The incidence rate, risk factors and impact of retained placenta on the reproductive and productive performance of crossbred dairy cows was evaluated. The frequency distribution of retained placenta and also a Poisson multivariate analysis were developed for the following variables: year, calving season, lactation order, body condition score, gestation length, type of delivery, number and sex of calves. First calf heifers and multiparous cows, with and without retained placenta, during the rainy and dry season, had their average results compared in the following items: days from calving to first service, number of semen doses per conception, milk production up to 305 days and lactation peak. The incidence rate of retained placenta was 12.8%. The risk factors were: rainy calving season, 2nd, 3rd and above 4th lactation orders, body scores below 3.5 and greater than 4.0, abortion, stillbirth, premature birth, assisted birth and multiple birth. An increase of 51.2 and 27.5 days in the average interval between calving and first service, and of 1.2 and 0.6 in the average number of semen doses was observed in multiparous cows with retained placenta, giving birth during the rainy and dry seasons, respectively (P<0.05).
dairy cattle; calving to first service; milk production
