Cholistani İneklerde Boğa Maruziyetinin Doğum-sonrası Üreme Etkinliği Üzerine Etkisi

The present study was conducted with the objective to determine the effect of bull exposure on postpartum resumption of ovarian activity, first behavioural oestrus and conception rate in Cholistani cows. A total of 24 Cholistani cows kept at Shadabad Cooperative Livestock Farms Cholistan, Pakistan during September-2012 to January-2013, were divided into two groups. Bull exposed (BE) cows (n=18) were exposed to mature bull throughout the study period whereas bull not exposed (BNE) cows (n=6) were not. Both groups were kept under similar feeding and management conditions. The mean interval from the calving to resumption of ovarian activity was 39.75±3.19 days in the BE and 49.75±2.75 days in BNE animals (P<0.05). The mean interval from the calving to the first behavioural oestrus was 46.93±0.48 days in BE and 57.5±1.29 days in BNE animals (P<0.05). During the study period, more (P<0.05) cows from the BE group (16/18 = 88.88%) showed behavioural oestrus as compared to the BNE group ones (4/6=66.66%). The conception rate in BE and BNE cows were 66.66% and 33.33%, respectively (P<0.05). It was concluded that, cows exposed to the presence of bulls at early postpartum periods showed reduced intervals from the calving to resumption of ovarian activity, first behavioural oestrus and resumed cyclicity earlier.