Comparing the effect of single-dose and double-dose injection of vitamin E-selenium during Late Pregnancy on Production and Reproductive Performance in Holstein cows

The appropriate effects of supplementation with minerals and vitamins on reproductive performance have been well studied before. The object of this study was to determine the effect of prepartum supplementation with vitamin E and selenium on milk yield and reproductive performances in dairy cows. In this study, 247 Holstein dairy cows were selected during prepartum transitional period and divided randomly into two groups. A group: a single injection of vitamin E + selenium at Day 250 of gestation and B group: two injection of vitamin E + selenium at days 250 and 270 of gestation. Indices of reproductive performance, milk yield and milk somatic cell count were compared between two groups. There was no significant difference in reproductive indices in B group compared to A group. Milk yield in different month of after calving and somatic cell count did not show any significant difference between groups. In summary, the results of this study showed that use of extra supplementation with vitamin E and selenium in prepartum period did not significantly affect reproductive parameters, milk yield and the somatic cell count.