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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
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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

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