Effects of stillbirth and dystocia on subsequent reproductive performance in Japanese Black cattle.

The objective of this study was to determine the effects of stillbirth and dystocia on subsequent reproductive performance in Japanese Black cattle. Data were collected for 34,763 calvings from 13,186 animals on 826 farms. Stillbirth was associated with a decreased first service conception rate compared to cows with a normal calving (44.4 versus 54.0%, respectively, P < 0.001). Cows with a normal calving required fewer artificial inseminations per conception and had a lower stillbirth rate at subsequent parity than those with stillbirth and dystocia (P < 0.001). Japanese Black cows with stillbirth and dystocia had inferior subsequent reproductive performance compared with those with a normal calving.