Response of sexually inactive French Alpine bucks to the stimulus of goats in oestrus

Abstract

This study was designed to investigate whether sexually inactive French Alpine bucks stimulated with goats in oestrus are able to induce oestrus and ovulation in anoestrus goats under intensive conditions at latitude 26° N. Fifty-nine adult anoestrus French Alpine goats were randomly assigned to one of four treatment groups: exposure to stimulated (n=14) or non-stimulated (n=15) bucks in March and stimulated (n=15) or non-stimulated (n=15) bucks in June. Additionally, the sexual behaviour exhibited by bucks in contact with penned goats was recorded during two consecutive observation sessions lasting 1h each. The oestrus response was 79 and 100% for goats exposed to stimulated bucks in March and June, respectively, but none of the goats exposed to the non-stimulated bucks entered oestrus in either breeding seasons. Pregnancy rates based on ultrasonographic examination at 50d post-copulation were lower (P<0.01) in goats exposed to stimulated bucks in March (50%) compared to goats bred in June (80%). For both breeding seasons, none of the goats exposed to non-stimulated bucks kidded. The interval to oestrus was shorter (68±2 vs. 141±13h) and more synchronised in goats exposed to stimulated bucks in June than goats exposed to bucks in March. The frequencies of flehmen, nosing, and approaches were higher (P<0.01) in simulated bucks than non-stimulated bucks. It was concluded that the exposure of sexually inactive bucks to goats in oestrus is an inexpensive, practical and efficient way to elicit sexual activity in bucks, which subsequently triggers breeding activity of anoestrus French Alpine goats.