Maternal-fetal relationships of copper, manganese, and sulfur in ruminants. A review.

Placental transfer and localization of copper, manganese, and sulfur in the ruminant are described. The fetus is completely dependent upon the dam for its supply of these minerals. Numerous studies have shown significant correlations between fetal and maternal tissue copper concentration. Because copper is essential for development of the central nervous system of the embryonic lamb, an acute maternal hypocuprosis can cause gross brain lesions in the fetal or neonate lamb. Manganese deficiency in the gestating ruminant has deleterious effects on the developing embryo; inadequate dietary manganese induces an abnormal development of the epiphysial fetal cartilage. This review provides information on partition of dietary sulfur between maternal tissues, fetus, and placenta. Sulfur may be transferred to the ruminant fetus in a variety of organic forms as well as in the inorganic form.