The aim of this work was to evaluate the effect of selenium and vitamin E on incidence of mastitis in Holstein cows. Eighty cows were allocated into four treatments: control, supplementation with 2.5 mg Se day-1, supplementation with 1,000 UI vitamin E day-1 , and supplementation with 2.5 mg Se day-1 + 1,000 UI vitamin E day-1 . The supplementation started 30 days prior to probable parturition date until parturition. Forage and concentrate samples were taken every 15 days for chemical and selenium analyses. Blood samples were taken before starting supplementation, right after parturition, 30 and 60 days after it to determine the selenium serum levels. Tamis test and udder analysis were weekly performed to detect clinical mastitis. Selenium supplemented cows had higher serum selenium concentration compared with control group (P<0.05). Vitamin E and selenium did not decrease the prevalence of clinical mastitis up to 12th week and there was no interaction between those elements.
antioxidant; prepartum; milk quality; oral supplementation
