复合噬菌体裂解酶对白羽肉鸡肠道菌群结构和肝脏抗氧化酶指标的影响

Effects of complex phage lysin on growth performance, organ index and major antioxidant enzyme activities in white feather broilers

摘要:

[背景] 噬菌体裂解酶具有良好的安全性与抑菌特性，有望替代抗生素作为一种饲料添加剂应用于改善畜禽肠道菌群和预防动物疾病。[目的] 以白羽肉鸡为饲喂对象，分别饲喂复合噬菌体裂解酶与抗生素制剂，评估噬菌体裂解酶对畜禽肠道菌群的影响及其作为替抗饲料添加剂的应用潜能。[方法] 以三日龄健康白羽肉鸡为饲喂对象，在基础饲粮上添加由噬菌体裂解酶（TSPphg）和噬菌体裂解酶（MMPphg）获得的复合噬菌体裂解酶制剂（200 mg/kg）与50μg/g的金霉素制剂，分别进行比较饲喂管理。利用第三代测序技术对28 d时白羽肉鸡肠道菌群进行高通量测序，借助生物信息学分析肠道菌群多样性和优势菌群（丰度前10）相对丰度，揭示各分组组间与组内差异，并对肝脏主要氧化酶活性进一步比较。[结果] 饲喂复合噬菌体裂解酶和金霉素制剂对白羽肉鸡肠道菌群有一定影响，均降低了肠道菌群丰度与多样性，而且Shannon指数与空白组相比存在显著差异（P<0.05）。优势菌群中，复合噬菌体裂解酶组相较于金霉素组和空白组，拟杆菌门的相对丰度发生了显著上升，而厚壁菌门的相对丰度发生了显著下降（P<0.05）。同时，在属水平上，粪杆菌属的相对丰度发生了显著上升，而螺杆菌属的相对丰度发生了显著下降（P<0.05），这一趋势与多数替代抗生素产品饲喂家禽后肠道菌群变化趋势类似，更有利于家禽肠道的健康。此外，饲喂复合噬菌体裂解酶组相较于金霉素组和空白组，过氧化氢酶（Catalase，CAT）和超氧化物歧化酶（Superoxide Dismutase，SOD）活性均发生了显著上升（P<0.05）。[结论] 噬菌体裂解酶能够有效改善畜禽肠道菌群，促进畜禽肠道菌群的微生态健康及提高机体免疫力，将噬菌体裂解酶替代抗生素应用于畜禽养殖具有较好的前景，值得进一步研究。

关键词:噬菌体裂解酶;白羽肉鸡;抗生素替代;肠道菌群;抗氧化酶活性

Abstract:

[Background] Phage lysin has good safety and antibacterial properties, and is expected to replace antibiotics as a feed additive to improve the intestinal flora of livestock and poultry and prevent animal diseases. [Objective] White feather broilers were fed with complex phage lyase and antibiotic preparations to evaluate the effect of phage lysin on the intestinal flora of livestock and poultry and its application potential as an alternative feed additive. [Methods] Three-day-old healthy white feather broilers were fed, and the basic diet was supplemented with (200 mg/kg) complex phage lysin prepared from Thermus bacteriophage lysin (TSPphg) and Subthermus bacteriophage lysin (MMPphg) the lysin preparation and the 50 μg/g chlortetracycline preparation were respectively compared for feeding management. The high-throughput sequencing on the intestinal flora of white feather broilers at 28 days using the third-generation high-throughput sequencing technology, With the help of bioinformatics analysis of intestinal flora diversity and the relative abundance of dominant flora (top ten relative abundance), reveal the differences between and within each group, and further compare the liver oxidase activities. [Results] Complex phage lysin and chlortetracycline preparation had a certain effect on the intestinal flora of white feather broilers, both of which decreased the abundance and diversity of intestinal flora, and the Shannon index was significantly different compared with the blank group (P<0.05). In the dominant intestinal bacteria, Bacteroidetes significantly increased and Firmicutes significantly decreased in the complex phage lysin group compared with chlortetracycline group and blank group (P<0.05). At the same time, at the genus level, the relative abundance of Faecalibacterium increased significantly, while the relative abundance of Helicobacter decreased significantly (P<0.05), this trend was similar to that of most alternative antibiotic products after feeding poultry intestinal flora, which was more conducive to the health of poultry intestines. In addition, compared with chlortetracycline group and blank group, the activities of catalase (CAT) and superoxide dismutase (SOD) in complex phage lysin group were significantly increased go up (P<0.05). [Conclusion] Phage lysin can effectively improve the intestinal flora of livestock and poultry, promote the micro-ecological health of the intestinal livestock and poultry and improve the immunity of the body. It has a good prospect to replace antibiotics with phage lysin in livestock and poultry breeding and is worth further study.

Key words:phage lysin;white feather broiler;antibiotic replacement;intestinal flora;antioxidant enzyme activity