不同粗蛋白质水平日粮对育肥羊小肠养分吸收率的影响

Effects of Different Dietary Crude Protein Levels on the Nutrient Absorbability in the Small Intestine of Lambs

本研究旨在比较不同粗蛋白质(CP)水平日粮对育肥羔羊小肠养分吸收率的影响。选用体重30kg左右,安装有瘤胃、十二指肠近端和回肠末端瘘管的3只哈萨克育肥羊为试验动物,采用3×3拉丁方试验设计,采用醋酸镱(Yb-Ac)、锂铬乙二胺四乙酸(LiCr-EDTA)分别作为消化道固相和液相食糜标记物测定小肠食糜流量。结果显示,增加全混合日粮中CP水平可显著提高育肥羊N的进食量、全消化道表观消化率和N沉积(P<0.05),显著提高干物质(DM)和有机物(OM)的表观消化率(P<0.05),但对小肠食糜流量无显著影响(P>0.05);提高日粮CP水平对十二指肠食糜除EE和嘌呤外的营养成分流量均产生显著的影响(P<0.05),仅对回肠食糜中CP、粗灰分(Ash)、DM、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)流量的影响显著(P<0.05),且对CP、Ash、DM、NDF和ADF的小肠吸收率影响显著(P<0.05)。本试验为进一步深入分析增加日粮CP水平对其在育肥羊体内的消化利用奠定基础。

This experiment was conducted to study the effects of different dietary crude protein levels on the nutrient absorbability in the small intestine of lambs.Three Kazakh lambs（30kg body weight）fitted with permanent ruminal,duodenal and ileal fistula were selected.3×3Latin square design was adopted.A dual-phase marker system with LiCr-EDTA and Yb-Ac as the liquid-phase or particulate-phase digesta flows maker was adopted to measure the true digesta flows at duodenal and ileal fistula,respectively.The results showed that nitrogen intake,total tract apparent digestibility,N deposition,the apparent digestibility of dry matter and organic matter were significantly increased with increasing levels of dietary crude protein（P〈0.05）,but had no significant effects on intestinal digesta flows（P〉0.05）.Increasing dietary crude protein levels had significant effects on most part of nutrients of duodenal digesta except fat and purine（P〈0.05）,while it only significantly effected CP,Ash,dry matter,neutral detergent fibre and acid detergent fiber of ileal digesta flows（P〈0.05）.In addition,intestinal absorbability of nutrients except for CP,Ash,dry matter,neutral detergent fibre and acid detergent fiber were significantly affected with increasing levels of dietary crude protein（P〈0.05）.The test provided basis for further study of the effects of dietary CP level on the digestibility and utilization of lamb.