Effects Of Gut Microbiota On Growth Traits Of Two Indigenous Pigs In China

Bamaxiang and Erhualian are Chinese indigenous pig breeds,which have good meat quality,but a slow growth speed.As the growth traits are directly related to the pig industry’s economic benefits,it is an economically important traits.Pigs’ growth is influenced by genetics,feed and environment.The gut microbiome participates in the digestion,absorption and transformation of the host feed and plays pivotal roles in the health,metabolism,immunity and development of pigs.Understanding the relationship between gut microbiome and host physiology has become very important for improving porcine growth traits.However,the correlation between gut microbiome and growth traits of Bamaxiang and Erhualian pigs remains unexplored.In this study,we investigated the gut microbiome of fecal samples of Bamaxiang pigs and cecal content samples of Erhualian pigs and,uncovered the relationship between the gut microbiome and body weight,average daily gain(ADG)via high throughput sequencing of V4 hypervariable region of 16 S r RNA gene.A total of 15,047,236 and9,298,944 tags were obtained from 16 S r RNA gene sequencing for Bamaxiang pigs’ fecal samples and Erhualian pigs’ cecal content samples,respectively.The results indicated that there were significant differences in microbial diversity and community composition between fecal samples and cecal content samples.We identified 45 ASVs and 15 KEGG pathways that were significantly associated with body weight and ADG.ASVs annotation suggested that the bacteria producing butyrate and short-chain fatty acids and belonging to the family Lachnospiraceae,Peptococcaceae and the order Oscillospirales were positively associated with body weight and ADG.Conversely,WCHB1-41,Christensenellaceae＿R-7＿group and opportunistic pathogens were negatively associated with body weight and ADG.KEGG pathways correlated with the Metabolism of Terpenoids and Polyketides,Metabolism of Cofactors and Vitamins showed positive correlations with body weight and ADG,while those pathways correlated with Infectious Diseases exhibited negative correlations with body weight and ADG.Spearman correlation analysis suggested that the changes of gut microbiome lead to the shifts of functional capacities of metagenome and was associated with pig growth.In addition,our results suggested that 2.588% of the phenotypic variation in body weight and 1.923% of the phenotypic variation in average daily gain could be explained by the gut microbiome.Based on these results,the composition of gut microbiome of Bamaxiang and Erhualian pigs will be understood,and provide insights into host-microbe interactions occurring in the pig intestine and will be useful in establishing a strategy for improving growth traits by regulating the gut microbiome composition in the pig.