益生菌调控柔嫩艾美耳球虫感染鸡效果研究

发布时间：2018-01-30 01:11

本文关键词： 鸡益生菌柔嫩艾美耳球虫测序鼠李糖乳杆菌盲肠　出处：《河南科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：鸡的球虫病是由一种或几种球虫寄生于鸡肠道上皮细胞内,从而导致肠道组织病变及肠道菌群的破坏。鸡球虫病呈全球性分布,在当今养禽业普遍存在且在世界范围内影响较大,集约化养鸡业最为多发,往往造成巨大的经济损失且对养禽业生产发展产生重大的影响。据统计,全世界养禽业每年因鸡球虫病导致的经济损失可达3亿美元。柔嫩艾美耳球虫(Eimeria tenella)俗称盲肠球虫,是危害性最为严重的球虫。随着化学药物的不断使用,禽体内药物残留和球虫耐药性的问题已经成为社会目前关注的焦点。因此,寻求一种高效、安全低毒的抗球虫药物已然成为当前亟需解决的问题。本研究通过对盲肠微生物测序发现,以益生菌枯草芽孢杆菌、鼠李糖乳杆菌和酵母菌为添加物来探讨益生菌对E.tenella感染鸡的保护效果研究。主要通过下面几个实验进行研究:(1)E.tenella感染鸡盲肠微生物的测序建立E.tenella感染模型,分为对照组和感染组,在感染第14天后,分别采集感染组和对照组盲肠组织,提取盲肠内容物微生物基因组DNA,然后对其进行测序。实验结果显示:在Alpha多样性分析中,感染组与对照组相比,感染组ACE的值增加16.86,Chao1值增加18.4,Simpson值增加0.01;E.tenella感染后对微生物群落影响较大,改变了鸡盲肠内微生物不同菌群在门和属水平上的相对丰度;在Beta多样性分析中,对照组的样品间空间距离较近而感染组的样品间空间距离较远。(2)益生菌对E.tenella感染鸡保护作用建立E.tenella感染鸡试验模型,以临床症状、血便记分、存活率、增重率、和益生菌对E.tenella的保护效果研究。结果显示:益生菌的添加能减轻球虫感染鸡的血便计分,显著降低了球虫感染鸡的死亡率,提高球虫病感染鸡的增重率。益生菌抗球虫指数为137,为低效抗球虫试剂。表明益生菌可以与其它饲料添加剂联合应用于临床球虫病的防治。(3)益生菌对E.tenella感染鸡盲肠组织结构及免疫细胞的影响建立E.tenella感染鸡试验模型,在接种球虫第7天,称重后取鸡盲肠组织,用HE染色观察盲肠组织病理学变化,采用AB-PAS和PAS染色法,来观察E.tenella感染鸡盲肠杯状细胞糖原和粘液成分的变化。实验结果表明:对照组,盲肠黏膜层的糖原及粘液成份分布正常,排列有序。E.tenella感染后,造成盲肠黏膜层被破坏,大量的糖原及粘液丢失。结论:E.tenella感染鸡后改变了鸡盲肠内微生物不同菌群在门和属水平上的相对丰度;在E.tenella感染后添加益生菌能有效减轻鸡的粪便计分,提高球虫病感染鸡的增重率,提高了鸡的抗球虫指数和感染鸡的存活率;益生菌呈现出低效抗球虫的作用;同时,添加益生菌可减轻盲肠肠黏膜和肠腺组织的病理学结构的损伤,明显改善鸡的肠道粘膜免疫,进而发挥了抗球虫作用。
[Abstract]:Coccidiosis of chicken is parasitic by one or more coccidiosis in the intestinal epithelial cells, resulting in intestinal tissue lesions and the destruction of intestinal flora. Chicken coccidiosis is distributed globally. In today's poultry industry is widespread and has a greater impact in the world, intensive chicken industry is the most frequent, often resulting in huge economic losses and the development of poultry industry has a significant impact. According to statistics. The annual economic loss caused by chicken coccidiosis in the world poultry industry can reach US $300 million. Eimteneria tenella (Eimteneria ella) is commonly known as cecum coccidia. With the continuous use of chemical drugs, the problems of drug residues and coccidiosis resistance in poultry have become the focus of attention. Therefore, to seek a high efficiency. Safety and low toxicity anti-coccidiosis drugs have become a problem that needs to be solved. Through sequencing of cecum microbes, we found the probiotics Bacillus subtilis. The protective effect of probiotics on E. tenella infected chicken was studied by using Lactobacillus rhamnoides and yeast as additives. E. tenella infection model was established by sequencing of E. tenella infected chicken cecum microbes. It was divided into control group and infection group. After 14 days of infection, the cecum tissues of infection group and control group were collected, and the microbial genomic DNA of cecum contents were extracted. Then it was sequenced. The results showed that in the analysis of Alpha diversity, the value of ACE in the infected group was increased by 16.86%, and the value of Chao1 was increased by 18.40% in the infected group as compared with the control group. Simpson increased by 0.01; E. tenella infection had a great influence on the microbial community, which changed the relative abundance of different microflora in chicken cecum at phylum and genus level. In Beta diversity analysis. The experimental model of E. tenella infected chicken was established by probiotics on the protection of E. tenella infected chicken. The clinical symptoms, blood stool score, survival rate, weight gain rate and the protective effect of probiotics on E. tenella were studied. The results showed that probiotics could reduce the blood stool score of coccidiosis infected chicken. The mortality rate of chickens infected with coccidiosis was significantly reduced and the weight gain rate of chickens infected with coccidiosis was increased. The probiotic index against coccidiosis was 137. It is indicated that probiotics can be combined with other feed additives to control clinical coccidiosis. Effects of probiotics on the tissue structure and immune cells of the cecum of E. tenella infected chicken, the experimental model of E. tenella infected chicken was established. On the 7th day of inoculation of coccidia, the cecum tissues were taken from chickens after weighing, and the histopathological changes of cecum were observed by HE staining. AB-PAS and PAS staining were used. To observe the changes of glycogen and mucus in goblet cells of the caecum infected with E. tenella. The results showed that the glycogen and mucus in the mucosal layer of the caecum were normal in the control group. After infection, the cecum mucous layer was destroyed. Conclusion the relative abundance of different microflora in the cecum of chicken was changed after infection with E. tenella at the phylum and genus level. The addition of probiotics after E. tenella infection can effectively reduce the fecal score of chickens, increase the weight gain rate of coccidiosis infected chickens, improve the anti-coccidiosis index and the survival rate of infected chickens. Probiotics showed low effect against coccidiosis. At the same time, the addition of probiotics could reduce the pathological structure of caecum mucosa and intestinal gland, improve the intestinal mucosal immunity of chicken, and then play an anti-coccidial effect.
【学位授予单位】：河南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S858.31

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