CHRONOLOGICAL LOSS OF BONE ZINC DURING DIETARY ZINC DEPRIVATION IN NEONATAL PIGS

This research was conducted to measure the chronological changes in zi nc concentrations of biopsied bone, hair, and plasma samples collected weekly during dietary zinc deprivation. Pigs 1-2 wk of age were fed a basal diet (< 1 mu g Zn/g) during a l-wk depletion period and then as signed to one of three dietary regimens for 4 wk: a low-zinc diet (4 m u g Zn/g) fed ad libitum, an adequate-zinc diet (100 mu g/g) fed ad li bitum, and an adequate-zinc diet restricted in intake to allow weight gain comparable with that of the low-zinc group. Bone zinc remained at approximate to 120 mu g/g dry wt for the control groups fed adequate zinc but steadily declined in pigs fed the low-zinc diet, leveling off at approximate to 25% of the control values. Plasma and hair zinc con centrations also decreased but at a more rapid rate. Bone zinc is mobi lizable in neonatal pigs, and biopsied bone zinc concentration is a re liable index of zinc status.