Host genetics predominates over gut microbiota in serum copper levels in boars.
Copper is an essential trace element in numerous biological processes; maintaining its homeostasis is crucial for pig health and productivity. In this study, we employed a mixed-effects model to investigate the contributions of host genetics, gut microbiota, and their interactions with serum copper levels in pigs. We further explored potential candidate genes and microbiota associated with copper metabolism. The results demonstrated that host genetics exert a dominant influence on serum copper regulation compared to the effects of the gut microbiota. Furthermore, genome-wide association analysis identified 4 candidate genes, CPHL1, CP, NCEH1, and PDE10A, strongly linked to copper metabolism. By applying multiple association approaches, 10 bacterial genera, such as Blautia, Lachnospiraceae UCG-008, and Ruminococcaceae UCG-007 were found to be significantly correlated with serum copper levels. This research offers novel insights into the genetic and microbial determinants of copper variation in pigs, establishing a foundation for future genetic and microbiota-based strategies aimed at enhancing copper homeostasis and overall livestock health.