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The effects of a combined androgenic-oestrogenic anabolic agent in steers and bulls 2. Muscle weight distribution, partition of body fat and carcass value

Published online by Cambridge University Press:  02 September 2010

J. D. Wood
Affiliation:
AFRC Food Research Institute — Bristol, Langford, Bristol BS18 7DY
A. V. Fisher
Affiliation:
AFRC Food Research Institute — Bristol, Langford, Bristol BS18 7DY
O. P. Whelehan
Affiliation:
AFRC Food Research Institute — Bristol, Langford, Bristol BS18 7DY
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Abstract

Twenty-one pairs of male cattle twins, 10 of which were monozygotic, were used in a study of the effects of a combined implant of trenbolone acetate (140 mg) and oestradiol-17β (20 mg) on muscle distribution, fat partition and carcass value. There were three comparisons within pairs: (1) between bulls and steers (no implants); (2) between bulls and implanted steers; and (3) between bulls and implanted bulls.

Implants were given twice, at 44 to 73 and 300 days of age, and animals were slaughtered at 400 days following ad libitum consumption of a complete pelleted diet. The effects of castration and/or implantation on muscle distribution, fat partition and carcass value were assessed by comparison with the untreated (control) bull values within each group and expressed as a ratio (treatedxontrol). These ratios were then compared between groups.

Implantation of steers increased slightly the weight of muscles in the neck which in a preliminary study had been shown to be particularly heavy in mature bulls compared with steers. Implantation therefore produced a more bull-like muscle distribution in steers and the effect in bulls was to increase the weight of these muscles even further. In steers and bulls the partition of body fat was not affected by implantation. Both implanted steers and bulls were fatter than their respective control bulls and their fat partition was appropriate to this (higher subcutaneous to intermuscular fat ratio).

Differences in carcass value between the groups, as evidenced by a retail cutting method applied to the right side of the carcass, reflected these differences in muscle distribution and fat partition. Thus, implantation of steers was judged to be economically advantageous despite the marginal reduction in value brought about by enlarged forequarter musculature. Implanted bull carcasses were less valuable than their respective controls mainly because they were fatter and required more trimming.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1986

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References

REFERENCES

Berg, R. T. and Butterfield, R. M. 1976. New Concepts of Cattle Growth, pp. 99119. Sydney University Press, Sydney.Google Scholar
Brannang, E. 1966. Studies on monozygous cattle twins. XVIII. The effect of castration and age of castration on the growth rate, feed conversion and carcase traits of Swedish Red and White cattle. Part I. LantbrHögsk. Annlr 32: 329415.Google Scholar
Brännäng, E. 1971. Studies on monozygous cattle twins. XXIII. The effect of castration and age of castration on the development of single muscles, bones and special sex characteristics. Part II. Swed. J. agric. Res. 1: 6978.Google Scholar
Brown, A. J., Coates, H. E. and Speight, B. S. 1978. A Photographic Guide to the Muscular and Skeletal Anatomy of the Beef Carcass. Meat Research Institute, Langford, Bristol.Google Scholar
Butler-Hogg, B. W. and Wood, J. D. 1982. The partition of body fat in British Friesian and Jersey steers. Anim. Prod. 35: 253262.Google Scholar
Butson, S., Patterson, D. L., Makarechian, M. and Price, M. A. 1983. The effect of Ralgro on feedlot performance and carcass characteristics of one year old bulls. 62nd A. Feeder's Day Rep. Univ. Alberta, Dep. Anim Sci., pp. 4852.Google Scholar
Cahill, V. R., Kunkle, L. E., Klosterman, E. W., Deatherage, F. E. and Wierbicki, E. 1956. Effect of diethylstilbestrol implantation on carcass composition and the weight of certain endocrine glands of steers and bulls. J. Anim. Sci. 15: 701709.CrossRefGoogle Scholar
Clegg, M. T. and Carroll, F. D. 1956. Further studies on the anabolic effect of stilbestrol in cattle as indicated by carcass composition. J. Anim. Sci. 15: 3747.CrossRefGoogle Scholar
Fisher, A. V. 1983. Variation in saleable meat yield and carcass value, as revealed by a UK method of commercial cutting, with particular regard to the comparison between bulls and steers. In Comparative Retail Value of Beef Carcasses (ed. Fisher, A. V.), EUR 8465 EN, pp. 2232. Commission of the European Communities, Luxembourg.Google Scholar
Fisher, A. V., Wood, J. D. and Tas, M. 1986a. Effects of some anabolic agents on the growth, carcass and tissue composition of barley-fed entire and castrated male Friesian cattle. Anim. Prod. 42: 195201.Google Scholar
Fisher, A. V., Wood, J. D. and Whelehan, O. P. 1986b. The effect of a combined androgenic-oestrogenic anabolic agent in steers and bulls. 1. Growth and carcass composition. Anim. Prod. 42: 203211.Google Scholar
Galbraith, H. and Topps, J. H. 1981. Effects of hormones on the growth and body composition of animals. Nutr. Abstr. Rev. Ser. B 51: 521540.Google Scholar
Heitzman, R. J. 1976. The effectiveness of anabolic agents in increasing rate of growth in farm animals; report on experiments in cattle. In Environmental Quality and Safety, Suppl. Vol. V. (ed. Coulston, F. and Korte, F.), pp. 8998. George Thieme, Stuttgart.Google Scholar
Jury, K. E., Fourie, P. D. and Kirton, A. H. 1977. Growth and development of sheep. IV. Growth of the musculature. N.Z.Jl agric. Res. 20: 115121.Google Scholar
Meat and Livestock Commission. 1984. UK Weekly Market Survey 84/46.Google Scholar
Tan, G. Y. and Fennessy, P. F. 1981. The effect of castration on some muscles of red deer (Cervus elaphus L). N.Z.Jl agric. Res. 24: 13.CrossRefGoogle Scholar
Truscott, T. G., Wood, J. D. and Macfie, H. J. H. 1983. Fat deposition in Hereford and Friesian steers. I. Body composition and partitioning of fat between depots. J. agric. Sci., Camb. 100: 257270.CrossRefGoogle Scholar
Williams, D. R. and Bergstrom, P. L. 1980. Anatomical jointing, tissue separation and weight recording. EEC standard method for beef. Commission of the European Communities, Brussels. EUR 6878 EN. (Mimeograph).Google Scholar