Possible involvement of selenium in Staphylococcus aureus inhibition in cow's whey

Previous investigations have shown that selenium supplementation inhibits growth of mastitis pathogens in cow's milk. The present study was performed to clarify the role of selenium in defence mechanisms of mammary gland. We have examined the effects of selenium supplementation on Staphylococcus aureus growth inhibiting activity in whey. Six selenium-supplemented and six non-supplemented Estonian dairy cows were used for this study. Selenium-supplemented cows received 4 mg organic selenium in the form of selenium yeast in their daily diet for 8-week period. Cows from non-supplemented group received the same amount of yeast free of selenium in their diet. All cows had initially low blood glutathione peroxidase (GPx) activity (