Bacterial profiles of the oral, vaginal, and rectal mucosa and colostrum of periparturient sows

The commensal microbiota influences the health, feeding efficiency, and reproductive performance of sows. The microbiota composition in the alimentary and genitourinary tracts and in colostrum/milk during pregnancy and lactation also impacts the developing microbiota and immune system of the piglets and subsequently their growth and health. Knowledge of the microbial compositions is important for evaluation of these effects and for discovering ways to improve the health and productivity of the sows.

Oral, vaginal, and rectal mucosa were sampled from 32 sows of variable parity in late pregnancy on four commercial piglet-producing farms in Finland. Colostrum samples were taken within 6 hours of delivery of the first piglet. Microbial compositions were analyzed by 16S rRNA gene amplicon sequencing. Moderate differences in diversity and composition were observed between farms. The most abundant genera of the oral microbiota were Rothia , Moraxella , and Streptococcus. The rectal microbiota was dominated by Clostridium sensu stricto 1. Streptococcus was the most abundant genus in the vagina and colostrum. Differences in relative abundances of genera were detected between primiparous and multiparous sows. Some of these differences were detected across all the farms; in the multiparous sows, the relative abundances of Fusobacterium and Neisseria were lower in oral samples. Clostridium sensu stricto 1 , Romboutsia , and Lachnospiraceae_UCG_007 were higher and Prevotella lower in rectal samples, and Streptococcus higher in colostrum samples. In vaginal samples, approximately half of the multiparous sows had significantly higher relative abundances of the genera Fusobacterium and Streptococcus than the primiparous sows. Among the differentially abundant taxa, F. necrophorum and F. nucleatum were identified in oral samples, Fusobacterium gastrosuis and Fusobacterium necrophorum in vaginal samples, and Streptococcus dysgalactiae in colostrum samples. Most of the differences were due to unidentified species within the respective genus.

This study provides a comprehensive overview of the mucosal and colostrum microbiota of periparturient sows during normal production conditions on Finnish commercial farms, including potentially interesting differences in the relative abundances of several genera at different mucosal sites between sows of low and high parity.