饲粮铜添加水平对生长獭兔生长性能、毛皮品质、肌肉品质及氮代谢的影响

Effects of Dietary Copper Supplemental Level on Growth Performance,Fur Quality,Muscle Quality and Nitrogen Metabolism of Growing Rex Rabbits

本试验旨在研究饲粮铜添加水平对生长獭兔生长性能、毛皮品质、肌肉品质及氮代谢的影响。选取200只体况相近的1月龄健康獭兔,随机分为5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、5、15、45、135 mg/kg铜的试验饲粮,试验饲粮中铜含量的实测值分别为8.19、13.59、23.78、54.08、143.68 mg/kg。预试期7 d,正试期60 d。结果表明:饲粮铜添加水平对平均日增重、平均日采食量有极显著影响(P<0.01),对料重比没有显著影响(P>0.05)。当饲粮铜添加水平为15 mg/kg时,平均日增重及平均日采食量均达到最高值。饲粮铜添加水平对毛皮重量有显著影响(P<0.05),对毛皮面积及毛皮厚度没有显著影响(P>0.05)。5 mg/kg组的毛皮重量显著高于45、135 mg/kg组(P<0.05),但与15 mg/kg组差异不显著(P>0.05)。饲粮铜添加水平对肌肉滴水损失有极显著影响(P<0.01),对肌肉p H45 min和黄度值有显著影响(P<0.05),对肌肉剪切力及亮度、红度值均无显著影响(P>0.05)。当饲粮铜添加水平为15 mg/kg时滴水损失有最小值,p H45 min有最大值。饲粮铜添加水平对食入氮、尿氮、沉积氮、氮利用率及氮生物利用率有极显著影响(P<0.01),对粪氮、氮表观消化率有显著影响(P<0.05)。综合本试验测定指标,生长獭兔饲粮适宜的铜添加水平为15 mg/kg(饲粮中铜含量的实测值为23.78 mg/kg)。

This experiment was conducted to investigate the effects of dietary copper supplemental level on growth performance,fur quality,meat quality and nitrogen metabolism of growing Rex rabbits. Two hundred1-month-old Rex rabbits with the similar health conditions were randomly assigned to 5 groups with 40 replicates per group and 1 rabbit per replicate. Rabbits in 5 groups were fed experimental diets with the following copper supplemental levels： 0,5,15,45 and 135 mg / kg,and copper content measured values in experimental diets were 8. 19,13. 59,23. 78,54. 08 and 143. 68 mg / kg,respectively. The trial lasted for 7 days for adaptation and 60 days for test. The results showed as follows： dietary copper supplemental level had extremely significant influences on average daily gain and average daily feed intake（ P〈0. 01）,and had no significant influence on feed / gain（ P〉0. 05）. The highest values of average daily gain and average daily feed intake appeared when dietary copper supplemental level was 15 mg / kg. Dietary copper supplemental level had significant influence on fur weight（ P〈0. 05）,but had no significant influences on fur area and fur thickness（ P〉0. 05）. The fur weight in 5 mg / kg group was significantly higher than that in 45 and 135 mg / kg groups（ P〈0. 05）,but no significant difference was found between 5 and 15 mg / kg groups（ P〉0. 05）. Dietary copper supplemental level had extremely significant influence on drip loss（ P〈0. 01）,and had significant influences on muscle pH45 m inand yellowness（ b＊） value（ P〈0. 05）,but had no significant influences on muscle shear force and the values of lightness（ L＊） and redness（ a＊）（ P〉0. 05）. The minimum of drip loss and the maximum of pH45 m inappeared when dietary copper supplemental level was 15 mg / kg. Dietary copper supplemental level had extremely significant influences on nitrogen intake,urinary nitrogen,digestible nitrogen,nitrogen retention,nitrogen apparent digestibility and nitrogen bioavailability（ P〈0. 01）,and had significant influences on fecal nitrogen and nitrogen availability（ P〈0. 05）. Considering all indices of this experiment,the appropriate dietary copper supplemental level is 15 mg / kg for growing Rex rabbits（ dietary copper content measured value is 23. 78 mg / kg）.