融合肽hEGF-AWRK6对肉鸡生产性能及抗氧化和免疫机能的作用

摘要

融合肽hEGF-AWRK6(EK)是项目组在前期研究工作中利用大肠杆菌重组表达系统,表达纯化得到的融合多肽,具有人表皮生长因子hEGF和抗菌肽AWRK6的双重功能.为探讨EK对AA肉鸡生产性能、肝脏抗氧化水平、免疫功能的影响,本研究选取84只1日龄健康AA仔肉鸡,随机分4组.对照组肉鸡饲喂基础日粮,试验Ⅰ组肉鸡饲喂添加50mg·kg-1EK的基础日粮,试验Ⅱ组肉鸡饲喂添加100mg·kg-1 EK的基础日粮,抗生素组肉鸡饲喂添加5mg·kg-1黄霉素的基础日粮,饲喂周期为42d.分别于试验的21d和42d,使用丙二醛(MDA)、超化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)、总抗氧化能力(T-AOC)和鸡分泌型免疫球蛋白A(Sig-A)检测试剂盒,测定各组肉鸡相应指标的含量.结果表明:与对照组相比,饲喂添加EK的饲料显著提高了试验组肉鸡的体重、半净膛重与全净膛重,提高了肉鸡肝脏的SOD、GSH-PX活性水平,降低了MDA含量,同时肉鸡的免疫器官指数、巨噬细胞数量、脾脏细胞增殖能力和血清中Sig-A水平也显著提高.其中,试验组Ⅱ肉鸡的体重、半净膛重、全净膛重和肝脏抗氧化水平差异显著(p<0.05),免疫器官指数和巨噬细胞的增殖能力差异极显著(p<0.01).EK对试验组肉鸡的半净膛率和全净堂率没有显著影响.融合肽EK能显著提高肉鸡的生长性能、肝脏抗氧化水平和免疫功能,具有替代饲料中抗生素的应用前景.%Fusion polypeptide hEGF-AWRK6 (EK), which has the dual functions of inhibiting bacterial growth and promoting cell proliferation, was expressed in Escherichia coli recombinant expression system and purified in the preliminary study. The purpose of this study was to explore the effects of EK on growth performance, slaughter performance, immune functions and antioxidant levels in broilers. Eighty-four AA broilers of one day-old were randomly divided into four groups, and fed with the basal diet (control group), the basal diet + 50 mg·kg-1 EK (GroupⅠ), the basal diet + 100 mg·kg-1 EK (GroupⅡ), the basal diet + 5mg·kg-1 flavomycin (Group Ⅲ). The experimental period was 42 d. The determination of the corresponding indicators of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), total antioxidant capacity (T-AOC) and chicken secretory immunoglobulin A (Sig-A) of each group were respectively detected by each detection kit on 21d and 42d. The results showed that in comparison with the control group, the body weight, the half and whole eviscerated weight, the activity of SOD and GSH-PX in liver of group Ⅰ and Ⅱ broilers increased, and the MDA contentof liver was lowered. Meanwhile the immune organ index, number of macrophages, the spleen cell proliferation ability and the level of Sig-A of group Ⅰ and Ⅱ broilers also increased compared with the control group. Among them, the differences of body weight, the half and whole eviscerated weight, the activity of SOD, GSH-PX and MDA content of liverin group Ⅱ broilers were significant at p<0.05, immune organ index and number of macrophages were significant at p<0.01. The rate of half and whole eviscerated weight of broilers had no significant changes between the control and experimental groups. In summary, the result of this study indicated that EK had significantly good effect on growth performance, antioxidant and immunity ability of broilers, and it could be taken as a candidate of antibiotic used in livestock and poultry feed.