Factors related to uterine score and its influence on pregnancy per artificial insemination in crossbred dairy cows

This study evaluated the relationships of postpartum uterine disease, parity and body condition score (BCS) to uterine score and their influence on pregnancy per artificial insemination (P/AI) at the first postpartum service of crossbred dairy cows. A total of 588 Holstein x Gir dairy cows from 20 farms were monitored during the first 35 days postpartum to diagnose retained placenta, metritis and clinical endometritis. Cows were subjected to timed AI after the end of the voluntary waiting period. Uterine scores were evaluated at the time of the timed AI, between 35 and 65 days postpartum, and cows were grouped according to uterine size and position: small uterus in the pelvic cavity (SPS1), medium uterus in the transition between the pelvic and abdominal cavities (SPS2) and large uterus within the abdominal cavity (SPS3). The uterine score was related to occurrence of postpartum uterine disease, number of cases, parity, and BCS (P<0.01). P/AI in SPS1 cows (30.03%) tended to be higher (P=0.09) than those in SPS2 and SPS3 cows together (23.67%). In conclusion, postpartum uterine disease occurrence, parity and BCS were thus related to uterine size and position score, and lactating cows with a smaller uterus located in the pelvic cavity tended to have better P/AI at the first postpartum service.