天蚕素抗菌肽对肉鸡感染鼠伤寒沙门氏菌的保护作用

Protective Effect of Cecropin Antimicrobial Peptides on Broilers Infected with Salmonella Typhimurium

为研究抗菌肽对感染鼠伤寒沙门氏菌肉鸡的保护作用,试验研究了不同剂量天蚕素抗菌肽对感染肉鸡生长性能、病理变化、血清和肠道免疫指标的影响。试验将240只1日龄红玉380肉仔鸡(公鸡)随机分为4组:对照组、低剂量组、中剂量组、高剂量组。对照组饲喂基础日粮,低、中、高剂量组分别在基础日粮中添加500 g/t、1000 g/t和1500 g/t天蚕素抗菌肽,试验鸡10日龄时各组灌服1 mL 1×10^(8) cfu/mL鼠伤寒沙门氏菌,试验期为28 d。结果显示:与对照组相比,中、高剂量组平均日增重显著提高(P<0.05),料重比显著降低(P<0.05),28日龄肉鸡血清IgM、IgG、IgA、IL-6、IL-10含量和肠道组织中分泌型免疫球蛋白(sIgA)、紧密连接蛋白(ZO-1)含量均显著提高(P<0.05)。综上所述,饲粮添加天蚕素抗菌肽能改善感染鼠伤寒沙门氏菌肉鸡的生长性能,提高免疫力,对感染肉鸡具有一定的保护作用;本试验条件下,适宜添加量为1500 g/t。

In order to study the protective effect of antimicrobial peptide on broilers infected with Salmonella Typhimurium,the experiment was carried out to study the effect of cecropin antimicrobial peptide with different doses on growth performance,pathological changes,serum and intestinal immune indexes of infected broilers.Two hundred and forty Hongyu 380 one-day-age broilers were randomly divided into 4 groups:The control group,low dose group,medium dose group and high dose group.The control group was fed with the basal diet,and the low,medium and high dose groups were fed with basal diet supplemented with the cecropin antimicrobial peptide of 500 g/t,1000 g/t and 1500 g/t respectively.At the age of 10 days,each group was orally infected with 1 mL of 1×10^(8) cfu/mL Salmonella Typhimurium.The test period was 28 days.The results showed that com⁃pared with the control group,the average daily weight gain of the medium and high dose groups was significantly higher(P<0.05),the feed-to-weight ratio was significantly lower(P<0.05),the content of serum IgM,IgG,IgA,IL-6 and IL-10,the levels of se⁃cretory immunoglobulin(sIgA)and tight junction protein(ZO-1)in the intestinal tissues of broilers at 28 days of age were signifi⁃cantly increased(P<0.05).In conclusion,the addition of cecropin antimicrobial peptide to feed could improve growth performance and immunity of Salmonella Typhimurium-infecting broilers,and have a protective effect on broilers,and the suitable dosage was 1500 g/t in diet under the condition of experiment.