Fig. 1

Comparison of the diversity of gut microbiota and identification of gut bacterial species showing differential abundances between normal and non-return sows. A Comparison of the α-diversity of gut microbiota. B Comparison of the gut microbial composition between normal return and non-return sows by principal coordinate analysis (PCoA) based on the Bray–Curtis distance. C Boxplot of the Bray–Curtis dissimilarity of gut microbiota between subjects within and between each group. Comparison was performed by Wilcoxon rank-sum test at the significance level of P < 0.05. D Differential bacterial species between normal return and non-return sows with metagenomic sequencing data. The significance threshold was set at LDA score > 2 and P < 0.05