The requirement of net protein (NP) and metabolizable protein (MP) by Dorper crossbred ewe lambs grown from 35 to 50 kg of body weight (BW) was assessed by comparative slaughter experiment. Thirty-five ewe lambs (33.5 ± 0.6 kg BW) of F1 crosses of Dorper × thin-tailed Han sheep were used: 7 lambs were slaughtered as reference animals at the start of the trial, and the remaining 28 lambs were randomly divided into 4 groups of 7 lambs each. Three of the 4 groups were fed a pelleted mixed diet (concentrate/roughage = 44:56, dry matter basis) for ad libitum intake or 65% or 45% of ad libitum intake, and they were all slaughtered when the lambs that were fed ad libitum reached 50 kg BW. The lambs from the fourth group were also fed ad libitum and slaughtered at 43 kg BW as the intermediate group. The intake of MP by the animals of these 4 groups was estimated, and their total body protein and protein retention were measured. The daily requirements of NP and MP for maintenance were 1.52 and 3.98 g/kg BW0.75 , respectively, with a partial efficiency of MP utilization for maintenance of 0.38. The MP requirement for growth ranged from 77.4 to 124.5 g/day for average daily gains from 100 to 250 g BW, and the partial efficiency of MP utilization for growth was 0.66. The Dorper crossbred ewe lambs required more MP for both maintenance and growth in comparison with the recommendations of the US nutritional system.

中文翻译：

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Dorper×稀尾汉杂交母羊羔对可代谢蛋白质的需求。

通过比较屠宰实验评估了生长在35至50公斤体重（BW）的Dorper杂交母羊羔对净蛋白质（NP）和可代谢蛋白质（MP）的需求。使用Dorper×细尾寒羊F1杂交的35只母羊羔羊（33.5±0.6 kg BW）：在试验开始时将7只羔羊作为参考动物屠宰，其余28只羔羊随机分为4只每组7只羊羔。4组中的3组以粒状混合饮食（浓缩液/粗饲料= 44:56，以干物质为基础）喂养，随意摄入或随意摄入65％或45％，当喂养羔羊时将它们全部宰杀随意达到体重50公斤体重。第四组的羔羊也被随意喂食，中间体重为43 kg BW。估计这四组动物对MP的摄取，并测量其总体内蛋白质和蛋白质保留。NP养护的每日需求量分别为1.52和3.98 g / kg BW0.75，MP养护利用的部分效率为0.38。MP的生长需求量为77.4至124.5 g /天，平均日增重为100至250 g BW，MP利用生长的部分效率为0.66。与美国营养体系的建议相比，Dorper杂交母羊羔需要更多的MP来维持和生长。38. MP的生长需求量为77.4至124.5 g /天，平均日增重为100至250 g BW，MP利用生长的部分效率为0.66。与美国营养体系的建议相比，Dorper杂交母羊羔需要更多的MP来维持和生长。38. MP的生长需求量为77.4至124.5 g /天，平均日增重为100至250 g BW，MP利用生长的部分效率为0.66。与美国营养体系的建议相比，Dorper杂交母羊羔需要更多的MP来维持和生长。