重组人溶菌酶对黄羽肉鸡生长性能、免疫功能和肠道健康的影响

Effects of Recombinant Human Lysozyme on Growth Performance,Immune Function and Intestinal Health of Yellow-Feathered Broilers

本试验旨在通过对生长性能、血浆和肠道免疫指标、肠道黏膜形态结构和盲肠菌群结构等指标的监测,研究重组人溶菌酶对黄羽肉鸡生长性能、免疫功能和肠道健康的影响,确定重组人溶菌酶在黄羽肉鸡饲粮中的适宜添加水平。试验采用单因素随机分组设计,选用1440只1日龄的健康快速型麻黄鸡,按照体重一致原则随机分为6个组,每组8个重复,每个重复30只鸡(公、母各占1/2)。对照组饲喂基础饲粮,抗生素组饲喂在基础饲粮中添加200 mg/kg的4%恩拉霉素的试验饲粮,4个试验组分别饲喂添加1、2、3、4 g/kg重组人溶菌酶的试验饲粮,试验期共50 d。结果显示:1)22~42日龄,4 g/kg重组人溶菌酶组平均日增重显著高于对照组(P<0.05)。1~50日龄,以2 g/kg重组人溶菌酶组平均日增重最高。2)21日龄,3 g/kg重组人溶菌酶组外周血CD4^(+)\CD8^(+)比值显著高于对照组(P<0.05)。50日龄,2 g/kg重组人溶菌酶组外周血CD3^(+)淋巴细胞亚群百分率显著高于抗生素组和1 g/kg重组人溶菌酶组(P<0.05);2 g/kg重组人溶菌酶组外周血CD4^(+)淋巴细胞亚群百分率显著高于对照组、抗生素组和1 g/kg重组人溶菌酶组(P<0.05),同时外周血CD8^(+)淋巴细胞亚群百分率显著高于抗生素组(P<0.05)。3)50日龄,1 g/kg重组人溶菌酶组空肠黏膜白细胞介素-1β(IL-1β)含量显著高于其他组(P<0.05);3 g/kg重组人溶菌酶组空肠黏膜白细胞介素-10(IL-10)和分泌型免疫球蛋白A(sIgA)含量显著高于对照组(P<0.05);3 g/kg重组人溶菌酶组空肠黏膜含量显著高于对照组和4 g/kg重组人溶菌酶组(P<0.05);3和4 g/kg重组人溶菌酶组空肠黏膜溶菌酶含量显著高于对照组(P<0.05)。4)21日龄,3 g/kg重组人溶菌酶组和抗生素组盲肠乳酸杆菌数量显著高于对照组(P<0.05)。50日龄,4 g/kg重组人溶菌酶组盲肠乳酸杆菌数量显著高于其他组(P<0.05);1和2 g/kg重组人溶菌酶组盲肠双歧杆菌数量显著高于抗生素组(P<0.05)。5)21日龄,3 g/kg重组人溶菌酶组回肠绒毛高度、绒隐比显著高于对照组(P<0.05)。50日龄,3和4 g/kg重组人溶菌酶组空肠隐窝深度显著低于对照组(P<0.05)。以上结果说明,重组人溶菌酶对黄羽肉鸡的生长性能、免疫功能和肠道健康有提高和改善作用。黄羽肉鸡饲粮中重组人溶菌酶的适宜添加水平为1~4 g/kg(10000~40000 U/kg)。

This experiment was conducted to investigate the effects of recombinant human lysozyme on growth performance,immune function and intestinal health of yellow-feathered broilers by determining the growth performance,plasma and intestinal immune indices,intestinal mucosal morphology and cecal microflora structure,and to determine the optimum supplemental level of recombinant human lysozyme in the diet of yellow-feathered broilers.A single factor test design was adopted in the experiment.A total of 1440 one-day-old yellow-feathered broilers(fast-growing ephedra broilers)were randomly divided into 6 groups with 8 replicates in each group and 30 chickens(half male and half female)in each replicate according to the similar body weight.Broilers in control group were fed a basal diet,broilers in antibiotics group were fed the basal diet supplemented with 200 mg/kg 4%enramycin,and broilers in four test groups were fed the basal diet supplemented with 1,2,3 and 4 g/kg recombinant human lysozyme,respectively.The experiment lasted for 50 days.The results showed as follows:1)from 22 to 42 days of age,the average daily gain of 4 g/kg recombinant human lysozyme group was significantly higher than that of control group(P<0.05).From 1 to 50 days of age,the average daily gain was the highest in the 2 g/kg recombinant human lysozyme group.2)At 21 days of age,the ratio of CD4^(+)to CD8^(+)in peripheral blood of 3 g/kg recombinant human lysozyme group was significantly higher than that of control group(P<0.05).At 50 days of age,the percentage of CD3^(+)lymphocyte subsets in peripheral blood of 2 g/kg recombinant human lysozyme group was significantly higher than that of antibiotic group and 1 g/kg recombinant human lysozyme group(P<0.05);the percentage of CD4^(+)lymphocyte subsets in peripheral blood of 2 g/kg recombinant human lysozyme group was significantly higher than that of control group,antibiotic group and 1 g/kg recombinant human lysozyme group(P<0.05);the percentage of CD8^(+)lymphocyte subsets in peripheral blood of 2 g/kg recombinant human lysozyme group was significantly higher than that of antibiotic group(P<0.05).3)At 50 days of age,the interleukin-1β(IL-1β)content in jejunal mucosa of 1 g/kg recombinant human lysozyme was significantly higher than that of other groups(P<0.05);the interleukin-10(IL-10)and secreted immunoglobulin(sIgA)contents in jejunal mucosa of 3 g/kg recombinant human lysozyme was significantly higher than that of control group(P<0.05);the lysozyme content in jejunal mucosa of 3 and 4 g/kg recombinant human lysozyme groups was significantly higher than that of control group(P<0.05).4)At 21 days of age,the number of lactobacillus in cecum of 3 g/kg recombinant human lysozyme group and antibiotic group was significantly higher than that of control group(P<0.05).At 50 days of age,the number of lactobacillus in cecum of 4 g/kg recombinant human lysozyme group was significantly higher than that of other groups(P<0.05);the number of bifidobacteria in cecum of 1 and 2 g/kg recombinant human lysozyme groups was significantly higher than that of antibiotic group(P<0.05).5)At 21 days of age,the ileal villus height and villus height/crypt depth of 3 g/kg recombinant human lysozyme group were significantly increased compared with control group(P<0.05).At 50 days of age,the jejunal crypt depth of 3 and 4 g/kg recombinant human lysozyme group was significantly decreased compared with control group(P<0.05).These results suggest that recombinant human lysozyme can improve the growth performance,immune function and intestinal health of yellow-feathered broilers.The optimal dietary supplemental level of recombinant human lysozyme for yellow-feather broilers is 1 to 4 g/kg(10000 to 40000 U/kg).