Effects of Glutamine on Digestive Function and Redox Regulation in the Intestines of Broiler Chickens Challenged with Salmonella Enteritidis

ABSTRACT The aim was to investigate the effect of glutamine (Gln) on broilers challenged with Salmonella Enteritidis. 240 1-day-old birds were divided into four groups in a completely randomized design, each of which included 6 replicates with 10 birds per replicate. Group I served as the unchallenged, untreated control (CON). All birds in groups II (SCC) - IV were challenged with 2.0 × 104 CFU/mL of S. Enteritidis. Birds in group III and IV were treated with 0.5% (Gln 1) and 1.0% (Gln 2), respectively, of Gln. The results indicated that S. Enteritidis infection led to a decrease in the average body weight at d 7, 14, and 21 (p&lt;0.05). Chickens fed the Gln showed improved average body weights in comparison with the SCC group (p&lt;0.05). At d 4, 7, 14, and 21, the Gln groups increased digestive enzyme (trypsin, lipase and amylase (except the amylase activity of jejunum at d 14 and d 21)) activities in the intestine (p&lt;0.05), superoxide dismutase (SOD) (at d 14 jejunum; except at d 4, ileum) and catalase (CAT) (at d 4, and d 21, jejunum; d 4, ileum) activity in the serum (except at d 14) and intestinal mucosa (p&lt;0.05), and the mRNA expression of SOD, CAT and nuclear respiratory factor 2 (Nrf2) of the intestinal mucosa compared with the SCC group (p&lt;0.05). These results suggest that Gln as a feed additive could be effective for reducing the detrimental effects of S. Enteritidis infection of broilers.摘要：本研究旨在探究谷氨酰胺（glutamine, Gln）对肠炎沙门氏菌（Salmonella Enteritidis）攻毒肉鸡的干预效果。选取240只1日龄肉鸡，采用完全随机设计分为4组，每组设置6个重复单元，每个重复包含10只肉鸡。组I为未攻毒、未处理的空白对照组（CON）。组II至IV（SCC组）均以2.0×10⁴ CFU/mL的肠炎沙门氏菌进行攻毒。组III与组IV分别饲喂添加0.5%谷氨酰胺（Gln 1）与1.0%谷氨酰胺（Gln 2）的日粮。结果显示，肠炎沙门氏菌感染会导致肉鸡在第7、14、21日龄的平均体重显著降低（p<0.05）。与SCC组相比，饲喂谷氨酰胺的肉鸡平均体重显著提升（p<0.05）。在第4、7、14、21日龄，相较于SCC组，谷氨酰胺组肉鸡肠道消化酶（胰蛋白酶、脂肪酶及淀粉酶，第14、21日龄空肠淀粉酶活性除外）活性显著升高（p<0.05）；血清（第14日龄检测样本除外）及肠黏膜中超氧化物歧化酶（superoxide dismutase, SOD，第14日龄空肠除外、第4日龄回肠除外）、过氧化氢酶（catalase, CAT，第4、21日龄空肠除外、第4日龄回肠除外）活性显著升高（p<0.05）；同时肠黏膜中SOD、CAT及核呼吸因子2（nuclear respiratory factor 2, Nrf2）的mRNA表达量显著上调（p<0.05）。上述结果表明，谷氨酰胺作为饲料添加剂可有效缓解肠炎沙门氏菌感染对肉鸡造成的不良影响。