Effect of single vs multiple ovulations on oestrous behaviour and pregnancy rate in Thoroughbred mares

A relatively high rate of multiple ovulation and resulting multiple pregnancies are one of main problems in Thoroughbred reproduction. The aim of the study was to examine the relationship between the intensity of oestrous behaviour and incidence of multiple (MO) vs single (SO) ovulations in 47 Thoroughbred mares. The frequency of five distinct receptive and 12 non-receptive behavioural traits was analysed. For quantitative analysis of sexual behaviour an 8-point behavioural score (BS) expressing increasing mare’s sexual receptivity was used. MO occurred in 48.9% of ovarian cycles observed. Neither frequencies of receptive behaviours, nor BS differed significantly between MO and SO mares. Overall pregnancy rate per one ovulatory cycle was estimated as 40.4%. Pregnancy rate was higher in MO mares (52.2%) as compared to SO mares (29.2%); however, the difference was not proved significant.

Author A. Gorecka and T. Jezierski
Year 2003
Secondary title Animal Science Papers & Reports
Volume 21
Number 1
Pages 27-33