Toleration of High Concentrations of Dietary Zinc by Mink

Abstract

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.

Toxicological Profile for Zinc

“…Zinc oxide consumption caused anemia in dogs (76.5 mg zinc/kg/day) (Drinker et al 1927d), ferrets (195 mg zinc/kg/day) (Straube et al 1980), and preruminant calves (64 mg zinc/kg/day) (Jenkins and Hidiroglou 1991). Hematological alterations were not observed in cats exposed to up to 83.2 mg zinc/kg/day as zinc oxide (Drinker et al 1927d) or in adult mink exposed to zinc at up to 297.4 mg zinc/kg/day as zinc oxide (Aulerich et al 1991;Bleavins et al 1983) or to rats exposed to 53 mg…”

“…The relevance of this effect to humans is unclear. Body weights of rabbits (Bentley and Grubb 1991), rats , and minks (Aulerich et al 1991) were unaffected by dosing with 174, 191, and 326.7 mg zinc/kg/day, respectively, for 3-12 months. Decreased postpartum body weights in F0 animals were observed in rats exposed to 7 mg zinc/kg/day as zinc chloride for 20 weeks (Khan et al 2001b).…”

“…In dogs (Drinker et al 1927d) and minks (Aulerich et al 1991), histological changes in the pancreas have not been observed at doses comparable to or higher than the dose levels that caused abnormalities in rats, mice, cats, ferrets, and sheep. Degeneration of the acinar cells of the pancreas was observed in sheep by Allen et al (1983) and in rats and mice by Maita et al (1981).…”

“…It is not known if sheep are a good model for human toxicity because they are ruminants. No renal effects were observed in either adult mink consuming 326.7 mg zinc/kg/day as zinc sulfate or in young mink consuming 323.6 mg zinc/kg/day as zinc sulfate for 144 days (Aulerich et al 1991). Minks exposed to 195 mg zinc/kg/day as zinc oxide for 7-97 days in the food developed a diffuse nephrosis, though it did not increase with increasing dose (Straube et al 1980).…”

“…Similarly, no histopathology was observed in rats administered 98.3 mg zinc/kg/day as zinc oxide, but an insufficient number of animals were tested (Drinker et al 1927c (Aulerich et al 1991).…”