日粮中添加屎肠球菌对AA肉鸡生产性能、免疫器官指数和血液脂质代谢相关指标的影响

本试验旨在研究日粮中添加屎肠球菌对AA肉鸡生产性能、免疫器官指数和血液脂质代谢相关指标的影响，探讨屎肠球菌替代抗生素在肉鸡日粮中应用的可行性及其最适添加量。试验选取1日龄AA肉鸡公仔鸡600只（50 g/只），随机分成5组，每组6个重复，每个重复20只鸡。对照组（CON）饲喂基础日粮；抗生素组（ANT）饲喂基础日粮+0.1%金霉素；3个屎肠球菌试验组（LEF、MEF和HEF组）在基础日粮中分别添加50、100、200 mg/kg屎肠球菌。试验分2期，分别为1~21日龄（前期）和22~42日龄（后期）。结果显示：①各试验组肉鸡生长性能与CON组相比均无显著差异（P>0.05）；从饲养全期看，MEF组和HEF组AA肉鸡的死淘率最低。②在饲养后期，与CON组相比，MEF组胸腺指数显著提高（P<0.05），MEF组脾脏指数有提高的趋势（0.05 < P < 0.1）。③在饲养前期，与CON组和ANT组相比，LEF组和HEF组血清总胆固醇（TC）含量极显著降低（P<0.01）；与ANT组相比，LEF组和MEF组血清甘油三酯（TG）含量极显著降低（P<0.01）；与CON组相比，MEF组和HEF组血清高密度脂蛋白（HDL）含量极显著提高（P<0.01）；与ANT组相比，添加屎肠球菌试验组的低密度脂蛋白（LDL）含量极显著降低（P<0.01）。在饲养后期，与CON组和ANT组相比，LEF组肉鸡血清中TG含量极显著降低（P<0.01），LEF组和MEF组HDL含量极显著提高（P<0.01）。综上所述，在肉鸡饲养中，添加屎肠球菌可以在一定程度上降低死淘率，并有促进免疫器官发育的趋势，还具有一定的降低血脂的作用。综合考虑，建议在AA肉鸡日粮中添加100 mg/kg屎肠球菌。

Effects of Enterococcus faecium on Production Performance,Immune Organ Indexes and Blood Lipid Metabolism-related Indexes in AA Broilers

The aim of this study was to investigate the effects of Enterococcus faecium on the production performance,immune organ indexes and blood lipid metabolism-related indexes in AA broilers,and explore the feasibility of the application of Enterococcus faecium replaced antibiotics in broiler diet and its optimal dosage.600 1-day-old AA male broilers with 50 g body weight were chosen and randomly allocated into 5 groups with 6 replicates per group and 20 AA broilers per replicate in a complete randomized design.The five groups were CON group (basal diet),ANT group (basal diet+0.1% chlortetracycline), LEF group (basal diet+50 mg/kg Enterococcus faecium),MEF group (basal diet+100 mg/kg Enterococcus faecium) and HEF group (basal diet+200 mg/kg Enterococcus faecium).The experiment was divided into two phases with the early stage was 1 to 21 d and the later period was 22 to 42 d.The results showed as follow:①There was no significant difference in the growth performance between experimental groups and CON group (P>0.05).In the whole period,the mortality of AA broiler in MEF and HEF groups was the lowest.②In the later stage of feeding,compared with the CON group,the thymus index of MEF group was significantly increased (P<0.05),while the spleen index had a tendency to increase (0.05 < P < 0.1).③In the early stage, compared with CON and ANT groups,the content of TC in serum of LEF and HEF groups was extremely significantly decreased (P<0.01),and compared with the ANT group,the content of TG in serum of LEF and MEF groups was extremely significantly decreased (P<0.01);Compared with the CON group,the HDL content were extremely significantly increased in MEF and HEF groups in serum (P<0.05), and compared with the ANT group,the LDL content in serum of groups adding Enterococcus faecium were extremely significantly decreased (P<0.01).In the later stage, compared with the CON and ANT groups,the TG content in serum of LEF group was extremely significantly decreased (P<0.01),while HDL content in LEF and MEF groups was extremely significantly increased (P<0.01).It was concluded that Enterococcus faecium would be an ideal feed additive to reduce mortality rate to a certain extent,and promote the development of immune organ and decrease blood lipids.And the optimum supplemental level of Enterococcus faecium was 100 mg/kg under the conditions of this experiment.