Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-29T00:37:30.386Z Has data issue: false hasContentIssue false
  • English
  • Français

The effect of oestrogenic agents on live-weight gain, carcass composition, reproductive function and tissue residues in intensively reared beef bulls given cereal-based diets

Published online by Cambridge University Press:  02 September 2010

A. R. Peters ,
J. R. Southgate ,
E. Aughey  and
S. N. Dixon
A. R. Peters
Affiliation:
British Technology Group, 101 Newington Causeway, London SE1 6BU
J. R. Southgate
Affiliation:
Meat and Livestock Commission, PO Box 44, Queensway House, Bletchley, Milton Keynes MK2 2EF
E. Aughey
Affiliation:
University of Glasgow, Department of Veterinary Anatomy, Bearsden Road, Bearsden, Glasgow G61 10QH
S. N. Dixon
Affiliation:
Food and Veterinary Laboratory Ltd, 25-26 Frederick Sanger Road, Surrey University Park, Guildford GU2 5YD
Get access

Abstract

The use of oestradiol-17β was evaluated in cereal-based beef production on 14 farms with 450 bulls. Half of the bulls were implanted subcutaneously in the ear with a silastic rubber implant containing 45 mg oestradiol-17β Representative bulls close to mean weight for each group were selected for slaughter on the same day at the end of the trial for carcass measurements. The remaining bulls were slaughtered at the farmers' discretion. Where possible, slaughter live weight (208 bulls), carcass weight (412) and European Economic Community carcass classification (353) were recorded. Implanted bulls had higher gains only in the first 3 months (+76 (s.e. 17) g/day; P < 0·001) and had heavier carcasses with the extra weight in the forequarter (+2·3 (s.e. 0·61) kg; P < 0·001), better carcass shape (+0·9 (s.e. 0·3) points; P < 0·01) and more subcutaneous fat in the thin flank (+1·3 (s.e. 0·6) g/kg; P < 0·05). Implanted bulls selected for slaughter by farmers were not slaughtered earlier, but killed out better (+0·7 (s.e. 0·3) g/kg; P < 0·05) and had heavier carcasses (+4·6 (s.e. 0·5) kg; P < 0·01) of better shape (+0·8 (s.e. 0·3) points; P < 0·05).

The use of zeranol was evaluated in cereal beef production on 15 farms with 385 bulls. Half received 36 mg zeranol which was repeated after 6 months. Forty-four bulls were selected for detailed carcass assessment as above. Implanted bulls had daily gains 0·06 (s.e. 0·01) kg greater (P < 0·001) than controls. Farmers chose to slaughter implanted bulls 8·3 (s.e. 3·8) days earlier (P < 0·05) at only marginally heavier weights (+4·8 (s.e. 3·1) kg; P = 0·08). More implanted bull carcasses were distributed in better shape and higher fat classes (P < 0·01). There were no significant differences in fore- and hindquarter and thin-flank tissue proportions. Oestradiol treatment marginally decreased testis weight in slaughtered bulls whereas zeranol treatment had no significant effect although epididymal weight was decreased in zeranol treated bulls. There were no clear effects of either treatment on testicular structure, but both oestradiol and zeranol caused a degree of disruption to the epididymal epithelium. Zeranol concentrations in treated animal tissues were not significantly different from those in control animals.

Type
Research Article
Information
Animal Production , Volume 47 , Issue 2 , October 1988 , pp. 215 - 221
Copyright
Copyright © British Society of Animal Science 1988

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Acha, P. N. 1933. Foreword. In Anabolics in Animal Production (ed. Meissonier, E. and Mitchell-Vigneron, J.), p. V. Office International dcs Epizooties, Paris.Google Scholar
Buttery, P. J. and Sinnett-smith, P. A. 1984. The mode of action of anabolic agents with special reference to their effects on protein mctabolism — some speculations. In Manipulation of Growth in farm Animals (ed. Roche, J. F. and Callaghan, D. O.) pp. 211–228. Martinus Nijoff, The Hague.CrossRefGoogle Scholar
Deschamps, J. C., Ott, R. S., McEntee, K., Heath, E. H., Heinrchs, R. R., Shanks, R. D. and Hixon, J. E. 1987a. Effects of zeranol on reproduction in beef bulls: scrotal circumference, serving ability, semen characterists, and pathologic changes of the reproductive organs. American Journal of Veterinary Research 48: 137–147.Google Scholar
Deschamps, J. C., Ott, R. S., Weston, P. G., Shanks, R. D., Kesler, D. J., Bolt, D. J. and Hixon, J. E., 1987b. Effects of zeranol on reproduction in beef bulls: lutcinizing hormone, follicle-stimulating hormone, and testosterone secretion in response to gonadotrophin releasing hormone and human chorionic gonadotrophin. American Journal of veterinary Research 48: 31–36.Google Scholar
Dixon, S. N., and Heitzman, R. J., 1983. Measurement of the synthetic anabolic agents agents in the tissues of farm animals. In Anabolics in Animal Production (ed. Meissonier, E. and Mitchell-Vigneron, J.), pp. 381–391. Office International des Epizooties, Paris.Google Scholar
Dixon, S. N. and Russell, K. L. 1986. Radioimmunoassay of the anabolic agent zeranol. IV. The determination of zeranol concentrations in the edible tissues of cattle implanted with zeranol (Ralgro) Journal of Veterinary Pharmacology and Therapeutics 9: 84–100.Google ScholarPubMed
Fossland, R. G. and Schultze, A. B. 1961. A histological study of the postnatal development of the bovine testis. Research Bulletin, Nebraska Agricultural Experiment Station, No. 199.Google Scholar
Glencross, R. G., Abeywardene, S. A., Cornet, S. J. and Morris, H. S. 1981. The use of oestradiol-17β antiserum covalently completed to sepharose to extract oestradiol-17β from biological fluids. Journal of Chromatography 223: 193–197.CrossRefGoogle Scholar
Gray, D. G., Unruh, J. A., Dikeman, M. E. and Stevenson, J. S. 1986. Implanting young bulls with zeranol from birth to four slaughter ages. III. Growth performance and endocrine aspects. Journal of Animal Science 63: 747–756.CrossRefGoogle ScholarPubMed
Haynes, N. B., Hars, H. D., Waters, R. J., Manns, J. G. and Riley, A. 1974. Stimulatory effect of prostaglandin F2(v on the plasma concentration of testosterone in bulls. Journal of Endocrinology 66: 329–338.CrossRefGoogle Scholar
Juniewicz, P. E., Welsh, T. H. and JOHNSON, B. H., 1985. Effects of zeranol upon bovine testicular functiorl. Theriogenology 23: 565–582.CrossRefGoogle Scholar
Kroes, R., Bbrkvens, J. M. and Loendersloot, H. J. 1971. Oestrogen-induced changes in the genital tract of the male calf. Zentralblatt fur Veterinarmedizin Reihe A 18: 717–730.CrossRefGoogle ScholarPubMed
Lamming, G. E. 1957. The use of hormones in meat production. Agricultural Progress 32: 31–38.Google Scholar
Lamming, G. E., Ballarini, G., Baulieu, E. E., Brookes, P., Elias, P. S., Ferrando, R., Galli, C. L., Heitzman, R. J., Hoffman, B., Karg, H., Meyer, H. H. D., Michel, G., Poulsen, E., Rico, A., Leecwen, F. X. R. van and White, D. S. 1987. Scientific report on anabolic agents in animal production. Veterinary Record 121: 389–392.Google Scholar
McEntee, K. 1974. Adenomiosi-dell epididimo bovine e canino. Nuova Veterinaria 50: 194.Google Scholar
O'lamhna, M. and Roche, J. F. 1984. Recent studies with anabolic agents in steers and bulls. In Manipulation of Growth in Farm Animals (ed. Roche, J. F. and O'Callaghan, D.), pp. 85–99. Martinus Nijhoff, The Hague.CrossRefGoogle Scholar
Peters, A. R., Pimentel, M. G. and Lamming, G. E. 1985. Hormone responses to exogenous GnRH pulses in post-partum dairy cows. Journal of Reproduction and Fertility 75: 557–565.CrossRefGoogle ScholarPubMed
Roche, J. F. and Quirke, J. F. 1986. The effects of steroid hormones and xenobiotics on growth of farm animals. In Control and Manipulation of Animal Growth (ed. Buttery, P. J., Haynes, N. B. and Lindsay, D. B.), pp. 39–51. Butterworths, London.CrossRefGoogle Scholar
Silcox, R. W., Keeton, J. T. and Johnson, B. H. 1986. Effects of zeranol and trenbolone acetate on testis function, live weight gain and carcass traits of bulls. Journal of Animal Science 63: 358–368.CrossRefGoogle ScholarPubMed
Van der Wal, P. and Berende, P. L. M. 1983. Effects of anabolic agents on food-producing animals. In Anabolics in Animal Production (ed. Meissonier, E. and Mitchell-Vigneron, J.), pp. 73–115. Office International des Epizooties, Paris.Google Scholar