Abstract: 【Objective】 Modern ecological pig farming techniques differ from traditional techniques.This study was aimed to analyze the bacterial composition of feces from pigs that underwent a transition to an ecological pig farming model,focus on changes in species diversity and community structure,in order to investigate the effects of modern ecological pig farming techniques on the gut microbiota of pigs.【Method】 Eight fattening pigs with similar body weights were selected from a traditional pig farm and transferred to an ecological pig farm for breeding.Fecal samples were collected every 10 days until the pigs reached the age of slaughter.16S rDNA high-throughput sequencing was performed on mixed fecal samples from each time period,and the sequencing data was analyzed using bioinformatics software.The microbiota was annotated based on operational taxonomic units (OTUs) of microbial 16S rDNA gene sequences in order to analyze the changes in species diversity and community structure.【Result】 The bacterial community structure of pig feces changed after being transferred from a traditional pig farm to an ecological pig farm,with an increase in diversity and richness during the breeding period.Proteobacteria,Bacteroidetes,etc.were the dominant phyla,uncultured bacteria,Moheibacter,etc.were dominant genera.The abundance of common pathogenic bacteria such as Elizabethkingia,Escherichia-Shigella,and Corynebacterium decreased to lower levels in feces before slaughter,but bacteria that helped with intestinal digestion,such as Lactobacillus,Treponema and Clostridium,increased in abundance.【Conclusion】 The bacterial community structure of the pig population changed significantly under modern ecological pig farming techniques,forming a unique dominant bacterial community that differs from that of common pig farms.

Key words: ecological pig farm; 16S rDNA sequencing; feces; bacterial community