Effects of selenium and vitamin E on blood selenium levels, tissue glutathione peroxidase activities and white muscle disease in sheep fed purified or hay diets

The effects of selenium and vitamin E on blood selenium levels and tissue glutathione peroxidase activities were determined in sheep fed purified and hay diets. A significant increase of blood levels of this element and tissue glutathione peroxidase activities was found in sheep given selenium as compared to those not receiving this element. Of the tissues examined, the highest glutathione peroxidase activity was found in the heart. Vitamin E had no influence on either the blood selenium levels or upon the tissue glutathione peroxidase activity. With hydrogen peroxide as the substrate, tissue glutathione peroxidase activity was not correlated with the incidence of white muscle disease. Evidence is presented to suggest that 0.1 ppm dietary selenium is not sufficient under some conditions to meet the physiological requirements for this element.