融合肽hEGF-AWRK6对肉鸡生产性能、抗氧化机能及养分代谢的影响

发布时间：2018-05-13 05:30

  本文选题：融合肽hEGF-AWRK6 + 肉鸡　； 参考：《辽宁大学》2017年硕士论文

【摘要】：抗菌肽(antibacterial peptides,ABP)是生物体内产生的一种具有广谱抗菌作用的小分子多肽,属非特异性防疫系统的重要组份。人表皮生长因子(hEGF)作为促生长因子家族成员之一,具有促进新血管形成和表皮细胞增殖的作用,是上皮细胞、表皮细胞和间充质等敏感细胞的丝裂原,具有促进生长和提高免疫的作用。抗菌肽AWRK6是经Dybowskin-2CDYa设计改造而得的新型抗菌肽,与以往发现的其它蛙类抗菌肽相比相似性小,它富含赖氨酸,具有亲水性强,稳定性高,抑菌活性强和抑菌谱广等特点。hEGF-AWRK6是由本实验室将人表皮生长因子hEGF和抗菌肽AWRK6的基因DNA连接、转化并表达纯化得到的重组融合多肽。本实验以肉鸡为实验动物,分析了融合肽hEGF-AWRK6对肉鸡生产性能、养分代谢、抗氧化和免疫机能的影响。探讨了融合肽hEGF-AWRK6替代饲用抗生素应用于家畜养殖的可行性。实验选取84只1日龄健康AA肉仔鸡,随机分4组。对照组饲喂基础日粮,实验Ⅰ组、Ⅱ组和抗生素组分别在基础日粮中添加50mg/kg、100mg/kg的融合肽hEGF-AWRK6和5mg/kg的黄霉素,实验周期为42d。结果显示:1、与对照组相比,实验Ⅱ组与抗生素组的肉鸡体重分别提高了21.4%(p0.01)和19.0%(p0.05),半净膛、全净膛和胸肌重亦显著增加,且实验Ⅱ组优于抗生素组,而各组肉鸡的全净膛率、半净膛率以及腿肌重没有显著差异;2、实验Ⅱ组肉鸡免疫器官指数、脾脏和巨噬细胞细胞活力及Sig-A水平,与对照组相比分别提高了66.67%,27.27%,68.29%和54.11%,差异显著,且实验Ⅱ组优于抗生素组。3、与对照组相比,实验Ⅱ组的肉鸡肝脏的GSH-PX、T-AOC和SOD水平分别提高了的23.07%、64.6%、10.81%,并且降低MDA水平的28.57%,差异显著。4、融合肽hEGF-AWRK6能够显著提高肉鸡肌肉蛋白质和脂肪得含量,与对照组相比,实验Ⅱ组的肌肉蛋白质和脂肪分别提高了15.89%(p0.01)和29.31%(p0.01)。此外,融合肽hEGF-AWRK6可提高肉鸡小肠绒毛高度和隐窝深度比值,降低肉鸡肠道中有害菌群大肠杆菌的数量。本文研究结论:在日料粮中添加100mg/kghEGF-AWRK6可以显著增加肉鸡的日增重,提高饲料的转化效率,提高肉鸡肌肉中蛋白和脂肪的含量;融合肽hEGF-AWRK6可提高肉鸡血清中的免疫球蛋白A(Sig-A)水平,并能显著提高肉鸡的肝脏抗氧化机能,增强肉鸡的抵抗力;融合肽hEGF-AWRK6可改善肉鸡肠道菌群和肠道结构,降低肠道中的大肠杆菌数量;日料中添加高剂量hEGF-AWRK6(100mg/kg)组的肉鸡的生产性能及免疫能力优于日料中添加抗生素组的肉鸡。本实验为hEGF-AWRK6作为饲用抗生素替代品在家畜饲养中的应用提供了实验依据。
[Abstract]:Antimicrobial peptide (ABP) is a kind of small molecular peptide with broad-spectrum antimicrobial activity produced in vivo, which is an important component of nonspecific epidemic prevention system. Human epidermal growth factor hEGF, as a member of the growth promoting factor family, is a mitogen of epithelial cells, epidermal cells and mesenchymal cells, which can promote the formation of new blood vessels and the proliferation of epidermal cells. It has the function of promoting growth and improving immunity. Antimicrobial peptide AWRK6 is a new antimicrobial peptide designed and modified by Dybowskin-2CDYa. It has less similarity with other frog antimicrobial peptides found in the past. It is rich in lysine, has strong hydrophilicity and high stability. HEGF-AWRK6 is a recombinant fusion polypeptide which is expressed and expressed by the DNA of human epidermal growth factor (hEGF) and antimicrobial peptide AWRK6 (AWRK6), which is characterized by strong bacteriostatic activity and wide antimicrobial spectrum. The effects of fusion peptide hEGF-AWRK6 on performance, nutrient metabolism, antioxidation and immune function of broilers were studied. The feasibility of using fusion peptide hEGF-AWRK6 instead of feeding antibiotics in livestock breeding was discussed. Eighty-four 1-day-old AA broilers were randomly divided into 4 groups. The control group was fed with basal diet, experimental group 鈪，

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