Changes in gut microbiome associated with parity in sows using full-length 16S rRNA amplicon sequencing

Neonatal piglets exhibit considerable variability in health status, immune response, and susceptibility to infections and vaccinations.Emerging evidence suggests that sow parity significantly influences piglet health, with second-and third-parity sows producing offspring with greater stability in health compared to first-or higher-parity sows.The gut microbiome plays a fundamental role in host health, co-evolving with the host and contributing to offspring development through vertical microbial transmission.Given the potential influence of maternal microbiota on neonatal outcomes, this study aimed to investigate parity-associated differences in the gut microbiome of sows and their potential implications for both maternal and piglet health.Fecal samples were collected from 25 sows representing different parity groups (parity 1, 2, 3, 4, and 8) and subjected to full-length 16s rRNA gene sequencing using the PacBio Sequel II platform.The analysis revealed significant differences in microbiome composition between low parity (parity 12) and high-parity (parity 38) sows.Notably, the relative abundance of Tenericutes declined with increasing parity (P<0.01).Lowparity sows exhibited greater species richness and evenness, with an enrichment of Rhodospirillaceae (LARJ_g), Subdoligranulum, Butyrivibrio_g1_uc, Sharpea azabuensis, and Dialister succinatiphilus, bacterial taxa that may support fetal development and immune function.These findings suggest that low-parity sows harbor a more diverse and potentially beneficial gut microbiome, which could influence piglet health.Furthermore, the use of PacBio full-length 16s rRNA sequencing provided high resolution taxonomic classification, demonstrating the value of long-read sequencing in microbiome research.This study offers new insights into parity-associated microbial shifts and their relevance to swine health management.