 8.94 179 13.43
Vitamin A supplement(b) + + 1.53
Total 100.00 2000 $265.96
(a)Based on the following prices: soybean meal (44% protein) = $304.00/ton, urea
45% N = $180.00/ton, dicalcium/monocalcium phosphate = $276.00/ton, ground
limestone = $65.00/ton, salt (trace-mineralized) = $150.00/ton, and Rovimix
,A-650 (vitamin A supplement containing 650,000 IU/g) = $6.00/1b.
b)Rovimix A-650 (vitamin A supplement containing 650,000 IU/g) added at the
level of 75 million IU/ton or 37,500 IU/lb. of concentrate supplement mixture.
(c)Mixing, milling, overage, storage, etc.---$15.00/ton.
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Performance and Economic Data for Growing Beef Steers of. Different Breeding
Grazing Cool-Season Annual Pastures (1980-81) ARC, Jay( a).
Item breedi breeng c)
Initial no. of animals 16t() 16
Length of grazing, days 134 134
Avg initial wt, lb. 445 446
Avg final wt, lb. 699 735
Avg gain/animal, lb. 254 289
Avg daily gain, Ib. 1.90 2.16*
Gain/acre, lb. 454 477
Animal days/acre(e) 239 221
Stocking rate/acre(e) 1.78 1.65
Gain/acre/day, lb. 3.38 3.56
Pasture cost/cwt gain (f $ 26.12 $ 24.86
Avg cost/head of feeder(g) $369.93 $370.76
Pasture cost/head of feeder(f) $ 66.34 $ 71.85
Total cost/head of feeder(h) $436.27 $442.61
Off grazing cost/cwt h) $ 62.41 $ 60.22
(a)Rotational grazing of a mixture of 'Wrens abruzzi' rye, 'Gulf' ryegrass,
Sand 'Dixie' crimson clover.
b Angus, Hereford, and crosses (Angus X Hereford).
jMainly Charolais breeding.
(d)Initially, two groups of eight steer calves each.
(e)Additional grazer animals of the same breeding and size were added and
removed as needed to keep the forage uniformly grazed.
(fPasture cost = $118.57/acre.
(g)Calf cost = $83..13/cwt for steers (includes cost of animals, hauling,
,veterinary costs, feed, etc.).
(h)Does not include interest on investment, management, and labor involved
in caring for the animals.
*Significant at P<0.05.
Performance, Slaughter, and Carcass Data for Beef Steers of Different Breeding
Off Cool-Season Annual Pastures Followed by a Period of Feedlot Feeding
(1980-81) ARC, Jay
Item b ree di g(a) breeding(b)
No. of animals 16kc) 16
Feedlot period, days 131 131
Avg initial wt, lb. 699 735
Avg final wt, lb. 973 1009
Avg gain/animal, lb. 274 274
Avg daily gain, lb. 2.09 2.09
Feed/gain ratio 13.2 13.1
Feed/animal/day, lb. _27.5 27.3
Avg carcass quality gralded) 15.5 15.3
Avg carcass yield gradeMe) 2.9 2.5
Avg marbling scorer ) 10.4 10.5
Avg color of lean.g) 3.9 4.1
Avg color of fat h) 2.0 2.1
Avg fat over eye, inch 0.46 0.37
Rib eye area, sq. inch 10.60 11.32
Avg hot carcass wt, lb. 577 604
Ava dressing percent (carcass vield) 59.3 59.9
(a)Angus, Hereford, and crosses (Angus X Hereford)
(b)Mainly Charolais breeding.
(c)Two groups of eight steers each.
(d)12 = high Standard, 13 = low Good, 14 = average Good, 15 = high Good, 1E
low Choice, 17 = average Choice, etc.
(e)Yield grades numbered 1 through 5, with yield grade 1 representing the
highest yield of boneless, closely trimmed retail cuts (cutability) and
yield grade 5 the lowest.
(f8 = slight, 9 = slight+, 10 = small-, 11 = small0, 12 = small+, 13 =
(9)3 = light cherry red, 4 = cherry red, 5 = moderately dark red, etc.
(h)1 = white, 2 = cream, 3 = slightly yellow, and 4 = very yellow.
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" .' . # r . . # -
Economic Data for Beef Steers of Different Breeding Off Cool-Season Annual
Pastures Followed by a Period of Feedlot Feeding (1980-81) ARC, Jay
Item breeding(a) breeding(b)
Feedlot period, days, 131 131
Feed cost/cwt feedlot ,gin(c) $ 53.50 $ 53.10
Off grazing cost/head(a $436.27 $442.61
Avg feed cost/head $146.59 $145.49
Total cost/head(d) $582.86 $588.10
Avg final value/head(e) $592.09 $612.32
Net return/head(d) $ 9.23 $ 24.22
Avg price/cwt on foot $ 60.85 $ 60.69
Avg price/cwt carcass $102.62 $101.38
(a)Angus, Hereford, and crosses (Angus X Hereford).
(b)Mainly Charolais breeding.
(C)Corn silage cost = $25.00/ton, ground corn cost.= $117.85/ton, and con-
centrate supplement mixture cost = $265.96/ton (Feedlot ration cost =
$81.06/ton on an as-fed basis).
(d)Does not include labor involved in feeding and caring for animals.
(e)prices used for carcass value calculations: Prime 2, 3, and 4 500 to
700 lb. = $104./cwt; Choice 2 400 to 500 lb. = $104./cwt; Choice 3 -
400 to 500 lb. = $102./cwt; Choice 4 400 to 500 lb. = $93./cwt; Choice
2 500 to 800 lb. = $106./cwt; Choice 3 500 to 800 lb. = $104./cwt;
Choice 4 500 to 800 lb. = $95./cwt; Good 2 and 3 400 to 500 lb. =
$99./cwt; Good 2 and 3 500 to 800 lb. = $101./cwt; Standard 2 and 3 -
400 to 500 lb. = $94./cwt; and Standard 2 and 3 500 to 800 lb. =