Effects of dietary copper on nutrient digestibility, tissular copper deposition and fur quality of growing-furring mink (Mustela vison).

The present study investigated the effects of dietary copper (Cu) on growth performance and fur quality in growing-furring minks. One hundred and five standard dark female minks were randomly assigned to seven groups with the following dietary treatments: basal diet with no supplemental Cu (control) and basal diet supplemented with either 6, 12, 24, 48, 96 or 192 mg/kg Cu from copper sulphate, respectively. Our data showed that final body weight (P = 0.033), daily gain (P = 0.029) and fat digestibility (P = 0.0006) responded to increasing levels of Cu. The activity of glutamic-oxalacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) in serum increased (linear and quadratic, P < 0.05) as Cu increased in the diet. Increasing Cu improved total protein (TP) and albumin (ALB) (quadratic, P < 0.05). The level of ceruloplasmin (CER) responded in a linear (P < 0.0001) and quadratic (P < 0.0001) form with increasing level of Cu. Colour intensity of those minks pelted suggested that relatively high levels of supplemental Cu have a beneficial effect on intensifying hair colour of dark mink but did not affect leather thickness. Liver Cu and plasma Cu concentrations of the mink linearly (P < 0.0001) responded to increasing levels of Cu. Our results indicate that growing-furring mink can efficiently utilize added dietary fat and that Cu plays an important role in the digestion of dietary fat in growing-furring mink, and supplemental dietary Cu in growing-furring mink promotes fat digestion and improve hair colour.