This experiment was conducted to study the effects of dietary protein level and Lys/Met on growth performance and gastrointestinal morphology of early-weaner Tibetan lambs. A total of 98 early-weaner Tibetan lambs aged (55 ±2) days with the body weight of (10.85 ±0.65) kg were randomly allocated into 7 groups with 14 lambs (7 males and 7 females) in each group. Three dietary protein levels (21. 03% , 18. 02% and 15.01% ) were set, and Lys/Met of 18.02% and 15.01% protein diets was adjusted to 2.6, 3.1 and 3.6, respectively. The experiment lasted for 20 days. The results showed as follows; 1) with the increase of dietary protein level, feed intake and average daily gain were increased, diarrhea rate was decreased, the gain of rumen and other complex stomachs was increased, small intestine was lengthened, and rumen papillae and intestinal villus were developed better. 2) Under dietary protein levels of 18. 02% and 15. 01% , the optimal Lys/ Met was 3.1. 3) The diet containing 18. 02% protein (Lys/Met =3.1) could substitute the diet containing high protein level (21.03% ), and the diet containing 15.01% protein (Lys/Met = 3.1) could substitute the diet containing meddle protein level (18.02% ). The results indicate that a favorable dietary protein level and Lys/Met can improve growth and development of gastrointestinal tract, and the optimal Lys/Met can decrease dietary protein requirement.%本试验旨在研究饲粮蛋白质水平及赖氨酸/蛋氨酸(Lys/Met)对早期断奶藏羔羊生长性能及胃肠道组织形态的影响.试验选取(55±2)日龄、平均体重(l0.85±0.65) kg断奶藏羔羊98只,随机分为7组,每组14只,公母各占1/2.设3个饲粮蛋白质水平(21.03％、18.02％和15.01％),调整蛋白质水平为18.02％和15.01％的饲粮的Lys/Met分别为2.6、3.1和3.6.试验期20 d.结果表明:1)随饲粮蛋白质水平的增加,藏羔羊采食量和平均日增重增加,腹泻率降低,藏羔羊瘤胃等复胃增重,小肠增长,瘤胃乳头和小肠绒毛发育得到优化；2)藏羔羊早期断奶饲粮在18.02％及15.01％蛋白质水平下,以Lys/Met为3.1的配比效果为最佳；3)蛋白质水平为18.02％(Lys/Met =3.1)的饲粮可替代21.03％的高蛋白质饲粮,蛋白质水平为15.01％(Lys/Met=3.1)的饲粮可替代18.02％的中蛋白质饲粮.结果提示,适宜的饲粮蛋白质水平及Lys/Met能够促进早期断奶藏羔羊胃肠道良好的生长发育,合理的Lys/Met能够降低其对蛋白质的需要量.
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