Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-18T06:21:29.782Z Has data issue: false hasContentIssue false
  • English
  • Français

A meta-analysis of studies of the effect of GnRH 11-14 days after insemination on pregnancy rates in cattle

Published online by Cambridge University Press:  27 February 2018

A R Peters ,
T Martinez  and
A J C Cook
A R Peters*
Affiliation:
Department of Farm animal and Equine Medicine and Surgery, Royal Veterinary College, Hawkshead Campus, North Mymms, Hatfield, Herts, AL9 7TA, UK
T Martinez
Affiliation:
Department of Farm animal and Equine Medicine and Surgery, Royal Veterinary College, Hawkshead Campus, North Mymms, Hatfield, Herts, AL9 7TA, UK
A J C Cook
Affiliation:
Department of Farm animal and Equine Medicine and Surgery, Royal Veterinary College, Hawkshead Campus, North Mymms, Hatfield, Herts, AL9 7TA, UK
*
1Present address: Pfizer Central Research, Sandwich, Kent, CT13 9NJ, UK
Get access

Abstract

The aim of the study was to conduct a meta-analysis of published data on the effect of GnRH analogues given between 11 and 14 days after first insemination, on pregnancy rates of cattle, to ascertain if a consolidated estimate of treatment response could be determined. The results of 18 studies from 13 published papers were analysed. Odds ratios calculated for each study were found to be heterogeneous, i.e. there was significant variation in treatment response among studies, between 0 and 22% improvement in pregnancy rate. Logistic regression analysis showed that five variables affected the outcome of the model, viz., herd type (beef or dairy), age of animal (cow or heifer), oestrus synchronisation and method and time of pregnancy diagnosis. However when all variables were included only 6/13 of the publications could be analysed (2,541 /10,833 animals).

Type
Posters
Information
BSAP Occasional Publication , Volume 26 , Issue 2: Fertility in the High-Producing Dairy Cow , September 2001 , pp. 457 - 459
Copyright
Copyright © British Society of Animal Science 2001

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

Armitage, P. and Berry, G. 1994. Statistical methods in medical research. Blackwell Science Ltd., Oxford.Google Scholar
Drew, S.B. and Peters, A.R. 1994. Effect of buserelin on pregnancy rates in dairy cows. Veterinary Record 134: 267–269.Google Scholar
Greenland, S. 1994. A critical look at some popular meta-analytic methods. American Journal of Epidemiology 140: 290–296.Google Scholar
Jubb, T.F., Abhayaratne, D., Malmo, J. and Anderson, G.A. 1990. Failure of an intramuscular injection of an analogue of GnRH 11 to 13 days after insemination to increase pregnancy rates in dairy cattle. Australian Veterinary Journal 67: 359–361.CrossRefGoogle ScholarPubMed
Lajili, H., Humblot, P. and Thibier, M. 1991. Effect of PGF2 alpha treatment on conception rates of dairy cows treated with a GnRH agonist 12 to 14 days after artificial insemination. Theriogenology 36: 335–347.CrossRefGoogle ScholarPubMed
LeFever, D.G., Holland, M.D., Greathouse, G.A., Schafet, D.W., Brinks, J.S. and Odde, K.G. 1991. Journal of Animal Science Suppl. 1: 397.Google Scholar
Macmillan, K.L., Taufa, V.K. and Day, A.M. 1986. Effects of an agonist of GnRH (buserelin) in cattle. III. Pregnancy rates after a post-insemination injection during metoestrus or dioestrus. Animal Reproduction Science 11: 1–10.CrossRefGoogle Scholar
Muir, M.R., Stannett, A., Offer, J.E., Ball, P.J.H., Taylor, C. and Logue, D.N. 1998. Oestrus synchronisation combined with buserelin administration in beef cattle. Veterinary Record 143: 143–144.CrossRefGoogle ScholarPubMed
Rettmer, I., Stevenson, J.S. and Corah, L.R. 1992. Pregnancy rates in beef cattle after administering a GnRH agonist 11 to 14 days after insemination. Journal of Animal Science 70: 7–12.Google Scholar
Ryan, D.P., Kopel, E., Boland, M.P. and MacEoin, F. 1988. Effects of Receptal administered at time of service or day 12 of the estrous cycle on pregnancy rates in Holstein cows in Saudi Arabia. 11th International Congress on Animal Reproduction and Artificial Insemination, University College, Dublin, Ireland Vol. 4. paper no. 457.Google Scholar
Ryan, D.P., Snijders, S., Condon, T., Grealy, M., Sreenan., J. and O'Farrell, K.J. 1994. Endocrine and ovarian responses and pregnancy rates in dairy cows following the administration of a gonadotrophin releasing hormone analog at the time of artificial insemination or at mid-cycle post insemination. Animal Reproduction Science 34: 179–191.Google Scholar
Sheldon, I.M. and Dobson, H. 1993. Effects of GnRH administered 11 days after insemination on the pregnancy rates of cattle to die first and later services. Veterinary Record 133: 160–163.Google Scholar
Stata Corp., 1997. Stata statistical software: Release 5.0. College Station, Texas: Stata Corporation.Google Scholar
Stevenson, J.S., Phatak, A.P., Rettmer, I. and Stewart, R.E. 1993. Postinsemination administration of receptal: Follicular dynamics, duration of cycle, hormonal responses, and pregnancy rates. Journal of Dairy Science 76: 2536–2547.CrossRefGoogle ScholarPubMed
Taufa, V.K., Macmillan, K.L., Day, A.M., Ashcroft, M.J. and Morgan, S. 1998. Some effects of using progesterone and gonadotrophin releasing hormone on the reproductive performance of inseminated cows. Proceedings of the New Zealand Society of Animal Production 58: 92–94.Google Scholar
Thatcher, W.W., Drost, FM., Savio, J.D., Macmillan, K.L., Entwistle, K.W., Schmitt, E.J., De la Sota, R.L. and Morris, G.R. 1993. New clinical uses of GnRH and its analogues in cattle. Animal Reproduction Science 33: 27–49.Google Scholar