Swine

Association of Natural Variation in the CD163 and CD169 Genes With Disease Resilience of Grow-Finish Pigs

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Abstract

As the demand for efficient and sustainable global pork production increases, selecting for disease resilience, i.e. an animal's ability to maintain production performance under disease, has gained traction. Central to this strategy is understanding the genetic mechanisms that confer resilience, including the role of genes such as CD163 and CD169. CD163, in particular, has been identified as a receptor for the Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) to enter macrophages, making it a key gene for resistance to that virus. Thus, the objectives of this study were to (1) evaluate linkage disequilibrium among naturally occurring single nucleotide polymorphisms (SNPs) in the CD163 and CD169 genes, (2) investigate the association of these SNPs with disease resilience in a natural polymicrobial disease challenge (NDC), and (3) estimate the interaction effects of these SNPs with genotype for the WUR SNP (linked to GBP5 that was previously associated with response to PRRSV. The data used were generated in a grow-to-finish NDC model, in which, sequential batches of 60 or 75 healthy Landrace x Large White barrows from one of seven breeding companies of PigGen Canada were entered into a nursery/finisher that maintained multiple pathogens using continuous flow. All 3,205 pigs were genotyped using the 650K SNP chip and additionally for specific SNPs within the CD163 (19 SNPs) and CD169 (4 SNPs) genes. Performance and disease resilience phenotypes were also available for all these pigs. Associations of the genotyped candidate gene SNPs with resilience phenotypes were estimated using GBLUP in ASReml 4.2, with fixed effects of batch and SNP*WUR*Company, the covariate of entry age, and random effects of pen by batch, litter, and additive genetics with genomic relationships. LD analysis revealed several SNPs in CD163 to be in complete LD, whereas LD was moderate between SNPs in CD169. Association analyses for CD163 revealed the minor allele at one SNP and the major allele at another SNP to be favorably associated with higher growth and lower mortality. The minor allele at one SNP in CD169 also tended to be associated with higher growth and lower treatment and mortality rates. LD patterns differed between companies, resulting in company-specific interactions of SNPs with performance and disease resilience phenotypes. Interaction effects between these SNPs and WUR genotype by company also revealed certain genotype combinations to be favorable for higher growth and lower mortality. In summary, our findings show that natural variation in the CD163 and CD169 genes is associated with disease resilience. Based on their low minor allele frequencies and favorable associations with resilience phenotypes, pig breeders can take advantage of SNPs in these genes to enhance disease resilience in breeding programs. This project was supported by Genome Canada, Genome Alberta, PigGen Canada, and USDA-NIFA grant #2017-67007-26144.

Keywords: 2026

How to Cite:

Bhatia, V., Fortin, F., Harding, J., Dyck, M. & Plastow, G., (2026) “Association of Natural Variation in the CD163 and CD169 Genes With Disease Resilience of Grow-Finish Pigs”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2285019. doi: https://doi.org/10.31274/wcgalp.23625

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