Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-22T19:51:14.507Z Has data issue: false hasContentIssue false

The effect of GnRH agonist (buserelin) treatment on day 12 post mating on the reproductive performance of ewes

Published online by Cambridge University Press:  25 May 2016

N. F. G. Beck
Affiliation:
Department of Agricultural Sciences, University of Wales, Aberystwyth SY23 3DD
A. R. Peters
Affiliation:
Hoechst UK Ltd, Walton Manor, Milton Keynes MK7 7AJ
S. P. Williams
Affiliation:
Department of Agricultural Sciences, University of Wales, Aberystwyth SY23 3DD
Get access

Abstract

An investigation was conducted to determine the effects of treatment with the GnRH agonist buserelin on day 12 post mating on the reproductive performance of ewes. There was a non-significant (P > 0·05) increase in nonreturn rate (control 0·76 v. buserelin 0·83) and litter size (control 1·51 v. buserelin 1·77) in three flocks. However, there was a significant (P < 0·05) increase in the number of twin lambs born (control 20 v. buserelin 40) and litter size (control 1·44 v. buserelin 1·68) in the yearling flock. There was no effect of buserelin on oestrous cycle length, although there was a tendency for treated animals to have a longer gestation length and heavier lambs. In a ewe lamb flock there was no effect of buserelin on non-return rate or litter size assessed post slaughter on day 31 of pregnancy. However, ovulation rate tended to be greater in the treated animals, which suggests that buserelin may have induced the formation of accessory corpora lutea. These results indicate that buserelin treatment improves embryo survival and that this effect is particularly evident in yearling ewes.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1994

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

Ashworth, C. J., Sales, D. I. and Wilmut, I. 1989. Evidence of an association between the survival of embryos and periovulatory plasma progesterone concentration in the ewe. Journal of Reproduction and Fertility 87: 2332.Google Scholar
Bolet, G. 1986. Timing and extent of embryonic mortality in pigs, sheep and goats: genetic variability. In Embryonic mortality in farm animals (ed. Sreenan, J. M. and Diskin, M. G.), pp. 1343. Martinus Nijhoff, The Hague.Google Scholar
Davies, M. C. G. and Beck, N. F. G. 1992. Plasma hormone profiles and fertility in ewe lambs given progestagen supplementation after mating. Theriogenology 38: 513526.Google Scholar
Davis, I. F., Kerton, D. J., Parr, R. A., White, M. B. and Williams, A. H. 1986. Hormone supplementation to increase fertility after uterine artificial insemination in ewes. Proceedings of the Australian Society of Animal Production 16: 171173.Google Scholar
Diskin, M. G. and Niswender, G. D. 1989. Effect of progesterone supplementation on pregnancy and embryo survival in ewes. Journal of Animal Science 6: 15591563.CrossRefGoogle Scholar
Flint, A. P. F., Parkinson, T. J., Stewart, H. J., Vallet, J. L. and Lamming, G. E. 1991. Molecular biology of trophoblast interferons and studies of their effects in vivo. Journal of Reproduction and Fertility 43: suppl., pp. 1325.Google Scholar
Kittok, R. J., Stellflug, J. N. and Lowery, S. R. 1983. Enhanced progesterone and pregnancy rate after gonadotropin administration in lactating ewes. Journal of Animal Science 56: 652655.Google Scholar
MacMillan, K. L., Day, A. M., Taufa, V. K., Gibb, M. and Pearce, M. G. 1985. Effects of an agonist of gonadotrophin releasing hormone (buserelin) in cattle. 1. Hormone concentrations and oestrous cycle length. Animal Reproduction Science 8: 203212.Google Scholar
MacMillan, K. L., Taufa, V. K. and Day, A. M. 1986. Effects of an agonist of gonadotrophin releasing hormone (buserelin) in cattle. 3. Pregnancy rates after a post-insemination injection during metoestrus and dioestrus. Animal Reproduction Science 11: 110.Google Scholar
McMillan, W. H., Knight, T. W. and MacMillan, K. L. 1986. Effects of gonadotrophin releasing hormone (buserelin) on sheep fertility. Proceedings of the New Zealand Society of Animal Production 46: 161163.Google Scholar
McMillan, W. H. 1987. Post-mating progesterone supplementation in ewes and hoggets. Proceedings of the New Zealand Society of Animal Production 47: 151153.Google Scholar
Mann, G. E. and Lamming, G. E. 1992. Steroid hormone manipulation in the control of luteolysis in cattle. Journal of Reproduction and Fertility Abstracts Series 9: 32 (abstr.).Google Scholar
Peters, A. R., Drew, S. B., Mann, G. E., Lamming, G. E. and Beck, N. F. G. 1992. Experimental and practical approaches to the establishment and maintenance of pregnancy. Journal of Physiology and Pharmacology 43: suppl. 1, pp. 143152.Google Scholar
Quirke, J. F., Adams, T. E. and Hanarahan, J. P. 1983. Artificial induction of puberty in ewe lambs. In Sheep production (ed. Haresign, W.), pp. 409429. Butterworths, London.Google Scholar
Smith, J. F., Farquhar, P. A. and Welch, R. A. S. 1985. Failure of progesterone administered mid cycle to influence conception rates and embryonic mortality. Proceedings of the Endocrinology Society of Australia 28: suppl., p. 9 (abstr.).Google Scholar
Wilmut, I., Sales, D. I. and Ashworth, C. J. 1986. Maternal and embryonic factors associated with prenatal loss in mammals. Journal of Reproduction and Fertility 76: 851864.CrossRefGoogle ScholarPubMed