本试验旨在研究饲粮铜水平对冬毛期银狐铜表观生物学利用率及组织器官铜沉积量的影响。选择50只120日龄、平均体重为(5 134±540)g的健康雌性银狐,随机分成5组,每组设10个重复,每个重复1只银狐。各组分别饲喂在基础饲粮中添加6(Ⅰ组)、30(Ⅱ组)、60(Ⅲ组)、90(Ⅳ组)和150 mg/kg(Ⅴ组)柠檬酸铜的试验饲粮,基础饲粮中铜含量为4.92 mg/kg。预试期7 d,正试期51 d。结果表明:1)饲粮铜水平对平均日采食量、粪排出量和铜表观生物学利用率均无显著影响(P>0.05),对铜摄入量和粪铜排出量有极显著影响(P<0.01)。随着饲粮铜水平增加,铜摄入量和粪铜排出量极显著升高(P<0.01)。2)饲粮铜水平对毛铜、肝铜、肾铜和心铜沉积量均有极显著影响(P<0.01)。随着饲粮铜水平增加,毛铜沉积量呈升高趋势,Ⅴ组沉积量最高;各组间肝铜、肾铜和心铜沉积量未显现出规律性变化。3)饲粮铜水平对心脏重有显著影响(P<0.05),从Ⅱ组至Ⅴ组,心脏重呈降低趋势。饲粮铜水平对肝脏重、肾脏重和脾脏重无显著影响(P>0.05)。综合分析各项试验指标,得出银狐冬毛期基础饲粮中添加60 mg/kg柠檬酸铜(饲粮中铜含量约65 mg/kg)时,有利于银狐对铜的消化利用。

This experment was conducted to study the effects of dietary copper level on copper apparent biological utilization and copper deposition in tissue and organ of silver foxes during the winter hair period. Fifty 120-day-old female silver foxes with an average body weight of (5 134±540) g were selected and randomly assigned into 5 groups with 10 replicates in each group and 1 silver fox in each replicate. Foxes in the 6 groups were fed the basal diets supplemented 6 (group Ⅰ), 30 (group Ⅱ), 60 (group Ⅲ), 90 (group Ⅳ) and 150 mg/kg (group Ⅴ) citric acid copper, respectively. The copper content in basal diet was 4.92 mg/kg. The pre-trial period lasted for 7 days and the trial period lasted for 51 days. The results showed as follows: 1) dietary copper level did not significantly affect average daily feed intake, fecal output and copper apparent biological utilization (P>0.05), but significantly affected the copper intake and fecal copper output (P<0.01). The copper intake and fecal copper output were significantly increased with dietary copper level increasing (P<0.01). 2) Dietary copper level significantly affected the copper deposition in hair, liver, kidney and heart (P<0.01). The hair copper deposition were increased with dietary copper level increasing, and that of group Ⅴ was the highest. There was no regular change on copper deposition in liver, kidney and heart. 3) Dietary copper level significantly affected the heart weight (P<0.05), from group Ⅱ to group Ⅴ, heart weight had a declined trend. Dietary copper level did not significantly affect liver weight, kidney weight and spleen weight (P>0.05). It is concluded that adding 60 mg/kg citric acid copper (actual dietary copper content appropriately 65 mg/kg) in the basal diet is beneficial for digestion and utilization of copper of silver foxesx during the winter hair period.