Disease & heat resistance

Genomic regions associated with resilience indicators and medical treatments in Swiss Large White and Swiss Landrace pigs

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Abstract

Breeding pigs that are resilient to environmental stressors is gaining importance. A key feature is that resilient pigs might require minimal medical treatments. Data from automated feeding stations allow to develop resilience indicators by quantifying deviations from predicted feed intake patterns. Although previous studies have shown that deviations from predicted feeding patterns are heritable, the genetic architecture of these traits remains largely unknown.In this study, feeding station data from the performance testing station of SUISAG were used. Daily records of feed intake, feeding duration and frequency were available for 12,230 Swiss Large White (SLW) and 2,523 Swiss Landrace (SLR) pigs for a uniform age trajectory between 75-155 days. Medical treatment records and pedigree data were also available. A subset of the phenotyped cohort consisting of 2,827 SLW and 1,514 SLR pigs had microarray-derived genotypes, which were imputed to the sequence-level. Resilience was estimated as the ln-transformed variance (lnvar) of differences in observed versus predicted trait values via linear regression for feed intake, feeding duration and frequency. Genetic parameters were estimated per breed using gibbsf90+ software accounting for pen (random), sex and farm of origin (fixed) and the arrival weight and number of daily records (covariate) using single-step GBLUP. Posterior means and 95% highest posterior density (HPD) intervals were obtained from 500,000 samples, a burn-in of 50,000 and thinning interval of 1,000. Genome-wide association studies (GWAS) between imputed sequence variant genotypes and resilience indicators were performed using GCTA-software, accounting for the same effects as described above and the first four principal components calculated from the genomic relationship matrix.Heritability estimates for lnvar of feed intake, feeding duration and frequency were moderate (SLR: 21.3-32.1%; SLW: 18.0-35.8%; Table 1). Heritability for medical treatments was lower (SLR: 11.6%; SLW: 7.4%). Although Pearson correlations were significantly positive between lnvar of feed intake and number of medical treatments (r=0.26 in both breeds), genetic correlation estimates had wide 95% HPD intervals that included zero, indicating considerable uncertainty.GWAS revealed a region on SSC1 in SLW significantly associated with lnvar of feed intake (1:270,760,166, p=2.2x10-12) and feeding duration (1:270,518,583, p=1.1x10-11), near ASS1 and FUBP3. This pleiotropic QTL was associated with mean feed intake, daily gain and lean meat content in earlier studies. GWAS for the number of medical treatments identified a significant region on SSC2 in SLW (2:30,002,033, p=4.8x10-8) near MPPED2, and on SSC3 in SLR (3:2,764,444, p=1.3x10-8) near SDK1, previously linked to pigs' antibody response after PRRSV vaccination. These findings provide new insights into the genetic architecture of resilience in pigs. The moderate heritabilities of resilience indicators support their inclusion in breeding programs. However, the uncertain genetic correlations with medical treatments suggest that selection for resilience alone may not substantially reduce the need for medical interventions.

Keywords: 2026

How to Cite:

Gorssen, W., Kadri, N., Khayatzadeh, N., Winters, C. & Pausch, H., (2026) “Genomic regions associated with resilience indicators and medical treatments in Swiss Large White and Swiss Landrace pigs”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2258928. doi: https://doi.org/10.31274/wcgalp.23392

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