Toleration of high concentrations of dietary zinc by mink

Adult and kit male and female natural dark ranch mink (Mustela vison) were fed a conventional diet supplemented with 0, 500, 1,000, or 1,500 ppm zinc, as ZnSO4.7H2O, for 144 days. No marked adverse effects were observed in feed consumption, body weight gains, hematologic parameters, fur quality, or survival. Zinc concentrations in liver, kidney, and pancreas of the mink increased in direct proportion to the zinc content of the diet. Histopathologic examination of the livers, kidneys, and pancreata revealed no lesions indicative of zinc toxicosis. The results indicate that mink can tolerate at least 1,500 ppm dietary zinc, as ZnSO4.7H2O, for several months without apparent adverse effects.