Objective This experiment was conducted to study the characteristics of fecal microbial diversity and explore the differences in fecal microbiota between easy-conceiving and difficult-conceiving Kazakh horses.

Methods Twenty Kazakh mares with similar age, body weight and parity were selected and divided into 2 groups with 10 horses per group. All experimental horses were fed the same forage and feed, with free access to water.

Results According to OTU clustering analysis, there were 1 118 common OTUs in the feces of the two groups, 246 unique OTUs in the YS group, and 261 unique OTUs in the YC group. At the phylum level, the top three phyla in relative abundance in both YS and YC groups were Firmicutes, Bacteroidota and Proteobacteria. At the family level, the top three families in relative abundance were Moraxellaceae, Planococcaceae and Rikenellaceae. At the genus level, the top three genera in relative abundance were Acinetobacter, Rikenellaceae_RC9_gut_group and Solibacillus.

Conclusion The analysis of fecal microbial diversity between easy-conceiving and difficult-conceiving Kazakh horses provides data support and theoretical basis for revealing the relationship between fecal microbiota and conception performance of Kazakh horses.