本试验旨在研究饲粮铜、锌添加水平对育成期蓝狐生长性能、营养物质利用率及氮代谢的影响。试验采用2×3完全随机试验设计，分别在基础饲粮中添加2个水平的锌（40和120 mg/kg）和3个水平的铜（30、45和60 mg/kg），另设对照组（添加0 mg/kg铜和40 mg/kg锌）。选用（55±5）日龄、体重相近的健康雄性蓝狐84只，随机分成7组，每组12个重复，每个重复1只。预试期为7 d，正试期为75 d。结果表明：1）饲粮中添加铜有提高蓝狐平均日增重（P=0.06）和降低料重比（P=0.08）的趋势，但并未观测到铜、锌之间的互作效应（P>0.05）。30 mg/kg铜+40 mg/kg锌和45 mg/kg铜+120 mg/kg锌组平均日增重显著高于对照组（P<0.05），料重比显著低于对照组（P<0.05）。2）饲粮中添加铜能极显著提高蓝狐蛋白质和脂肪消化率（P<0.01）。60 mg/kg铜+40 mg/kg锌和60 mg/kg铜+120 mg/kg锌组蓝狐蛋白质消化率极显著高于对照组（P<0.01），45 mg/kg铜+120 mg/kg锌组显著高于对照组（P<0.05）。30 mg/kg铜+40 mg/kg锌、45 mg/kg铜+40 mg/kg锌、30 mg/kg铜+120 mg/kg锌、60 mg/kg铜+120 mg/kg锌组蓝狐脂肪消化率极显著高于对照组（P<0.01），45 mg/kg铜+120 mg/kg锌组显著高于对照组（P<0.05）。饲粮铜、锌添加水平对粪便中铜排出量有极显著影响（P<0.01）；饲粮锌添加水平对粪便中锌排出量有极显著影响（P<0.01）。各组蓝狐铜排出量和锌排出量并未观测到铜、锌之间的互作效应（P>0.05）。3）饲粮中添加铜极显著降低了粪氮含量（P<0.01），饲粮铜、锌添加水平并未对各组蓝狐食入氮、尿氮、氮沉积含量及蛋白质生物学价值、净蛋白质利用率产生显著影响（P>0.05）。综合试验结果得出，育成期蓝狐饲粮中添加30 mg/kg铜+40 mg/kg锌（总铜、总锌水平为别37.68和80.08 mg/kg）时可提高蓝狐的生长性能和营养物质消化率，同时降低了粪便中氮的排放。

This experiment was conducted to study the effects of dietary copper (Cu) and zinc (Zn) supplemental level on growth performance, nutrient digestibility and nitrogen metabolism of growing blue foxes. The experiment used a 2×3 completely randomized experimental design. Experimental diets were supplemented with 2 Zn levels (40 and 120 mg/kg) and 3 Cu levels (30, 45 and 60 mg/kg), respectively. The control group's diet was supplemented with 0 mg/kg Cu and 40 mg/kg Zn. Eighty four healthy male blue foxes at the age of (55±5) days were randomly assigned into 7 groups with 12 replicates per group and 1 fox per replicate.The pre-trial period lasted for 7 days and the trial period lasted for 75 days. The results showed as follows: 1) dietary supplemented with Cu was tended to improve the average daily gain (ADG) (P=0.06) and reduce the ratio of feed to gain (F/G) (P=0.08) of blue foxes, however, there was no interaction in ADG and F/G between Cu and Zn (P>0.05). The ADG in 30 mg/kg Cu+40 mg/kg Zn and 45 mg/kg Cu+120 mg/kg Zn groups was significantly higher than that in control group (P<0.05), but the F/G was significantly lower than that in control group (P<0.05). 2) Dietary supplemented with Cu significantly increased the digestibility of protein and fat (P<0.01). The protein digestibility in 60 mg/kg Cu+40 mg/kg Zn, 60 mg/kg Cu+120 mg/kg Zn and 45 mg/kg Cu+120 mg/kg Zn groups was significantly higher than that in control group (P<0.05 or P<0.01). The fat digestibility in 30 mg/kg Cu+40 mg/kg Zn, 45 mg/kg Cu+40 mg/kg Zn, 30 mg/kg Cu+120 mg/kg Zn, 60 mg/kg Cu+120 mg/kg Zn and 45 mg/kg Cu+120 mg/kg Zn groups was significantly higher than that in control group (P<0.05 or P<0.01). Dietary Cu and Zn supplemental level significantly affected the Cu output in faeces (P<0.01), dietary Zn supplemental level significantly affected the Zn output in faeces (P<0.01). There was no interaction in Cu output and Zn output between Cu and Zn (P>0.05). 3) Dietary supplemented with Cu significantly decreased the fecal nitrogen content (P<0.01). Dietary Cu and Zn supplemental levels had no significant effects on nitrogen intake, urine nitrogen, nitrogen retention, net protein utilization and biological value of protein (P>0.05). In conclusion, dietary supplemented with 30 mg/kg Cu+40 mg/kg Zn (total Cu and total Zn levels were 37.68 and 80.08 mg/kg, respectively) can improve the growth performance and nutrient digestibility of growing blue fox. Meanwhile, it also can reduce the nitrogen excretion in faeces.