Young bulls are finished during 260 days at open feedlot with capacity of 500 feeders and pen size of 40 to 100 head. Rearing program included some measures to prevent the stresses. On average daily DM intake was 7.9 kg/head, ADG - 1250 g, feed conversion 6.32 kg/kg BW gain, hot carcass weight - 349.6 kg, dressing yield - 58.2%. The main advantages of bull carcasses in comparison with steer (accordance with our review of many studies) are the low internal fat content (5.7 vs 14 kg) and fat trim (9.7 vs 50 to 87 kg), high content of edible parts of carcass (82.35 vs 80.0%) and more desirable amino-acid composition and ratio saturated fatty acid/polyunsaturated fatty acid. The best cuts for fast cooking of bull carcasses consisted 18.9% of weight and 44.8% of market value. Fattening of bulls instead of steers is recommended for small feedlots and family farms.
fattening, meat productivity, intact young bulls, steers, carcass and beef quality
1. Legoshin G.P., Sharafeeva T.G. Otkorm molodnyaka krupnogo rogatogo skota na sovremennyh fidlotah. Prakticheskoe rukovodstvo. VIZh, Dubrovicy, 2013, s. 1-76.
2. Rotta P.P., Prado R.M., Prado I.N., Valero M.V., Visentairer J.V. and Silva R.R. The effects of genetic groups, nutrition, finishing systems and gender of Brazilian cattle on carcass characteristic and beef composition and appearance: a review. Asian-Aust., J. Anim. Sci., 2009, № 12: 1718-1734., Braziliya.
3. Aricetti J.A., Rotta P.P., Prado R.M., Perotto D., Moletta J.L., Matsushita M. and Prado I.N. Carcass characteristics, chemical composition and fatty acid profile of Longissimus Muscle of bulls and steers finished in a Pasture Systems. Asian-Aust. J.Anim. Sci., 2008, № 10: 1441-1448, Braziliya.
4. Cundiff L.V., Wheeler T.L., Gregory K.E., Shackelford S.D., Koohmaraie M., Thalman M. and Van Vleck L.D. Preliminary results from cycle VII of the cattle germplasm evaluation program at the Roman L. Hruska U.S. Meat animal research center. Progress report № 22, 2004, p.p. 1-14.
5. Wheeler T.L., Candiff L.D., Snowder G.D., Thallman R.M., Shackelford S.D. and Koohmarale M. Preliminary results from cycle VIII of the cattle germplasm evaluation program at the Roman L. Hruska U.S. Meat animal research center. Progress report № 23, USDA, 2006: 1-12.
6. Ahmed O., Miller M.F., Shackelford S.D., Johnson L.P., Williams S.E., Mc Cann M.A., Reagan J.O. Effect of hot-fat trimming on factors associated with the subprimal yield of beef carcasses. J. Anim. Sci., 1992, 70: 439-443.
7. Arboitte M.Z., Brondani I.L., Restle J., Freitas L.S., Pereira L.B., Cardoso G.S. Carcass characteristics of small and medium-frame Aberdeen Angus young steers. Acta Scientiarum. Animal Sciences, 2012, 34 № 1: 49-56, Braziliya.
8. Prado I.N., Passetti R.A., Rivaroli D.C., Ornaghi M.C., Souza K.A., Carvalho C.B., Perotto D., Moletta J.L. Carcass composition and cuts of bulls and steers fed with three concentrate levels in the diets. Asian-Australian J. Anim. Sci., 2015, 28, № 2: 1309-1316, Braziliya.
9. Hunt D.M., Henricks M., Skelley G.C. and Grimes L.W. Use of trenbolone acetate and estradiol in intact and castrated male cattle: effects on growth, serum hormones and carcass characteristics. J. Anim. Sci., 1991, 89: 2452-2462, SShA, Yuzhnaya Karolina.
10. Legoshin G.P, Afanasyeva E.S., Mogilenetz O.N., Sharafeeva T.G., Mamonov A.P. Modern intensive dairy beef production systems in Russia. Journal «Modern Applied Science», 2014, 8, 6: 170-177.
11. Reddy B.V., Sivakumar A.S., Jeong D.W., Woo Y.B., Park S.J., Byun J.Y., Kim C.H., Cho S.H. and Hwang I. Beef quality traits of heifer in comparison with steer, bull and cow at various feeding environments. «Animal Science Journal», 2015, 86: 1-16 (Yuzhnaya Koreya).
12. Seldeman S.C., Cross H.R., Oltjen R.R. and Schanbacher B.D. Utilization of the intact male for red meat production: a review. J. Anim. Sci., 1982, 55, № 4: 2-14, Minsel'hoz SShA, MARC, Clay, Nebraska.
13. Alberti P., Panea B., Safiudo C., Olleta J.L., Ripoll G., Eribjerg P., Christensen M., Gigli S., Failla S., Concetti S., Hocquette J.F., Jailler R., Rudel S., Renand G., Nute G.R., Richardson R.L., Williams J.L. Live weight, body size and carcass characteristics of young bulls of fifteen European breeds. Livestock Science, 2008, 114: 19-30. Italy, Ispaniya, Daniya, Angliya, Franciya.
14. Shevhuzhev A.F., Smakuev D.R., Kardanov A.M. Ispol'zovanie aberdin-angusskoy i simmental'skoy porod dlya proizvodstva govyadiny v usloviyah Karachaevo-Cherkesskoy respubliki. «Effektivnoe zhivotnovodstvo», 2012. № 3. S. 42-45.
15. Gutkin S.S., Mazurovskiy L.Z., Sirazetdinov F.H. Myasnaya produktivnost' i kachestvo myasa bychkov raznyh porod. «Myasnoe skotovodstvo i perspektivy ego razvitiya». Sb. nauchn. trudov VNIIMS, 2000. № 53. S. 51-58.
