Effects of supplementation of vitamin E and selenium during late gestation on milk somatic cells count and incidence of retained placenta in dairy cows

The somatic cell count (SCC) is widely used to predict the health of cow s mammary gland and the suitability of milk for human consumption. The main aim of this study was to evaluate the effects of additional supplementation of vitamin E and selenium at two intervals during late gestationon SCC and retained placenta (RP) in dairy cows. The 138 multiparous Holstein dairy cows were selected, which were randomly divided into two treatment and control groups. The cows in the control group (n=66) received a single injection of vitamin E and selenium at one dose (20 cc/cow) on day 250 of pregnancy, and in the treatment group (n=72) received two injections of vitamin E and selenium on days 250 and 270 of gestation.The SCC, milk production, RP percentage, and reproductive indices were calculated in all cows.The results showed that the SCC, milk production, RP percentage, and reproductive indices of cows in the treatment group have no significant difference from the control group. However, the calving to the first insemination interval and RP percentage in the treatment group was reduced.According to the results of the present study, it seems that more detailed studies are needed to find the effects of additional supplementation of vitamin E and selenium on the incidence of RP, milk, and SCC.