Survey of copper and zinc concentrations in commercially available dry ferret diets

Abstract

To survey macronutrients and two micronutrients (copper and zinc) in commercial ferret diets to investigate dietary factors that may influence copper-associated hepatopathy in ferrets. Proximate analysis and copper and zinc concentrations of 12 commercially available dry adult maintenance ferret diets. Medians were calculated on a dry matter and metabolizable energy basis and compared to the Association of American Feed Control Officials (AAFCO) nutrient profiles for cats and the National Research Council (NRC) recommendations for mink. Calculated metabolizable energy of diets ranged from 3830 to 4305 kcal/kg dry matter (DM). Crude protein ranged from 89.1 to 151.4 g/1000 kcal, nitrogen-free extract ranged from 13.9 to 124.7 g/1000 kcal, and crude fat ranged from 29.6 to 52.4 g/1000 kcal. The median copper concentration was 9.0 mg/1000 kcal and 37.8mg/kg DM, 7 times the AAFCO minimum for cats and 6.3 times the recommendation for mink. Median zinc concentration was 64.2 mg/1000 kcal and 243.1mg/kg DM, 3.4 times the AAFCO minimum for cats and 3.7 times the NRC recommendation for mink. The median zinc to copper ratio was 6.7. There is considerable variation in micro- and macronutrient composition among tested commercial ferret diets. High copper concentrations in ferret diets may contribute to copper-associated hepatopathy in ferrets.