[Effect of beta-carotin serum concentration on the reproductive performance in dairy cows]

The aim of the following investigation was to study the effect of beta-carotin serum concentrations on reproductive performance in dairy cows. Blood samples were collected from 201 cows 3 to 4 weeks antepartum, 1 to 2 weeks postpartum and at the time of insemination. Concentrations of beta-carotin in blood serum were determined via HPLC. The incidence of retained placental fetal membranes, endometritis, ovarian cysts as well as the beginning of the oestrous cycle and various measures of fertility such as first service conception rate, pregnancy index, interval from calving to first insemination, interval from calving to conception, interval from first insemination to conception and expected calving interval were recorded and analysed. The beta-carotin serum concentrations were not related to the incidence of retained placental fetal membranes, endometritis, ovarian cysts or the onset of cyclicity post partum. Cows with lower beta-carotin concentrations partially seemed to have a reduced reproductive performance than cows with higher beta-carotin concentrations. Overall, our results suggest only a minor relationship between the beta-carotin serum concentration and fertility in dairy cows.