谷氨酰胺对肉仔鸡小肠发育及吸收功能的影响

240只1日龄艾维茵肉仔鸡,随机分为4组,1组为对照组,2～4组为试验组,各组分别在基础日粮中添加0、0.2%、0.4%及0.8%的谷氨酰胺(Gln),研究Gln对肉鸡小肠发育、结构及吸收功能的影响。结果表明,饲料中添加Gln可明显提高肉鸡小肠的长度、重量及指数,2周龄时高剂量组(0.8%)效果较好,3、4周龄时则低剂量组(0.2%)较好,其中,空肠受日粮Gln影响最大,回肠次之,十二指肠最小;对肠道形态、结构的组织学观察发现,日粮中添加0.2%的Gln可显著提高试验期间空肠绒毛的高度,降低绒毛的宽度和固有膜厚度;以D-木糖吸收率为代表的小肠主动吸收功能试验表明,试验组肉鸡血清木糖浓度均高于同期对照组肉鸡。上述结果显示,外源性Gln作为肠粘膜细胞的能量来源,对促进小肠发育、维持小肠粘膜的完整性以及提高小肠的主动吸收功能有着重要作用。

Effect of Glutamine Supplementation on Development of Small Intestine, Structure and Absorption of Broilers

240 one-day-old Avian broilers were randomly divided into 4 groups, with 60 birds in each group. Group 1 served as control, while group 2 to 4 were respectively supplemented with 0.2%, 0.4% and 0.8% glutamine (Gln) in basal diet for 28 days, and the effects of dietary Gln (glutamine) supplementation on the development of small intestine, structure and absorption functions in broilers were studied. The results indicated that dietary glutamine supplementation significantly increased the length, weight and index of small intestine of the birds in the experimental groups, and 0.8% Gln in the diet had more evident effects on the development of small intestine before 2-week-old, but 0.2% Gln supplementation was sufficient for broilers on 3 or 4-week-old. The jejunum was the first part influenced by dietary Gln, the ileum took second place and the duodenum was less affected. The histological observation indicated that villus height in jejunum was greater (P<0.05), but the villus width and the lamina depth of jejunum significantly decreased in 0.2% Gln supplemented group compared with control. The serum D-xylose detection indicated that the D-xylose concentration was greater in the Gln-supplemented groups than that of the control group during the experimental period. All the results above implied that as the main fuel for the intestinal mucosal cells under stress conditions, exogenous Gln might play an important role in facilitating the proliferation of mucosal cells, maintaining intestinal modality and improving the active absorption function.