Duration of the breeding season on the reproductive performance of Anglo-Nubian goats during dry and rainy periods

Abstract

The study was aimed to evaluate the effect of breeding season (BS) duration on goat reproduction during dry (DS) and rainy (RS) periods. Females were kept 300 m apart from bucks for 60 days. Females were randomly distributed among BS groups of 25 (BS25), 35 (BS35), and 45 (BS45) days during DS and RS. All females cycled, except during BS45 in DS (95%). The duration of BS did not affect estrous incidence during DS and RS. The percentage of females with two estrous was similar in RS (BS25: 30%, BS35: 35%, BS45: 35%) and DS (BS25: 25%, BS35: 30%, BS45: 25%). Three estrous were observed in BS35 and BS45 during RS (5%). First estrous (FE) and second estrous (SE) were detected from days in BS25 (FE: 1-21, SE: 7-21), BS35 (FE: 1-23, SE: 6-27), and BS45 (FE:1-23, SE: 9-20) during RS. During DS, estrous were detected within days BS25 (FE: 1-17, SE: 6-23), BS35 (FE: 1-20, SE: 6-24), and BS45 (FE: 2-21, SE: 6-21). Pregnancy rates were similar in RS (BS25: 90%, BS35: 95%, BS45: 95%) and DS (BS25: 75%, BS35: 80%, BS45: 75%). In conclusion, goat BS can be shorten despite weather without any effect on reproduction.