Effect of Zinc Deficiency during Lactation on Postnatal Growth and Development of Rats

Abstract

The effect of dietary zinc deficiency on the lactating female rat and on the postnatal development of the suckling young was investigated. Female Sprague-Dawley rats were fed either a zinc-supplemented (100 ppm zinc) or a zinc-deficient (0.4 ppm zinc) purified diet throughout lactation. Inanition controls received the zinc-supplemented diet in amounts restricted to the mean daily food intake of the deficient animals. Zinc deficiency during lactation rapidly reduced maternal blood plasma zinc concentration and caused an impairment in milk production which was specifically due to the lack of zinc rather than to inanition. In addition, the milk produced was lower in zinc content than that of either ad libitum or restricted-fed controls. As a consequence, pups suckling zinc-deficient lactating females received half the amount of zinc that the control pups received on the basis of body weight. Thus they became zinc-deficient with reduced plasma zinc concentration, symptoms of zinc deficiency, impaired growth, and increased mortality.