奶牛肠道微生物群落结构与多样性研究

发布时间：2018-07-04 17:34

本文选题：肠道菌群 + 高通量测序　；参考：《河北工程大学》2017年硕士论文

【摘要】：我国是世界上的牛奶消费大国,奶牛的养殖规模较大。奶牛作为反刍动物,可以利用单胃动物难降解的粗纤维物质并经过生理代谢将其转化为人类可以利用的奶、肉等动物性蛋白。肠道菌群在奶牛营养物质的消化代谢中具有关键作用,合理的肠道菌群可以明显的改善奶牛的生理健康水平、提高能量利用率。从微生物生态学角度出发,健康机体中肠道微生物群落相对稳定,同时受肠道内环境、生存环境和日粮等多种因素的影响。本论文以不同生长时期和不同饲养环境下的奶牛为研究对象,分别研究了奶牛肠道微生物的变化特征及其对海拔、土壤微生物环境变化的响应,并从机体肠道内源益生菌的新视角发现了奶牛肠道菌群与泌乳性能的关系。本课题主要从以下几个方面进行研究:1.为了探究不同生长期的奶牛肠道菌群变化规律,使用Hi Seq2500测序平台,对比分析了奶牛的哺乳期、断奶期、育成期、青年期、泌乳期和干奶期的肠道菌群结构组成及多样性特征,分析发现了肠道菌群与生长性能的变化规律,同时还发现肠道菌群中某些益生菌属与泌乳性能可能存在一定的相关性。差异性分析结果显示不同生长期的奶牛肠道菌群在门水平上保持相对稳定;随着犊牛的生长,肠道菌群逐渐定植,在育成前后多样性呈现“两段式”格局;此外,益生菌属中双歧杆菌属的丰度在泌乳期显著高于其他生长期,并与产奶量呈正相关关系。2.为了验证奶牛肠道益生菌属与泌乳性能的关系,对比分析了高海拔奶牛在泌乳期与非泌乳期的肠道菌群结构及多样性差异,着重对比了不同益生菌属的丰度变化。结果显示,高海拔奶牛肠道菌群结构在泌乳期和非泌乳期在门水平上没有明显变化,而在泌乳期少数菌属的丰度显著降低;肠道菌群的丰富度(α多样性)无显著差异,基于非加权的主坐标分析结果显示泌乳期与非泌乳期各自聚类明显;在泌乳期,益生菌属中双歧杆菌属的丰度显著高于非泌乳期,而其他两种益生菌属丰度差异不显著。3.为了探究奶牛肠道菌群对海拔因素的生态适应性,分析了高原奶牛与平原奶牛肠道菌群的差异。结果发现,二者在门水平保持相对稳定且存在主要核心菌属,高海拔奶牛肠道菌群与平原奶牛各自差异聚类明显,少数肠道菌属存在显著差异,双歧杆菌属在高海拔奶牛肠道菌群中相对丰度较低。4.为了探究不同养殖方式对高原奶牛肠道菌群的影响,对比分析了放牧与标准化圈养两种养殖方式下肠道菌群结构及多样性差异。分析结果表明,不同养殖方式的奶牛在门属水平上均存在差异显著的菌群,圈养产奶牛肠道菌群丰富度(α多样性)较高,且基于Unifrac距离的主坐标分析结果显示各自聚类明显。5.为了探究高原放牧区土壤微生物对奶牛肠道菌群的影响,分析了同一海拔不同生境的土壤微生物与放牧奶牛肠道微生物的关系。结果发现,不同自然环境下的土壤微生物菌群结构及多样性差异显著,其结构组成不同于牛肠道微生物,且高原放牧区奶牛肠道菌群与土壤微生物群落结构间某些菌属存在显著相关性;但是,不同放牧区奶牛肠道菌群并未随着土壤微生物的变化发生显著变化。通过研究可以得出结论,奶牛的肠道菌群是由核心菌群与可变菌群构成,且菌落结构在门水平上保持相对稳定,高原奶牛的肠道菌群可能对海拔表现了生态适应性,肠道微生物与土壤微生物在属水平上有相关关系,值得注意的是,我们发现肠道益生菌属(双歧杆菌属)的丰度与高原及平原标准化圈养奶牛的泌乳性能均存在相关性,且可能与产奶量的高低有关。
[Abstract]:China is a big country of milk consumption in the world. As a ruminant, it can be used as a ruminant, which can be transformed into human milk, meat and other animal proteins, which are difficult to be degraded by the single stomach animal and through physiological metabolism. The intestinal flora plays a key role in the digestion and metabolism of dairy nutrition. The rational intestinal flora can obviously improve the physiological health level of the dairy cows and improve the energy utilization rate. From the perspective of microbial ecology, the intestinal microorganism community in the healthy body is relatively stable, and is influenced by various factors such as the intestinal environment, the living environment and the diet. This paper is based on different growth periods and different feeding environments. As the research object, the change characteristics of the intestinal microorganism and the response to the change of the soil microbial environment were studied, and the relationship between the intestinal microflora and the lactation performance was found from the new perspective of the endogenous probiotics in the intestinal tract. This subject was mainly studied in the following aspects: 1. to explore the difference between the dairy cows and the dairy cows. The changes of intestinal microflora in the growth period of dairy cows, using Hi Seq2500 sequencing platform, compared and analyzed the structure and diversity of intestinal microflora in lactating, weaning, young, young, lactation and dry milk period of dairy cows, and found the regularity of intestinal microflora and growth performance, and also found some intestinal flora. There may be a certain correlation between probiotics and lactation performance. The difference analysis shows that the intestinal flora of dairy cows in different growth periods is relatively stable at the gate level; with the growth of calves, the intestinal flora is gradually planted, and the diversity of the intestinal flora appears "two stages" pattern before and after breeding; in addition, the Bifidobacterium in the probiotic genus is abundant. In order to verify the relationship between the intestinal probiotics and the lactation performance of the dairy cows, the relationship between the milk production and the milk production was positively correlated with the milk production period. The differences in the intestinal flora structure and diversity of dairy cows at high altitude in lactation and non lactation periods were compared and analyzed, and the abundance changes of different probiotics were contrasted. The results showed that the abundance changes of different probiotics were contrasted. The results showed that.2. There was no significant change in the intestinal microflora structure at the lactating and non lactation stages in the lactating and non lactation periods, but the abundance of the genus in the lactation period decreased significantly, and the abundance of the intestinal flora (alpha diversity) had no significant difference. The results of the non weighted principal coordinate analysis showed that the lactation period and the non lactation period were distinct; in lactation period, The abundance of bifidobacteria in probiotics was significantly higher than that in the non lactation period, while the difference of the abundance of the other two probiotics was not significant.3. in order to explore the ecological adaptability of the intestinal flora and the intestinal flora of the plateau cows and the plain cows. The results showed that the two were relatively stable and dominant in the gate level. For the core bacteria, the difference between the intestinal microflora and the plain dairy cows in high altitude dairy cows is distinct, and there are significant differences in the number of intestinal microflora. The relative abundance of Bifidobacterium in the intestinal microflora of high altitude dairy cows is lower.4. in order to explore the effects of different culture methods on the intestinal flora of plateau cows, and the grazing and standardized captivity are compared and analyzed two. The differences in the structure and diversity of intestinal microflora in the breeding methods showed that there were significant differences in the level of the families of the cows with different culture methods, and the richness of the intestinal flora (alpha diversity) in the captive dairy cows was higher, and the main coordinate analysis based on the Unifrac distance showed that each cluster was obviously.5. in order to explore the plateau. The effects of soil microbes on the intestinal microflora of dairy cattle were analyzed. The relationship between soil microbes in different habitats at the same altitude and the intestinal microflora of grazing cows was analyzed. The results showed that the structure and diversity of soil microbial flora in different natural environments were distinct, and their structure was different from bovine intestinal microorganism and plateau grazing area milk. There is a significant correlation between the bovine intestinal flora and the soil microbial community structure, but the intestinal microflora of cows in different grazing areas did not change significantly with the change of soil microbes. The results of the study can be concluded that the intestinal flora of dairy cows is composed of core and variable bacteria groups, and the colony structure is on the gate level. The intestinal microflora of plateau dairy cows may have the ecological adaptability to the altitude, and there is a correlation between the intestinal microorganism and the soil microorganism. It is worth noting that the abundance of the intestinal probiotics (Bifidobacterium) is found to be related to the lactating performance of the plateau and plain standardized captive dairy cows. And it may be related to the level of milk production.
【学位授予单位】：河北工程大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S823

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