本试验旨在研究饲粮添加不同水平黄芪多糖对冬毛期北极狐生产性能、氮代谢及肠道形态结构的影响。试验选取40只157日龄、平均体重为（5 613±46）g的健康雄性北极狐，随机分成4组，每组10个重复，每个重复1只。各组分别饲喂在基础饲粮中添加0（对照组）、100（Ⅰ组）、200（Ⅱ组）和300 mg/kg（Ⅲ组）黄芪多糖的试验饲粮。预试期7 d，正试期40 d。结果表明：1）Ⅰ组和Ⅲ组的平均日增重显著高于对照组（P<0.05）。Ⅰ组和Ⅲ组的料重比极显著低于对照组（P<0.01），Ⅱ组显著低于对照组（P<0.05）。Ⅰ组的体长显著高于对照组（P<0.05）。各组之间平均干物质采食量和鲜皮长无显著差异（P>0.05）。2）Ⅰ组和Ⅱ组的净蛋白质利用率极显著高于对照组和Ⅲ组（P<0.01），Ⅰ组和Ⅱ组的蛋白质生物学价值显著高于对照组和Ⅲ组（P<0.05）。各组之间氮采食量、粪氮排出量、尿氮排出量和氮沉积均无显著差异（P>0.05）。3）Ⅰ组、Ⅱ组和Ⅲ组的绒毛高度极显著高于对照组（P<0.01）。Ⅰ组和Ⅱ组的隐窝深度极显著低于对照组和Ⅲ组（P<0.01）。Ⅰ组和Ⅱ组的绒毛高度/隐窝深度极显著高于对照组和Ⅲ组（P<0.01），Ⅲ组显著高于对照组（P<0.05）。由此可见，饲粮添加100 mg/kg黄芪多糖能够增加冬毛期北极狐对蛋白质的利用效率，改善其肠道形态结构，提高生产性能。

This experiment was conducted to study the effects of different dietary Astragalus polysaccharide (APS) supplemental levels on performance, nitrogen metabolism and intestinal morphology of Arctic foxes during the winter fur-growing period. Forty healthy 157-day-old male Arctic foxes with average body weight of (5 613±46) g were randomly divided into 4 groups with 10 replicates per group and 1 fox per replicate. Foxes in each group were fed basal diets supplemented with 0 (control group), 100 (group Ⅰ), 200 (group Ⅱ) and 300 mg/kg (group Ⅲ) APS, respectively. The experiment was 7 days for adaption and 40 days for trial period. The results showed as follows:1) the average daily gain of groups Ⅰ and Ⅲ was significantly higher than that of the control group (P<0.05). The ratio of feed to gain of groups Ⅰ and Ⅲ was significantly lower than that of the control group (P<0.01), and that of group Ⅱ was significantly lower than that of the control group (P<0.05). The body length of group Ⅰ was significantly higher than that of the control group (P<0.05). No significant differences were found in average dry matter intake and fresh fur length among all groups (P>0.05). 2) The net protein utilization of groups Ⅰ and Ⅱ was significantly higher than that of the control group and group Ⅲ (P<0.01), the biological value of protein of groups Ⅰ and Ⅱ was significantly higher than that of the control group and group Ⅲ (P<0.05). No significant differences were found in nitrogen intake, fecal nitrogen output, urine nitrogen output and nitrogen retention among all groups (P>0.05). 3) The villous height of groups Ⅰ, Ⅱ and Ⅲ was significantly higher than that of the control group (P<0.01). The crypt depth of groups Ⅰ and Ⅱ was significantly lower than that of the control group and group Ⅲ (P<0.01). The villous height/crypt depth of groups Ⅰ and Ⅱ was significantly higher than that of the control group and group Ⅲ (P<0.01), and that of group Ⅲ was significantly higher than that of the control group (P>0.05). In conclusion, diet added 100 mg/kg APS can increase the protein utilization efficiency, improve the intestinal morphology, enhance performance of Arctic foxes during the winter fur-growing period.