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Response of castrated male sheep to oestrogenic and androgenic compounds implanted alone or in combination

Published online by Cambridge University Press:  02 September 2010

H. Galbraith ,
S. B. Singh  and
J. R. Scaife
H. Galbraith
Affiliation:
Department of Agriculture, University of Aberdeen, 581 King Street, Aberdeen AB24 5UA
S. B. Singh
Affiliation:
Department of Agriculture, University of Aberdeen, 581 King Street, Aberdeen AB24 5UA
J. R. Scaife
Affiliation:
Department of Agriculture, University of Aberdeen, 581 King Street, Aberdeen AB24 5UA
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Abstract

Forty-eight Greyface wether lambs, aged about 6 months and weighing 32 kg on average were used. They were allocated to be treated, by subcutaneous implantation in the upper surface of the ear flap, with the naturally occurring steroids oestradiol-17β (O), testosterone (T) or the synthetically produced androgen trenbolone acetate (TA). Treatment groups were as follows: sham-implanted controls (C); 50 mg O (slow release formulation) (O); 40 mg TA (compressed pellets} (TA); 50 mg T (compressed pellets) (T); 15 mg O + 40 mg TA (TAO); 15 mg O + 50 mg T (TO). Combined implants were placed in close proximity under the skin of the same ear. The lambs were offered, to appetite, a good quality diet containing per kg dry matter (DM) an estimated 12-0 MJ metabolizable energy and 150 g crude protein. Comparisons were made for the main effects of O and the androgens T and TA. Main effects due to O were increased DM intake, live-weight gain (LWG) empty body weight (EBW), chilled carcass iveight (CCW), carcass crude protein (CP) deposition, plasma insulin concentrations and teat length with reductions recorded for the proportion but not weight of fat in the carcass, plasma urea and thyroxine concentrations. Treatment with androgens did not, on average, influence LWG or other indices of growth performance or carcass composition other than to produce significant increases in carcass phosphorus deposition and reduction in the depth of thorax. Significant increases in the iveight of penile tissue and reductions in teat length were recorded. There was evidence for a greater androgenic effect on penile tissue and anti-oestrogenic effect (on teat length) of TA compared with T at the concentrations used. TA also reduced the weight of the thymus gland, an effect reversed in the presence ofO.

Analysis of plasma taken from the vein contralateral to the site of implantation showed that O concentrations were reduced in the presence of TA and T, and that O had no effect on the concentrations of androgens measured. Concentrations ofT and 17 β-hydroxy-trenbolone in blood were of a similar order, which for T is typical of postpubertal entire male sheep.

The results suggest that O treatment was effective in promoting growth and carcass CP deposition which was not increased by T or TA, despite the presence of these androgens at biologically active concentrations in blood. This effect appears to differ from the additive effects frequently obtained for castrated male cattle.

Keywords

androgenscarcass compositiongrowthoestrogenswethers
Type
Research Article
Information
Animal Science , Volume 64 , Issue 2 , April 1997 , pp. 261 - 269
Copyright
Copyright © British Society of Animal Science 1997

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References

Donaldson, I. A., Hart, I. C. and Heitzman, R. J. 1981. Growth hormone, insulin, prolactin and total thyroxine in the plasma of sheep implanted with the anabolic steroid trenbolone acetate alone or with oestradiol. Research in Veterinary Science 30: 713.CrossRefGoogle ScholarPubMed
Galbraith, H. 1982. Growth, hormonal and metabolic response of post pubertal entire male cattle to trenbolone acetate and hexoestrol. Animal Production 35: 269–276.Google Scholar
Galbraith, H. and Berry, A. D. 1994. Effect of naturally occurring and synthetic androgens on growth, body composition and muscle glucocorticoid receptors in wether lambs. Animal Production 58: 357–364.Google Scholar
Galbraith, H., Hatendi, P. R., Alderson, E. M. and Scaife, J. R. 1990. The effect of cimaterol and oestradiol-17β alone or combined on growth and body composition of wether lambs. Animal Production 51: 311–319.Google Scholar
Galbraith, H., Kennedy, D. J. and Henderson, G. F. 1986. Growth, body composition and muscle glucocorticoid receptors in lambs implanted with oestradiol-17β alone or combined with testosterone or progesterone. Journal of Animal Science 63: (suppl. 1) 233 (abstr.).Google Scholar
Galbraith, H. and Topps, J. H. 1981. Effect of hormones on the growth and body composition of animals. Nutrition Abstracts and Reviews, series B. 51: 521–550.Google Scholar
Hancock, D. L., Wagner, J. F. and Anderson, D. C. 1991. Effects of estrogens and androgens on animal growth. In Growth regulation in farm animals (ed. Paterson, A. M. and Dutson, T. R.), pp. 255–298. Elsevier Applied Science, London.Google Scholar
Heitzman, R. J., Gibbons, D. N., Little, W. and Harrison, L. P. 1981. A note on the comparative performance of beef steers implanted with the anabolic steroids trenbolone acetate and oestradiol-17β alone or in combination. Animal Production 32: 219–222.Google Scholar
Lawes Agricultural Trust. 1977. Genstat V, mark 4.01. Rothamsted Experimental Station, Harpenden, UK.Google Scholar
Lough, D. S., Kahl, S., Solomon, M. B. and Rumsey, T. S. 1993. The effect of trenbolone acetate on performance, plasma lipids and carcass characteristics of growing ram and ewe lambs. Journal of Animal Science 71: 2659–2665.Google Scholar
MacRae, J. C., Bruce, L. A., Hovell, F. D. DeB., Hart, I. C., Inkster, J., Walker, A. and Atkinson, T. 1991. Influence of protein nutrition on the response of growing lambs to exogenous bovine growth hormone. Journal of Endocrinology 130: 53–61.Google Scholar
MacVinish, L. J. and Galbraith, H. 1988. The effect of implantation of trenbolone acetate and oestradiol-17β in wether lambs at two initial live weights on concentrations of steroidal residues and blood glucose, urea and thyroid hormones. Animal Production 47: 75–85.Google Scholar
MacVinish, L. J. and Galbraith, H. 1993. A note on the concentrations of steroidal residues in tissues of mature female sheep implanted with trenbolone acetate. Animal Production 56: 277–280.Google Scholar
Quirke, J. F. and Sheehan, W. 1981. Effect of anabolic steroids on the performance of hill and lowland lambs. Irish Journal of Agricultural Research 20:125–135.Google Scholar
Sharpe, P. M., Buttery, P. J. and Haynes, N. B. 1986. The effect of manipulating growth in sheep by diet or anabolic agents on plasma cortisol and muscle glococorticoid receptors. British Journal of Nutrition 56: 289–304.CrossRefGoogle ScholarPubMed
Sinclair, L. A., Galbraith, H. and Scaife, J. R. 1991. Effect of dietary protein concentration and cimaterol on growth and body composition of entire male lambs. Animal Feed Science and Technology 34:181–192.CrossRefGoogle Scholar
Sinnett-Smith, P. A., Dumelow, N. W. and Buttery, P. J. 1983. Effects of trenbolone acetate and zeranol on protein metabolism in male castrate and female lambs. British Journal of Nutrition 50: 225–234.Google Scholar
Sulieman, A. H., Galbraith, H. and Topps, J. H. 1986. Growth performance and body composition of early weaned wether lambs treated with trenbolone acetate combined with oestradiol-17β. Animal Production 43: 109–114.Google Scholar
Sulieman, A. H., Galbraith, H. and Topps, J. H. 1988. Growth performance and body composition of wether lambs implanted at two different initial live weights with trenbolone acetate combined with oestradiol-17β. Animal Production 47: 65–74.Google Scholar
Sulieman, A. H., Galbraith, H. and Topps, J. H. 1992. Growth performance and body composition of mature female sheep implanted with trenbolone acetate. Animal Production 54: 53–58.Google Scholar
Yasin, A. R. M. and Galbraith, H. 1981. A note on the response of wether lambs to treatment with trenbolone acetate combined with oestradiol-17β or zeranol. Animal Production 32: 337–340.Google Scholar