Effects of dietary protein levels and implanted melatonin on growth performance, serum biochemical parameters and nutrient digestibility of minks (Mustela vison)

Abstract

Ninety healthy male mink at the age of fifty-day-old with a similar body weight(P>0.05) were randomly allotted to six groups, each of which was replicated fifteen times with one mink per replicate. A 3×2(CP×MT) completely random experiment was designed. The minks in 3 groups (1, 2 and 3) which were injected melatonin capsules (10 mg each) on 15 July 2010 were fed experimental diets with protein levels of 32% (CP1), 36% (CP2) and 40% (CP3), respectively, while those in control groups (4 to 6), which were not injected with melatonin were fed the same diets with trial groups. The feeding trial lasted for 64 days. The results showed as follows: (1) For growing minks, injecting melatonin 10 mg merly increased the body weight and average daily gain which were the highest group fed with CP1 level. The body weight of MT groups fed with CP1level was significantly higher than that of controlled group (P<0.05). The body weight and average daily gain were not significantly affected by the interaction of the protein levels and exogenous melatonin. (2) The serum ALB concentration of MT treatment groups was significantly lower than that of controlled fed with CP1 and CP3 levels (P<0.01). For treatment and controlled minks, the serum TG concentration of CP1 and CP2 levels were significantly higher than those of CP3 level (P<0.05). (3) For MT group, the fat digestibility of CP2 level was higher siginificantly than that of CP1 and CP3 level (P<0.05). The interaction between protein levels and implanted MT had no influence on the protein, fat digestibility (P>0.05).