摘要
选择6头体重500～600kg ,安装有瘤胃、十二指肠前端和回肠末端瘘管的阉牛 ,分3期饲喂以玉米、棉籽饼和氨化稻草为基础原料配合的3种不同饲养水平的日粮 ,测定十二指肠、回肠和粪便中的粗蛋白质和各种必需氨基酸流量 ,计算粗蛋白质、真蛋白、总必需氨基酸、总非必需氨基酸和各种必需氨基酸在小肠内的表观消化率。结果显示 :随着饲养水平的下降 ,粗蛋白质、真蛋白、总必需氨基酸、总非必需氨基酸和亮氨酸、蛋氨酸、色氨酸、缬氨酸、胱氨酸的小肠表观消化率逐渐降低(P<0.05)。在每种饲养水平下 ,真蛋白的小肠表观消化率均大于粗蛋白质 (P<0.05) ;各种必需氨基酸的小肠表观消化率均有差异 ,精氨酸和亮氨酸的小肠消化率通常比真蛋白高 ,色氨酸和苏氨酸的小肠消化率比真蛋白低 ,但各种必需氨基酸的小肠表观消化率并没有一致的大小顺序。与日粮相比 ,十二指肠中的必需氨基酸组成发生了较大的变化 ;与回肠流量相比 ,粪便中的必需氨基酸排泄量也发生了较大的变化。
Six 500～600kg steers with ruminal,duodenal and ileac cannula were fed with high level(HL),middle level(ML)and low level(LL)diets in turn based on corn,cottonseed meal and ammoniated rice straw.At each feeding level,crude protein(CP),true protein(TAA)and individual essential amino acid(EAA)flows at duodenum,illeum and feces were determined;apparent CP,TAA and individual EAA digestibilities in the small intestine were calculated.The results indicated that:(1)With declining of the feeding level,the apparent digestibilities of CP,TAA,Leu,Met,Trp and Val in the small intestine decreased significantly(P<0.05).(2)At each feeding level,apparent TAA digestibility was higher than that of CP.(3)There were differences between the individual EAA and TAA digestibilities at three feeding levels.The digestibilities of Arg and Leu were higher than that of TAA,the digestibilities of Trp and Thr were lower than that of TAA,but there wasn't a constant sequence among individual EAA digestibilities.(4)The EAA composition of duodenal TAA flows varied significantly in comparison with that of dietary TAA,the fecal EAA excretions also varied significantly comparing with EAA flows in the ileum.
出处
《动物营养学报》
CAS
CSCD
2002年第3期18-23,共6页
CHINESE JOURNAL OF ANIMAL NUTRITION
基金
国家"九五"科技攻关项目(96 -003)
