EFFECT OF PREPARTUM INJECTION OF VITAMIN-E AND SELENIUM ON POSTPARTUMREPRODUCTIVE FUNCTION OF DAIRY-CATTLE

A total of 198 cows were randomly assigned to treatment with a single intramuscular injection of 10 mi of a preparation containing vitamin E and selenium or placebo 3 wk before expected parturition. Incidence o f retained fetal membranes was 3.0% for the treated group and 10.1% fo r the control group (P=0.06). Administration of MU-SE also increased t he percentage of cows pregnant to the first service (41.2 vs 25.3%; P= 0.02), reduced the number of services per conception (2.3 vs 2.8; P=0. 03), and reduced the interval from calving to conception (121 vs 141 d ays; P=0.06). The effect of MU-SE on fertility was apparent in cows wi th and without retained fetal membranes. There was no effect of MU-SE on the interval from calving to the first estrus. In conclusion, prepa rtum supplementation with vitamin E and selenium can decrease the inci dence of retained fetal membranes, increase pregnancy rates and, there by, reduce the interval from calving to conception in lactating dairy cows.