引种仔猪进境及传代后肠道菌群演替发育规律

Succession and development of intestinal flora of imported piglets

我国每年从国外大量引进生猪种质资源,生猪养殖的重引进、轻选育,易陷入“引种-退化-引种”的不良循环。本研究以种猪肠道菌群演替发育规律为核心,分析目前饲养方式和环境因素对肠道菌群的影响,为种猪引进后的饲养管理提供改进依据。以从法国引进的杜洛克、皮特兰、长白断奶仔猪为研究对象,分(35±5)日龄、(280±5)日龄和子代(35±5)日龄3个阶段采集粪便样品,用Illumina Miseq平台对样品微生物组的16S rRNA基因V3~V4区进行分析和比较,阐述种猪肠道菌群演替发育规律,探讨饲养方式和环境因素改变对肠道菌群的影响。结果显示,皮特兰种猪肠道菌群受环境影响大,与进境时(a组)相比,进境后(b组)菌群多样性降低,丰度显著增加,但经过传代后(d组)菌群多样性增加。3个品种进境后(b组)与传代后(d组)菌群结构变化趋势相同:在门水平,厚壁菌门、拟杆菌门丰度增加,变形菌门丰度显著降低;在属水平,仔猪肠道乳杆菌属和不动杆菌属丰度显著降低,链球菌属、普氏菌属、志贺菌属等丰度增加。在功能组成上,进境仔猪在我国经过1次传代后,功能组成上与刚进境时已没有交叉;仔猪视黄醇代谢,细胞色素P450对异生素的代谢极显著下调(P<0.01);氟苯甲酸甲酯降解以及肽聚糖合成功能显著下调(P<0.05)。因此,本研究认为环境条件对仔猪进境后肠道菌群多样性具有显著影响,传代也不能逆转已经产生的变化,环境因素引起仔猪肠道菌群变化是性状退化或不能稳定遗传的因素之一,提示仔猪引种后应加强科学化的饲养管理,注重对仔猪乳杆菌、视黄醇等物质的补充。

Domestic pigs have introduced a large number of germplasm resources from abroad.The pig breeding emphasizing introduction and ignoring selection has fallen into a vicious circle of“introduction-degeneration-introduction”.In this study,fecal samples of Duroc,Pietrain,and Landrace weaned piglets imported from France were collected at three stages.The Illumina Miseq platform was used to analyze and compare the V3-V4 region of the 16 S rRNA gene of the microbiome to elaborate the developmental pattern of intestinal flora succession in breeding pigs,and to explore the effects of changes in feeding methods and environmental factors on intestinal flora.The results showed that the intestinal flora of Pietrain pigs were greatly affected by the environment.Compared with the entry group(group a),the microbiota abundance of the after-entry group(group b)was significantly increased,and the diversity was decreased,but the microbiota diversity of the after-passage group(group d)was increased.The change trend of the microbial community structure of the three breeds was the same in the after-entry group(group b)and the after-passage group(group d).At the phylum level,the abundance of Firmicutes and Bacteroides was increased,and the abundance of Proteobacteria was decreased significantly.At the genus level,the abundance of Lactobacillu s and Acinetobacter in the piglet’s intestines was decreased significantly,and the abundance of Streptococcus,Prevotella,and Shigella was increased.There was no crossover of the functional compositions between the group a and group d.Piglet retinol metabolism and cytochrome P450were significantly down-regulated to the metabolism of xenobiotics(P<0.01).The functions of fluorobenzoate degradation and peptidoglycan synthesis were significantly down-regulated(P<0.05).Therefore,this study revealed that environmental conditions and feeding pattern had a significant impact on the intestinal flora after their introduction into the country.Passages cannot reverse the changes that have occurred.Changes in the intestinal flora of piglets caused by environmental changes were one of the key factors for trait degradation or instability of inheritance,suggesting that scientific feeding management of piglets after their introduction should be strengthened and the supplementation of Lactobacillus,retinol and other substances should be paid attention to.