为研究饲粮脂肪水平对育成期银狐生长性能、营养物质消化率及氮代谢的影响，选取12周龄左右、体重相近的健康雄性银狐50只，随机分成5组（每组10个重复，每个重复1只），分别饲喂添加8%（Ⅰ组）、10%（Ⅱ组）、12%（Ⅲ组）、14%（Ⅳ组）和16%（Ⅴ组）混合油脂（鸡油：豆油=1：1）的试验饲粮，试验饲粮对应的脂肪水平为9.9%、11.7%、13.3%、15.6%、17.4%。预试期为20 d，正试期为55 d。结果表明：1）饲粮脂肪水平对育成期银狐平均日增重、干物质采食量、日采食代谢能和料重比均无显著影响（P>0.05）。2）饲粮脂肪水平极显著影响育成期银狐脂肪和碳水化合物消化率（P<0.01），显著影响总能消化率（P<0.05），而对蛋白质和干物质消化率无显著影响（P>0.05）。随饲粮脂肪水平的升高，脂肪和总能消化率提高，碳水化合物消化率降低。其中，Ⅴ组较Ⅰ组脂肪和总能消化率分别提高了11.48%（P<0.01）和4.98%（P<0.05），而碳水化合物消化率则降低了12.41%（P<0.01）。3）饲粮脂肪水平对育成期银狐食入氮和粪氮无显著影响（P>0.05），而极显著影响尿氮、氮沉积、净蛋白质利用率和蛋白质生物学价值（P<0.01）。其中，尿氮以Ⅴ组最高，Ⅰ组最低，组间差异极显著（P<0.01）；氮沉积、净蛋白质利用率和蛋白质生物学价值以Ⅰ组最高，Ⅴ组最低，组间差异极显著（P<0.01）。综合各项指标，从降低环境污染和饲料成本以及保证银狐生长性能的角度出发，育成期银狐饲粮中以添加8%的混合油脂使饲粮脂肪水平达到9.9%为宜。

This experiment was conducted to study the effects of dietary fat level on growth performance, nutrient digestibility and nitrogen metabolism of silver foxes in growing period. Fifty male silver foxes aged about 12 weeks with similar body weight were randomly divided into 5 groups with 10 replicates per group and 1 fox per replicate, they were fed experimental diets supplemented with 8% (group Ⅰ), 10% (group Ⅱ), 12% (group Ⅲ), 14% (group Ⅳ) and 16% (group Ⅴ) mixed oil (chicken oil：soybean oil=1：1), and the corresponding dietary fat levels were 9.9%, 11.7%, 13.3%, 15.6% and 17.4%, respectively. The adaptation period lasted for 20 days and the formal period lasted for 55 days. The results showed as follows: 1) dietary fat level had no significant effects on the average daily gain, dry matter intake, daily metabolizable energy intake and feed/gain (P>0.05). 2) Dietary fat level had a significant effect on the digestibility of fat (P<0.01), gross energy (P<0.05) and carbohydrate (P<0.01), but had no significant effect on the digestibility of dry matter and protein (P>0.05). The digestibility of fat and gross energy was increased with dietary fat level increasing, while the digestibility of carbohydrate was declined. Compared with group Ⅴ, the digestibility of fat and gross energy in group Ⅰ was increased by 11.48% (P<0.01) and 4.98% (P<0.05), respectively, while the digestibility of carbohydrate was decreased by 12.41% (P<0.01). 3) Dietary fat level had no significant effects on nitrogen intake and fecal nitrogen (P>0.05), but had significant effects on urea nitrogen, nitrogen retention, net protein utilization and biological value of protein (P<0.01). The urea nitrogen in group Ⅴ was the highest and that in group Ⅰ was the lowest, and a significant difference was found between groups Ⅴ and Ⅰ (P<0.01); the nitrogen retention, net protein utilization and biological value of protein in group Ⅰ were the highest and those in group Ⅴ were the lowest, and significant differences were found between groups Ⅰ and Ⅴ (P<0.01). Considering all indices, the 8% is considered to be an optimal supplemental level of mixed oil in the diet (dietary fat level is 9.9%) for silver foxes in terms of reducing feed expenses and environmental pollution, and maintaining growth performance.