皮质酮应激改变了肉仔鸡的肠道形态和功能

Corticosterone Administration Alters Small Intestinal Morphology and Function of Broiler Chickens

本研究通过2个饲养试验旨在研究日粮添加皮质酮对肉仔鸡小肠形态和消化吸收功能的影响。试验1中,120只8日龄肉仔鸡随机分为2组,每组6个重复,每个重复10只鸡。试验2中,108只8日龄肉仔鸡随机分为2组,每组9个重复,每个重复6只鸡。对照组饲喂基础日粮;试验组日粮由每千克基础日粮添加30 mg皮质酮组成。21日龄时,测定肉仔鸡生产性能、小肠形态特征、血浆木糖水平、小肠食糜消化酶活性、养分消化率及小肠黏膜上皮细胞5-溴-2-脱氧鸟苷酸(BrdUrd)标记指数。结果表明,皮质酮诱导的应激显著降低了肉仔鸡日增重、采食量和饲料效率;显著降低了十二指肠和空肠绒毛高度及隐窝深度;显著降低了血浆中木糖水平及十二指肠和空肠黏膜上皮细胞的BrdUrd标记指数(P<0.05)。同时,皮质酮显著提高了肉仔鸡小肠食糜中胰蛋白酶和淀粉酶活性,但显著降低了蛋白质表观消化率(P<0.05)。由此可知,采食含有皮质酮的日粮,使肉仔鸡小肠绒毛高度降低,小肠吸收功能下降,但由于消化酶活性提高,因此消化功能提高。

Two experiments （Exp.） were carried out to research the effect of corticosterone （CORT） administration on intestinal morphology and function of broilers. In Exp. 1, 120 8-day-old male broilers were randomly allocated into 2 groups with 6 replicates per group and 10 broilers per replicate. In Exp. 2, 108 8-day-old male broilers were allocated randomly to 2 groups with 9 replicates per group and 6 broilers per replicate. The chickens in control group were given basal diet. While in another experimental group （CORT）, chickens were given basal diet ＋ 30 mg CORT/kg diet. At the age of 21 days, production performance, morphological characteristics of intestine, D-xylose level in plasma, activities of digestive enzymes in digesta, digestibility of nutrients, and 5-bromo-2-deoxyuridine （BrdUrd）-labelling index of intestinal epithelial cell of broiler chickens were measured. The results implied that CORT administration decreased daily gain, feed intake, and feed efficiency （P〈0.05）; obviously decreased villus height, and crypt depth of duodenal and jejunal （P〈0.05）, the D-xylose level in plasma （P〈0.05） and the BrdUrd-labelling indices of duodenal and jejunal epithelial cell （P〈0.05）. Meanwhile, CORT administration increased the activities of trypsin, amylase （P〈0.05）; but decreased the apparent digestibility of protein （P〈0.05）. In conclusion, CORT administration decreases height of small intestinal villus and absorptive capacity of broilers, but increases the digestive capacity of broilers for the increased digestive enzymes.