The importance of selenium availability and deficiency in cattle - the prevention of deficiency

In many districts of Germany a deficiency of selenium and vitamin E elicite d disturbances of cattle, such as muscular dystrophy, retained placenta, ma stitis, reduced growth and reproduction rates and immunosuppression, result in sub-optimal productivity. Selenium deficiency is most prevalent in graz ing animals, when no minimal feed containing selenium is provided. Selenium is essential for the synthesis of four different types of glutathione pero xidase and of other selenium-containing proteins. In the cow the improvemen t of the supply of selenium is of special importance in the perinatal perio d. This can be rectified by the parenteral administration of 50 mg selenium and 3,000 mg vitamin E on the 21(st) and 5(th) days before calving. This h as a favourable effect on the vitality of the new born calf. The potential improvements in the supply of selenium are described. In addition to the pa renteral administration and the use of boluses, the supply of a mineral sup plement containing a concentration of selenium of 50 mg/kg and of 30,000 IU vitamin E/kg is recommended.