of Breed of Sire on Performance and Carcass
Characteristics of Beef Cattle
Jon Schoonmaker and Vern Anderson
NDSU Carrington Research Extension Center
Worldwide, there are more than 250 breeds of beef cattle. Over 60 of these breeds are present in the United States and approximately 20 constitute a majority of the genetics utilized in the U.S. for commercial beef production. The breed, or combination of breeds used in a breeding program have a significant impact on the efficiency and profitability of the beef enterprise. Breed influences mature size, reproductive efficiency, and maternal ability of the cow, as well as growth rate and carcass characteristics of calves. Nutritional requirements and production costs are also related to breed. Therefore selecting appropriate breeds to be used in a breeding program is an important decision for beef cattle producers.
In the past 25 years, considerable research has been conducted to characterize and compare the major beef breeds in the U.S. The most comprehensive studies have been conducted at the U.S. Meat Animal Research Center in Clay Center, NE. Since 1970, over 30 breeds have been evaluated in a common environment and management system for various performance traits (Cundiff et al., 2004). The report presented here describes breed differences seen on a much smaller population of animals located at the Carrington Research Extension Center.
Five sire breeds have been used at the Carrington Research Extension center dating back to 1987. Ten Hereford bulls and five Tarentaise bulls were used from 1987 to 1991, 24 Red Angus bulls were used from 1987 to 2004, 15 Limousin bulls were used from 1992 to 2001, and three South Devon bulls were used from 1998 to 2004. Sires were procured from area breeders and natural matings allowed for 45 to 50 days (from early June to mid July). Cows were bred to a different breed sire to maximize the positive traits of the breeds used in the cross. Cows calved from late February through early May. Cows were fed in open drylot pens with fenceline bunk feeding throughout the year. Cows were used in research trials evaluating feeding and management strategies at various times of the year. When not on a trial, cows were fed a least-cost ration consisting of co-product feeds available in the region.
All calves were weighed, and bull calves castrated within 48 hours of birth. Calves were weaned at approximately 170 days of age, and weights were adjusted to a constant age of 205 days. Heifers were retained, but were not used in research trials, thus growth data was not collected and little information is available on heifer calf performance. Steers were also retained and were randomly allotted, along with purchased calves, to various feedlot trial treatments. Steers were implanted and fed in open drylot pens. Steers were fed a growing ration for approximately three months with high grain finishing diets offered until marketing in April. Cattle were marketed and slaughtered at various packing plants. Carcass data was collected only in years when the research trial objectives were specifically linked to meat quality. Research protocols regarding animal care followed guidelines recommended in the Guide for the Care and Use of Agricultural Animals in Agricultural Research and Teaching (FASS, 1998).
Data were pooled across years and subjected to a one-way analysis of variance as a completely randomized design using the GLM procedures of SAS (Version 8.0; SAS Inst. Inc., Cary, NC). Planned pair-wise comparisons (least significant difference) were used to separate treatment least square means when the F-test was significant (P < 0.05). The model included effects due to breed of sire, and individual animal was the experimental unit.
Results and Discussion
Birth weight (781 steers and 800 heifers), weaning weight (539 steers), slaughter weight (444 steers), and carcass information (284 steers) for the various breed groups is summarized in Table 1. Limousin-sired bull and heifer calves were the heaviest (P < 0.01) at birth, whereas Hereford-sired calves were the lightest at birth; Red Angus-, South Devon-, and Tarentaise-sired bulls and heifers had birth weights intermediate to Limousin and Hereford. Tarentaise-sired calves were the heaviest (P < 0.01) at weaning, followed by Red Angus- and Limousin-sired calves; South Devon- and Hereford- sired calves were the lightest at weaning. Limousin-sired calves were the heaviest (P < 0.01) at slaughter, dressed the highest, and produced the heaviest carcasses. Red Angus-, South Devon-, Tarentaise-, and Hereford-sired calves ranked second, third, fourth, and fifth, respectively, for slaughter weight, hot carcass weight, and dressing percentage. Tarentaise- and Red Angus-sired calves produced the best marbled carcasses (P < 0.01); Hereford-, South Devon-, and Limousin-sired calves produced the least marbled carcasses. Limousin-sired calves produced carcasses with the largest rib-eye area (P < 0.01) followed by South Devon-sired calves. Red Angus- and Tarentaise- sired calves produced carcasses with the third largest rib-eye area; Hereford-sired calves produced carcasses with the smallest rib-eye area. Hereford-sired calves had the lowest percent KPH (P < 0.01); Limousin-, Red Angus-, and South Devon-sired calves had the greatest percent KPH. Tarentaise-sired calves had an intermediate amount of percent KPH . Limousin-sired calves produced carcasses that were the leanest at slaughter (P < 0.01) as evidenced by a low fat thickness and low yield grade. Red Angus-sired calves produced carcasses that were the fattest at slaughter. South Devon-, Tarentaise-, and Hereford-sired calves produced carcasses that were intermediate in fat level.
There are several criteria that should be taken into consideration when making breed selection decisions: production system, management ability, market demands, quantity and quality of feedstuffs available, climate, breed complementarity, and cost and availability of purebred seedstock. The breeds chosen should produce calves that are appropriate for their end use and optimize producer profitability. Cow-calf producers interested in raising replacement heifers may emphasize maternal traits such as milk production, mothering ability, calving ease, and small mature size. Producers selling weaned calves may want to use breeds that increase growth rate and weaning weights. Producers interested in retaining ownership of their cattle through slaughter may focus on breeds that increase muscle mass or breeds that improve marbling.
No one breed excels in all traits that are important for beef production. Crossbreeding systems that exploit heterosis and complementarity and match genetic potential with market targets, feed resources and climates provide the most effective means of breeding for production efficiency.
Cundiff, L. V., T. L. Wheeler, K. E. Gregory, S. D. Shackelford, M. Koohmaraie, R. M. Thallman, G. D. Snowder, and L. D. Van Vleck. Preliminary results from cycle VII of the cattle germplasm evaluation program at the Roman L. Hruska U. S. Meat Animal Research Center. 2004. Available on the internet at: http://www.marc.usda.gov/cattle/gpe/GPE22.pdf