The importance of selenium in the prenatal and postnatal development of calves and lambs.

Selenium deficiency is responsible for Zenker type muscle degeneration in calves, lambs, and foals in the prenatal and postnatal stages of development. Investigations have shown that the selenium GSH Px, and vitamin E content of the maternal and fetal parts of the placenta in cattle are different. Similarly, low concentrations of selenium are present in milk from cows and sheep. In addition to an inadequate supply of selenium and vitamin E as a contributory cause of fetal nutritive muscular dystrophy (FNMD), it is assumed that a placental transport block and/or impaired selenium metabolism in the placenta are also responsible. Postnatal nutritive muscular dystrophy, however, is attributed to either acute selenium and vitamin E deficiency in basic feed or impaired plant absorption of selenium as a result of antagonistic elements, such as sulphur.