抗菌肽对蛋用仔公鸡血液免疫指标和肠道菌群的影响

本试验旨在研究饲粮中添加不同水平天蚕素抗菌肽对海兰褐蛋用仔公鸡血液免疫指标和肠道菌群的影响。选用336只1日龄健康海兰褐蛋用仔公鸡,随机分为7组,每组4个重复,每个重复12只鸡。各组分别饲喂基础饲粮(对照组)、基础饲粮+150 mg/kg金霉素(抗生素组)、基础饲粮+150、200、250、300、350 mg/kg抗菌肽(抗菌肽Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ组),试验期为42 d。结果表明:1)抗菌肽Ⅳ、Ⅴ组免疫球蛋白A含量显著高于对照组和抗生素组(P<0.05);各组免疫球蛋白G含量显著高于对照组(P<0.05),抗菌肽Ⅱ、Ⅲ、Ⅳ、Ⅴ组免疫球蛋白G含量显著高于抗生素组(P<0.05);各组免疫球蛋白M含量差异不显著(P>0.05)。2)抗菌肽组补体3含量显著高于对照组和抗生素组(P<0.05),各组补体4含量差异不显著(P>0.05),抗生素组、抗菌肽Ⅲ、Ⅳ、Ⅴ组溶菌酶含量显著高于对照组(P<0.05)。3)各组大肠杆菌数量与对照组相比均显著降低(P<0.05),而抗菌肽Ⅲ、Ⅳ、Ⅴ组显著低于抗生素组(P<0.05);抗菌肽Ⅱ、Ⅲ、Ⅳ、Ⅴ组双歧杆菌数量与对照组相比显著提高(P<0.05);抗菌肽Ⅳ、Ⅴ组乳酸杆菌数量显著高于对照组(P<0.05),各抗菌肽组乳酸杆菌数量与抗生素组差异不显著(P>0.05)。由此可见,饲粮中添加不同水平抗菌肽可在一定程度上提高蛋用仔公鸡免疫力,增加肠道益生菌双歧杆菌和乳酸杆菌的数量,并能够有效降低肠道致病菌大肠杆菌数量,添加量为350 mg/kg时效果较好。

Antimicrobial Peptides:Effects on Blood Immune Indices and Intestinal microflora of Young Roosters for Egg Production

This experiment was conducted to investigate the effects of antimicrobial peptides on blood immune indices and intestinal microflora of young roosters for egg production.Three hundred and thirty-six 1-day-old healthy Hy-Line Brown young roosters for egg production were selected,and randomly divided into seven groups with four replicates in each group and twelve chicks in each replicate.The young roosters in the seven groups were fed a basal diet(control group),the basal diet+150 mg/kg aureomycin(antibiotics group),and the basal diet+150(ABPs group Ⅰ),200(ABPs group Ⅱ),250(ABPs group Ⅲ),300(ABPs group Ⅳ),350 mg/kg ABPs(ABPs group Ⅴ),respectively.The feeding experiment lasted for 42 days.The results showed as follows: 1) the immunoglobulin A content in ABPs groups Ⅳ and Ⅴ was significantly higher than that in control group and antibiotics group(P<0.05),immunoglobulin G content in the other groups was significantly higher than that in control group(P<0.05),and immunoglobulin G content in ABPs groups Ⅱ,Ⅲ,Ⅳ,Ⅴ was significantly higher than that in antibiotics group(P<0.05),but there was no significant difference in immunoglobulin M content among all groups(P>0.05).2) The complement 3 content in all ABPs groups was significantly higher than that in control group and antibiotics group(P<0.05),but there was no significant difference in complement 4 content among all groups(P>0.05).Lysozyme content in antibiotics group and ABPs groups Ⅲ,Ⅳ,Ⅴ was significantly higher than that in control group(P<0.05).3) The number of Escherichia coli in the control group was significantly lower than that in the other groups(P<0.05),and ABPs groups Ⅲ,Ⅳ and Ⅴ was significantly lower than that in antibiotics group(P<0.05);the number of Bifidobacterium in ABPs groups Ⅱ,Ⅲ,Ⅳ and Ⅴ was significantly higher than that in control group(P<0.05);the number of Lactobacillus in ABPs groups Ⅳ and Ⅴ was significantly higher than that in control group(P<0.05);and there was no significant difference in the number of Lactobacillus between all ABPs groups and antibiotics group(P>0.05).In conclusion,adding different levels of antibacterial peptides in the diet can improve the immunity of young roosters for egg production,increase the number of Bifidobacterium and Lactobacillus of intestinal probiotics,and effectively decrease the number of Escherichia coli of pathogenic bacteria.The optimal added amount is 350 mg/kg.