Gut microbial diversity among Yorkshire, Landrace and Duroc boars and its impact on semen quality

The gut microbiota plays an important role in pig health and performance, particularly in host growth and fecundity. In present study, the characteristics and diversity of gut microbiota in fine purebred boars from three-way crossbred "Duroc×Landrace×Yorkshire" pigs were investigated using 16 S rRNA gene sequencing. The results showed that the three breeds of boars shared similar gut microbiota, yet there remain slight differences at the family/genus level. At the family level, Ruminococcaceae, Streptococcaceae and Lactobacillaceae have the highest abundance in Landrace, while Rikenellaceae and f_p_251_o5 have the highest abundance in Duroc. The abundance of Prevotellaceae, Lachnospiraceae and Spirochaetaceae in intestinal of Yorkshire were higher than that of Landrace and Duroc. In addition, ten and six biomarkers were identified in the microbiota across breeds and months of age, respectively. Moreover, we evaluated the effect of gut microbiota on boar semen quality, revealing that Duroc had the strongest sperm vitality, significantly associated with the genus Rikenellaceae_PC9_gut_group. In addition, the spermatogenesis ability and sperm production improved gradually along with increase of age. In conclusion, this study provides a reference for understanding the gut microbiota composition of purebred boars used for three-way crosses and their impact on semen performance.