β-1,3-葡聚糖对感染大肠杆菌肉鸡肠道氧化还原状态、菌群状态和免疫功能的影响

Effect of Dietary β-1,3-glucan Supplementation on Intestinal Redox,Microflora and Immune Functions of Broilers Challenged with Escherichia coli

试验选择90只1日龄AA肉鸡随机分成3组,分别饲养于隔离器中。处理1和2饲喂基础日粮,处理3饲喂添加葡聚糖的试验日粮。处理2和3在8、9和10日龄连续口服感染大肠杆菌O780.5mL(浓度为1×1010cfu/mL)。处理1组鸡在8、9和10日龄口腔接种等剂量的灭菌PBS。结果表明,大肠杆菌O78感染会显著降低鸡生长速度(P<0.05),提高死亡率,使感染初期小肠氧化损伤,显著降低肠道乳酸菌数和肠道sIgA量(P<0.05),但显著提高感染初期血清特异性IgG和感染后期空肠sIgA和血清特异性IgG水平(P<0.05)。而日粮添加葡聚糖降低肉鸡死亡率,缓解因感染引起的生长速度降低,减轻肠道氧化损伤,增强肠黏膜抗氧化能力,显著提高感染后期肠道乳酸细菌数量和感染后期血清特异性IgG水平。

Ninety one-day-old male broiler chicks （AA）were randomly divided into equal groups and placed i 3 isolation chambers respectively. The group 1 and 2 were fed a standard non-medicated diet,and the group 3 receiv. the same diet supplemented with β-1,3-glucan. At d 8,9 and 10,each bird in the group 2 and 3 was challeng, with 0.5 mL of serotype On strain of E.coil （1×10^10 cfu/mL）. Results indicated that the E.coil On-challenged birds decreased BW （P〈0.05）,numerically increased mortality rate. Moreover, intestinal mocusa injury,increased jejunal and ileal sIgA contents （P〈0.05）,lower cecal lactobacilli population were also observed compared with the unchallenged birds fed an unmedicated diet. In contrast,dietary -β-1,3-glucan supplementation could significantly prevent the reduction in EW （P〈0.05） of birds, and decrease birds mortality numerically after challenge. Moreover,β-1,3-glucan could regulate the equilibrium of intestinal redoxes,induce serum specific IgG production and increase the number of cecal lactobacilli.