中文摘要：

试验选择4头体况良好且安装有永久性瘤胃瘘管和十二指肠瘘管的徐淮白山羊，采用4x3不完全拉丁方设计，配制蛋白水平相同但牧草蛋白来源不同的4组日粮，分别为A（苜蓿、羊草和稻草）、B（羊草和苜蓿）、C（羊草）、D（苜蓿和稻草），旨在研究不同蛋白组成日粮对山羊胃肠道氨基酸和肽的影响。结果表明，D组日粮蛋白质消化率和蛋白质沉积量最高。各处理组瘤胃内游离氨基酸、肽氨基酸浓度分别为25．58、26．64、26．03、26．86mg／100mL和22．82、24．25、23．53、25．73mg／100mL；十二指肠食糜中游离氨基酸、肽氨基酸浓度分剐为32_52、33．52、33．37、33．93mg／100mL和22-39、23．53、23．02、24．21mg／100mL。瘤胃液和十二指肠中游离氨基酸和肽氨基酸浓度的日变化趋势，均是在采食2h后降低，4h后达到峰值。从蛋白质的消化率和进入十二指肠的氨基酸组成来看，苜蓿和稻草组合的D组瘤胃降解率最高，饲喂山羊效果最好。

英文摘要：

The experiment was conducted to study the effects of different protein composition on the concentration of amino acids and peptides of gastrointestinal of goats. Four Xuhuai White goats equipped with ruminal cannulae and duo- denal cannulae were used in this experiment,which designed as a 4-3 Latin square,four diets with similar protein level and different protein sources were formulated as A （alfafa hay, leymus chinensis and straw）, B （alfafa hay and leymus chi- nensis）, C （leymus chinensis ）and D （alfafa hay and straw）. The results showed that：the apparent digestibility of nitrogen and retained nitrogen were the highest in group D. The concentration of free amino acid （FAA） and peptide amino acid （PAA） were 25.58,26.64,26.03,26.86 mg/100 mL and 22.82,24.25,23.53,25.73 mg/100 mL, respectively, in the rumen. The concentration of FAA and PAA in duodenum were 32.52,33.52,33.37,33.93 mg/100 mL and 22.39,23.53,23.02,24.21 rag/100 mL,respeetively,Both the FAA and PAA were decreased at 2 h and highest at 4 h after the morning feeding. Based on the digestibility of protein and AA flowed into the duodenal,the results indicated that group D was the highest for rnminal digestibility and the best feeding effeet of Xuhuai White goat.