本试验旨在研究饲粮铜水平对育成期蓝狐生长性能、营养物质消化率及氮代谢的影响。试验选择健康55日龄蓝狐100只,随机分成5组,每组20个重复(公母占1/2),每个重复1只。Ⅰ~Ⅴ组蓝狐分别饲喂铜含量为7.89、20.00、40.00、80.00、160.00 mg/kg的试验饲粮。预试期7 d,正试期60 d。结果表明:1)Ⅲ组公狐的平均日增重显著高于Ⅴ组(P<0.05),料重比显著低于Ⅴ组(P<0.05);Ⅲ组母狐的平均日增重显著高于Ⅰ组(P<0.05),料重比显著低于Ⅰ组(P<0.05)。2)Ⅲ组公狐的干物质消化率、蛋白质消化率极显著高于Ⅱ、Ⅴ组(P<0.01),显著高于Ⅳ组(P<0.05),Ⅲ组公狐的脂肪消化率极显著高于其他4组(P<0.01),其他各组间差异不显著(P>0.05);各组母狐之间干物质消化率、蛋白质消化率均无显著差异(P>0.05),Ⅰ组母狐的脂肪消化率极显著低于Ⅲ组(P<0.01),显著低于Ⅳ、Ⅴ组(P<0.05)。3)Ⅲ组公狐的氮沉积、净蛋白质利用率极显著高于Ⅴ组(P<0.01),Ⅰ、Ⅱ、Ⅲ组公狐的蛋白质生物学价值极显著高于Ⅴ组(P<0.01);Ⅲ组母狐的氮沉积、净蛋白质利用率和蛋白质生物学价值显著高于Ⅱ组(P<0.05),其他各组间差异不显著(P>0.05)。由此可见,当饲粮铜水平为40.00 mg/kg时,饲粮营养物质消化率、氮沉积、净蛋白质利用率、蛋白质生物学价值较为理想,且可获得较佳的生长性能。

This experiment was conducted to study the effects of dietary copper level on growth performance, nutrient digestibility and nitrogen metabolism of growing blue foxes. One hundred healthy blue foxes at the age of 55 days were randomly assigned into 5 groups with 20 replicates (10 males and 10 females) per group and 1 fox per replicate. The foxes in the 5 groups (groups Ⅰ to Ⅴ) were fed experimental diets contained 7.89, 20.00, 40.00, 80.00 and 160.00 mg/kg copper, respectively. The adaptation period lasted for 7 days and the formal period lasted for 60 days. The results showed as follows: 1) the average daily gain in male group Ⅲ was significantly higher than that in male group Ⅴ (P<0.05), while the feed to gain in male group Ⅲ was significantly lower than that in male group Ⅴ (P<0.05). The average daily gain in female group Ⅲ was significantly higher than that in female group Ⅰ (P<0.05), while the feed to gain in female group Ⅲ was significantly lower than that in group Ⅰ (P<0.05). 2) The dry matter (DM) digestibility and the protein digestibility in male group Ⅲ were significantly higher than those in male groups Ⅱ and Ⅴ (P<0.01), and significantly higher than those in group Ⅳ (P<0.05). The fat digestibility of male group Ⅲ was significantly higher than that in other male groups (P<0.01), and there was no significant difference among other groups in fat digestibility (P>0.05). There were no significant differences among female groups in DM and protein digestibility (P>0.05). The fat digestibility in female group Ⅰ was significantly lower than that in female group Ⅲ (P<0.01), and significantly lower than that in female groups Ⅳ and Ⅴ (P<0.05). 3) The nitrogen deposition and the net protein utilization in male group Ⅲ were significantly higher than those in male group Ⅴ (P<0.01). The biological value of protein in male group Ⅴ were significantly lower than that in male groups Ⅰ, Ⅱ and Ⅲ (P<0.01). The nitrogen deposition, net protein utilization and the biological value of protein in female group Ⅲ were significantly higher than those in female group Ⅱ (P>0.05), and there were no significant differences among other female groups (P>0.05). In conclusion, the nutrient digestibility, nitrogen deposition, net protein utilization, and biological value of protein are ideal when the dietary copper level is 40 mg/kg, and the blue foxes can also get the optimal growth performance.