Postpartum anoestrus in Holstein x Lai Sind crossbred dairy cows in small farms of Ho Chi Minh City

The aim of the study was to assess the prevalence of postpartum (PP) anestrus and the effect of factors on this prevalence in small dairy farmers. The data of 419 calvings and PP periods from 35 small dairy farms was collected during two years 2013 and 2014. Cows which failed to express estrus signs by day 60th after calving were submitted for manual palpation and transrectal ultrasonography to evaluate ovarian state.
49.9% of observed cows were not detected in estrus by the stockman during the first 60 days PP. The prevalence of type I, type II, cystic, pyometral and detective anestrus (or subestrus) was 27.0, 6.7, 0.5, 0.7 and 15.0%, respectively. The presence of dystocia or uterine infection was accompanied by an increase in risk of the type I anestrus (36.7% vs 23.1%, P = 0.005; 41.4% vs 21.5% , P < 0.001, respectively). Cows with a low BCS at calving (< 3) or at the 30th day PP (< 2.5) significantly showed a high risk of the type I anestrus than cows with a medium or high BCS at the same periods. In conclusion, the anestrus type I and subestrus mainly contriduted to high risk of PP anestrus in small dairy farms in HCMC. The dystocia, uterine infection, low BCS at calving and at day 30th PP constituted major causes of the type I anestrus.