鹅肠道菌群对日粮纤维响应规律及其功能研究

发布时间：2018-06-23 01:43

本文选题：鹅 + 肠道　；参考：《吉林农业大学》2016年博士论文

【摘要】：鹅属于禽类,但可消化利用高纤维日粮,揭示鹅消化粗纤维的机制对于粗饲料资源的开发及利用有着重要的意义。本研究采用分子微生态学、动物营养学和生物学等方法研究了鹅肠道菌群对不同纤维源和纤维水平日粮的响应规律,并分离筛选出纤维素分解菌及其优化组合,为揭示鹅消化利用日粮纤维的机制提供参考。选取35日龄健康卡洛斯鹅180只(公母各半),随机分为4组,每组45只,每组3个重复,分别饲喂以玉米秸秆和苜蓿为纤维源、纤维水平分别为5%和8%的日粮,饲养期为42 d,采用消化代谢试验、屠宰试验和MiSeq PE300测序平台等测定养分消化代谢率、肠道消化酶活性、血液生化指标和肠道菌群结构,分离筛选纤维分解菌及其优化组合。结果表明:1、提高日粮纤维水平可显著提高鹅采食量、NDF和ADF的消化率、胸腺指数、法氏囊指数和脾脏指数,增加回肠、盲肠中纤维素酶和胰蛋白酶活性。对CP代谢率无显著影响。不同纤维源及纤维水平日粮在CP、CF、NDF和ADF消化率上有显著差异。纤维水平为5%时,秸秆组胰蛋白酶活性和碱性磷酸酶水平显著高于苜蓿组,而胸腺指数低于苜蓿组;纤维水平为8%时,苜蓿组胸腺指数和空肠中纤维素酶活性显著低于秸秆组,而回肠和盲肠中纤维素酶活性显著高于秸秆组。2、二种纤维源,当提高日粮纤维水平时均可显著提高鹅回肠细菌多样性指数。在十二指肠中,可显著增加乳杆菌属(Lactobacillus)、片球菌属(Pediococcus)、瘤胃球菌属(Ruminococcus)和厌氧螺菌属(Anaerobiospirillum)的丰度,降低假单孢杆菌属(Pseudomonas)、埃希氏菌属(Escherichia)、叶杆菌属(Phyllobacterium)、红球菌属(Rhodococcus)、链球菌属(Streptococcus)、不动杆菌属(Acinetobacter)和希瓦氏菌属(Shewanella)的丰度;在空肠中,可显著降低螺杆菌属(Helicobacter)、寡养单胞菌(Stenotrophomonas)和短波单胞菌属(Brevundimonas)的丰度,增加Swaminathania丰度;在回肠中,可显著增加乳杆菌属(Lactobacillus)、梭菌属(Clostridium)、瘤胃球菌属(Ruminococcus)和假诺卡氏菌(Pseudonocardia)的丰度,降低肠球菌(Enterococcus)丰度;在盲肠中,提高纤维水平可显著增加普雷沃菌属(Prevotella)、螺杆菌属(Helicobacter)和Mucispirillum丰度,降低甲烷短杆菌属(Methanobrevibacter)丰度。3、日粮纤维源对鹅肠道菌群结构有影响,苜蓿组回肠中细菌多样性指数显著高于玉米秸秆组;十二指肠、空肠和盲肠中丰度大于0.01%的细菌门类数量均显著低于玉米秸秆组。表明以苜蓿为纤维源的日粮可显著增加鹅肠道细菌种类。4、从鹅肠道样品中分离出纤维分解菌29株,其中需氧菌19株、厌氧菌10株。经鉴定,8株纤维分解能力较强的菌株分别为胶质类芽孢杆菌、枯草芽孢杆菌、梭状芽孢杆菌、地衣芽孢杆菌、蜡样芽孢杆菌、解纤维梭菌、溶血性葡萄球菌、绿脓假单胞菌;蜡样芽孢杆菌与绿脓假单胞菌为产纤维素酶的最优组合。
[Abstract]:Geese belong to poultry, but digestible and utilization of high fiber diets are important for the exploitation and utilization of crude feed resources for geese to reveal the mechanism of digesting crude fiber. In this study, molecular microecology, animal nutrition and biology were used to study the response of intestinal microflora to diets with different fiber sources and fiber levels, and cellulose decomposing bacteria and their optimized combinations were isolated and screened. It provides a reference for revealing the mechanism of digesting and utilizing dietary fiber in geese. 180 healthy 35 day old Carlos geese (male and female) were randomly divided into 4 groups, 45 in each group with 3 repeats in each group, fed with 5% and 8% fiber levels of corn straw and alfalfa, respectively. The feeding period was 42 days. Nutrient digestibility, intestinal digestive enzyme activity, blood biochemical index and intestinal microflora structure were determined by digestion and metabolism test, slaughter test and MiSeq PE300 sequencing platform. The results showed that the digestibility of NDF and ADF, thymus index, bursa of Fabricius index and spleen index, and the activities of cellulase and trypsin in ileum and cecum could be increased by increasing dietary fiber level. There was no significant effect on CP metabolism rate. There were significant differences in digestibility of NDF and ADF between different fiber sources and fiber level diets. When fiber level was 5, trypsin activity and alkaline phosphatase level in straw group were significantly higher than that in alfalfa group, but thymus index was lower than that in alfalfa group, and thymus index and cellulase activity in jejunum were significantly lower in alfalfa group than in straw group when fiber level was 8. The activity of cellulase in ileum and cecum was significantly higher than that in straw group. In the duodenum, the abundance of Lactobacillus, Pediococcus, Ruminococcus and (Anaerobiospirillum) were significantly increased. To reduce the abundance of Pseudomonas, Escherichia, Phyllobacterium, Rhodococcus, Streptococcus, Acinetobacter (Acinetobacter) and Shewanella. The abundance of Helicobacter, Stenotrophomonas and Brevundimonas was significantly decreased and Swaminathania was increased, and the abundance of Lactobacillus, Clostridium, Ruminococcus and Pseudonocardia was significantly increased in ileum. Reducing the abundance of Enterococcus, increasing the fiber level in the caecum significantly increased the abundance of Prevotella, Helicobacter and Mucispirillum, and reduced the abundance of Methanobrevibacter. The bacterial diversity index in ileum of alfalfa group was significantly higher than that of corn straw group, and the number of bacteria in duodenum, jejunum and cecum with abundance greater than 0.01% was significantly lower than that in corn straw group. The results showed that alfalfa diet could significantly increase the number of intestinal bacteria. 29 strains of fibronectomytic bacteria were isolated from the samples of goose intestines, including 19 strains of aerobic bacteria and 10 strains of anaerobic bacteria. Eight strains with strong fiber decomposing ability were identified as Bacillus glia, Bacillus subtilis, Clostridium clostridium, Bacillus licheniformis, Bacillus cereus, Clostridium fibrillolyticus, Staphylococcus haemolyticus, Pseudomonas aeruginosa. Bacillus cereus and Pseudomonas aeruginosa were the best combination of cellulase production.
【学位授予单位】：吉林农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S835

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