生物发酵稻秸对湖羊消化道上皮形态及微生物区系的影响

Effects of bio-fermented rice straw on the epithelial morphology and microbiota of digestive tract of Hu sheep

摘要:

【目的】本研究旨在通过显微观察和16S rRNA基因高通量测序技术来探究饲喂生物发酵稻秸对湖羊肠道上皮形态及微生物区系的影响。【方法】试验选择70日龄、体重相近(25.15±0.47) kg的湖羊公羔21只，根据饲粮中粗饲料的组成随机分为3组：稻秸组、生物发酵稻秸组和苜蓿干草组，饲粮精粗比为6:4，试验持续7周，其中适应期3周，正试期4周，结束后屠宰取样，采集瘤胃、空肠和结肠上皮组织进行观察测量，收集对应肠段内容物用于微生物区系和代谢产物测定。【结果】与稻秸组相比，饲喂生物发酵稻秸显著提高湖羊瘤胃中纤维杆菌(Fibrobacteres)的相对丰度和挥发性脂肪酸(volatile fatty acids, VFA)的含量，促进瘤胃上皮的发育；显著提高湖羊空肠中厚壁菌门(Firmicutes)和疣微菌门(Verrucomicrobia)的相对丰度，改变空肠微生物菌群结构，促进空肠上皮组织的发育；改变湖羊结肠微生物菌群结构。【结论】饲喂生物发酵稻秸有利于湖羊肠道上皮的发育，并增加消化道内的微生物多样性。

关键词:生物发酵稻秸;湖羊;消化道;微生物区系

Abstract:

[Objective] To investigate the effects of bio-fermented rice straw on intestinal epithelial morphology and microflora of Hu sheep by microscopic observation and 16S rRNA gene high-throughput sequencing technology. [Methods] Twenty-one male lambs aged 70 d with similar body weight (25.15±0.47) kg were randomly divided into three groups based on the composition of dietary roughage, namely, the rice straw group, the bio-fermented rice straw group, and the alfalfa hay group, with dietary concentrate to forage ratio of 6:4. The experiment lasted for 7 weeks, including 3 weeks of the adaptation period and 4 weeks of the experimental period. At the end of the experiment, all animals were sacrificed to collect samples. Epithelial tissues of the rumen, jejunum, and colon were collected for morphological observation. The content of corresponding intestinal segments was collected for the analysis of microbiota and metabolites. [Results] Compared with the rice straw group, the bio-fermented rice straw group significantly increased the relative abundance of Fibrobacteres and the content of volatile fatty acids (VFA) in the rumen of Hu sheep, and promoted the development of the rumen epithelium. The bio-fermented rice straw significantly increased the relative abundance of Firmicutes and Verrucomicrobia in the jejunum of Hu sheep. It changed the structure of the jejunal microbial community and promoted the development of jejunal epithelial tissues. Moreover, the colonic microbial structure of Hu sheep was also changed by the bio-fermented rice straw. [Conclusion] Feeding bio-fermented rice straw is beneficial to the development of intestinal epithelium and increases the microbial diversity in the digestive tract of Hu sheep.

Key words:bio-fermented rice straw;Hu sheep;digestive tract;microbiota