Effect of zinc deficiency on the pregnant ewe and developing foetus.

Mature Merino ewes were given either a low-zinc diet (4 mg/kg) or an adequate-Zn diet (50 mg/kg) for all or part of pregnancy. The ewes consuming the low-Zn diet consumed 25% less feed than those given the adequate-Zn diet during the last 115 d of pregnancy. Zn concentration in the plasma of Zn-deficient pregnant ewes declined from 0.7 to 0.3 mg/l. The lambs born to Zn-deficient ewes weighed less and had reduced concentrations of Zn or less total Zn, or both, in the whole carcass, liver and pancreas. A reduction in activity of alkaline phosphatase (EC 3.1.3.1) in the liver and a slight reduction in thymidine kinase (EC 2.7.1.21) activity in the thymus was also observed in Zn-deficient lambs. The Zn-deficient ewes deposited approximately 63 mg Zn into each single-born lamb; this indicates that during the last third of pregnancy the developing foetuses were accumulating the equivalent of 35% of the total dietary Zn intake of the ewes.