本试验旨在研究杜泊羊生长期蛋白质需要量。采用2×3析因设计,因素为性别(公、母)和饲粮粗蛋白质水平,通过饲养试验和代谢试验研究其对生长期杜泊羊生产性能和氮平衡的影响。结果表明,3个饲粮粗蛋白质水平之间杜泊羊的平均日增重差异显著(P<0.05),高粗蛋白质组最高,为222.31 g/d,其次为中粗蛋白质组,为186.57 g/d,低粗蛋白质组最小,为121.43 g/d;每增重l g公羊粗蛋白质需要量为0.44 g,母羊为0.42 g。生长期杜泊羊粗蛋白质和可消化粗蛋白质需要量的估测模型分别为:公羊,RCP=3.87W^0.75+0.44△W (R²=0.981),RDCP=2.48W^0.75+0.28△W (R²=0.979);母羊,RCP=3.86W^0.75+0.42△W (R²=0.977),RDCP=2.46W^0.75+0.28△W (R²=0.962) 。

This study was conducted to investigate the protein requirement for growing Dorper sheep. A 2×3 factorial design were used, and the factors were sex (ram and ewe) and dietary crude protein (CP) levels. The effects on performance and nitrogen balance of Dorper sheep were investigated in feeding and metabolism tests. The results showed that there was significant difference in average daily gain (ADG) of Dorper sheep under the three dietary CP levels (P<0.05), and the ADG in high CP group (222.31 g/d) was the highest, followed with that in middle CP group (186.57 g), and the lowest was that in low CP group (121.43 g); the requirement of 1 g weight gain for rams was 0.44 g, and that for ewes was 0.42 g. The formulas of requirement of CP and digestible CP of growing Dorper sheep were as follows: ram, RCP=3.87W^0.75+0.44△W (R²=0.981), RDCP=2.48W^0.75+0.28△W (R²=0.979); ewe: RCP=3.86W^0.75+0.42△W (R²=0.977), RDCP=2.46W^0.75+0.28△W (R²=0.962).