141 Genomic Selection for Heat Stress Resilience in Pigs: Advancements, Applications, and Challenges

Abstract Heat stress is a critical challenge to swine productivity and welfare that causes economic losses and endangers food security. As temperatures continue to increase in most pig producing regions, the effects of heat stress on pig production will become more apparent. The detrimental effects of postnatal heat stress on pig performance and welfare are well-defined. Furthermore, data on the effects of in utero heat stress in pigs describes lifelong production and welfare deficits that may be transgenerational. Despite its economic implications and transgenerational effects, heat stress mitigation strategies remain underexplored. Genomic selection offers a promising avenue for addressing swine heat stress, targeting resilient swine phenotypes to minimize adverse outcomes. However, challenges persist in integrating thermotolerance traits with traditional performance metrics, as improved thermotolerance is often unfavorably correlated with production traits. Therefore, effective selection strategies require balancing productive efficiency with climatic resilience and animal welfare breeding goals. As climate change continues to intensify the frequency and severity of heat stress, innovative approaches that prioritize resilience and adaptability are needed to safeguard swine productivity and welfare.