Effects of zinc sources and levels on zinc bioavailability, blood parameters, and nutrient balance of male mink (Neovison vison)

Abstract

The objective of this study was to investigate the effects of different sources and levels of zinc (Zn) on nutrient digestibility, plasma metabolites, and relative Zn bioavailability in male mink. Animals in the control group were fed a basal diet, consisting mainly of corn, soybean oil, meat and bone meal, and fish meal, with no Zn supplementation. Mink in the other 9 treatments were fed the basal diet supplemented with Zn from grade Zn sulfate (ZnSO₄^.7H₂O), Zn glycinate (ZnGly), or Zn pectin oligosaccharides (ZnPOS) chelate at concentrations of either 100, 300, or 900 mg Zn/kg dry matter. The results showed that zinc levels increased the AD of fat linearly (P < 0.05). The AD of fat in Zn-900 was higher (P < 0.05) than that of the control. Fecal Zn and urinary Zn were affected by dietary Zn addition (P < 0.01). Moreover, Zn supplementation increased Zn retention compared with the control group (P < 0.05). The N retention in ZnPOS was higher (P < 0.05) than that of the control. The effect of Zn level was linear (P < 0.01) for N retention. In addition, the activity of alkaline phosphatase was higher in groups supplemented with 900 mg/kg Zn (P < 0.05) compared with the control group. There were significant interactions (P < 0.05) among Zn sources on the activity of Cu-Zn superoxide dismutase (Cu-ZnSOD). Compared with ZnSO₄, relative bioavailability values were 148% and 173% for ZnGly and ZnPOS, respectively, based on Cu-ZnSOD activity. In conclusion, our data show that the relative bioavailability of ZnPOS was greater than that of ZnSO₄^.7H₂O and ZnGly and Zn supplementation can enhance the Cu-ZnSOD of male mink, and mink can efficiently utilize ZnGly and ZnPOS.