本试验旨在研究饲粮铜添加水平对3~4月龄生长獭兔生长性能、血清生化指标、毛皮质量及氮代谢的影响。选用160只健康、体重相近的3月龄獭兔，随机分为4组（每组40个重复，每个重复1只），分别饲喂在基础饲粮中添加0、30、60、120 mg/kg铜（以五水硫酸铜形式）的试验饲粮。预试期7 d，正试期29 d。结果显示：在初始体重（IBW）无显著差异（P>0.05）的前提下，饲粮铜添加水平对獭兔的平均日增重（ADG）有显著影响（P<0.05），对平均日采食量（ADFI）有极显著影响（P<0.01）。添加60 mg/kg铜组的ADG显著高于未添加铜组和添加120 mg/kg铜组（P<0.05）；添加60和120 mg/kg铜组的ADFI极显著高于未添加铜组和添加30 mg/kg铜组（P<0.01）。饲粮铜添加水平对獭兔血清总蛋白含量有显著影响（P<0.05），对白蛋白含量有极显著影响（P<0.01）。血清中总蛋白和白蛋白含量均随饲粮铜添加水平的升高呈现先升高后降低的趋势，且均以添加30 mg/kg铜组最高。饲粮铜添加水平对獭兔的皮张重量、皮张面积、皮张厚度和被毛长度均无显著影响（P>0.05）。饲粮铜添加水平对食入氮（IN）、尿氮（UN）和氮生物学效价（NBV）均有显著影响（P<0.05）。在铜添加水平为30 mg/kg时，尿氮最低，氮生物学效价最高。综合本试验测定的各项指标得出，3~4月龄生长獭兔饲粮适宜的铜添加水平为30 mg/kg（饲粮中铜含量的实测值为39.1 mg/kg）。

This experiment was conducted to investigate the effects of dietary copper supplemental level on growth performance, serum biochemical indices, fur quality and nitrogen metabolism of 3 to 4-month-old growing Rex rabbits. One hundred and sixty 3-month old healthy Rex Rabbits with similar body weight were randomly assigned to 4 groups with 40 replicates in each group and each replicate contained 1 rabbit. Rabbits in 4 groups were fed experimental diets which supplemented with 0, 30, 60 and 120 mg/kg copper (in the form of copper sulfate pentahydrate) based on a basal diet, respectively. The pre-experimental period lasted for 7 days and the formal test for 29 days. The results showed as followed:under the premise that there was no significant difference in initial body weight (IBW) (P>0.05), dietary copper supplemental level had significant influence on average daily gain (ADG) (P<0.05), and had extremely significant influence on average daily feed intake (ADFI). The ADG in adding 60 mg/kg copper group was significantly higher than that in no adding copper group and adding 120 mg/kg copper group (P<0.05). The ADFI in adding 60 and 120 mg/kg copper groups was extremely significantly higher than that in no adding copper group and adding 30 mg/kg copper group (P<0.01). Dietary copper supplemental level had significant influence on serum total protein content (P<0.05), and had extremely significant influence on serum albumin content (P<0.01). With the dietary copper supplemental level increasing, serum total protein and albumin contents were firstly increased and then decreased, and the highest values of them were all found in adding 30 mg/kg copper group. Dietary copper supplemental level had no significant influences on fur weight, fur thickness, fur area and hair length (P>0.05). Dietary copper supplemental level had extremely significant influences on intake nitrogen (IN), urinary nitrogen (UN) and nitrogen biological value (NBV) (P<0.01). When copper supplemental level was 30 mg/kg, the urinary nitrogen was the lowest and the nitrogen biological value was the highest. Considering all indexes of this experiment, the appropriate dietary copper supplemental level is 30 mg/kg for 3 to 4-month-old growing Rex rabbits (the measured value of diet copper content is 39.1 mg/kg).