2005 Volume 22 Pages 117-120
Effect of changeover from a zinc-sufficient diet to a zinc-deficient diet on feed intake, body weights and tissue zinc contents was examined. Five-week-old male Wistar rats were given zinc-sufficient diets containing 15 ppm of zinc as zinc sulfate or oyster extract for 21 days. Thereafter, rats in each group were divided into 2 groups: one group was given a zinc-deficient diet, while the other group was given a zinc-sufficient diet for a further 7 days. The changeover to a zinc-deficient diet decreased fecal zinc excretion remarkably and lowered feed intake and body weight within 3 to 4 days. Zinc concentrations in various tissues were also decreased by the changeover to a zinc-deficient diet. The extent of the decrease varied with the type of tissue; zinc concentration in tibia was remarkably lowered. Differences in zinc source did not affect tissue zinc concentration. These findings indicate that the adverse effects of a zinc-deficient diet appeared within 3 to 4 days after starting the deficient diet even in zinc-sufficient rats because the amount of stored zinc is small.
