Microbiome

Longitudinal Analyses Reveal the Dynamic Interplay of Host Genetics and the Gut Microbiome in Shaping Heat Resilience in Sows

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Abstract

Heat stress (HS) is a growing threat to swine production, compromising animal health and welfare and causing significant economic losses. While improved farm management practices and genetic selection offer sustainable HS mitigation strategies, host genomics alone cannot fully explain the variation in individuals' thermotolerance. The gut microbiome, a critical regulator of host physiology, represents a promising but largely unexplored component of heat resilience in livestock. In this context, the main objectives of this study were to quantify the contributions of the host genome, gut microbiome, and their interaction to vaginal temperature (Tv), a key indicator of HS, in lactating sows. We analyzed longitudinal Tv data using five different models that progressively incorporated host genomic, microbiome, and genotype-by-microbiome (GxM) effects. We estimated variance components including heritability (h2), microbiability (m2), and holobiability(holo2), alongside temporal correlations and predictive ability across time for five different models. Our results show that both host genetics (h2 ranging from 0.134 to 0.398) and the gut microbiota (m2 ranging from 0.135 to 0.278) are significant contributors to the variation in Tv, with the influence of gut microbiota increasing as HS progresses. We identified a credible GxM interaction, indicating that the host genetic potential for thermotolerance is context-dependent on the microbial community. Consequently, the holobiont models, accounting for all components, explained the largest portion of phenotypic variance (holo2 up to 0.535). Furthermore, models integrating both genomic and microbiota data consistently achieved the highest predictive accuracy for Tv, particularly in a stringent cross-environmental validation, indicating they are robust and generalizable. In conclusion, this study provides the first evidence that the gut microbiota are a significant component of heat resilience in lactating sows. Integrating gut microbiota with host genetics could provide a framework for improved prediction of HS, complementing genomic information.

Keywords: 2026

How to Cite:

Wen, H., Tiezzi, F., Jiang, J., Brito, L., Johnson, J., Huang, Y. & Maltecca, C., (2026) “Longitudinal Analyses Reveal the Dynamic Interplay of Host Genetics and the Gut Microbiome in Shaping Heat Resilience in Sows”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2284643. doi: https://doi.org/10.31274/wcgalp.23606

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