Swine

Investigating Genetic Parameters for Primal Lean and Fat Content using Dual Energy X-Ray Absorptiometry in Crossbred Pigs

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Abstract

Increasing carcass lean yield is one of the key objectives in most swine breeding programs. Additionally, there is growing interest in tailoring selection for individual carcass primals to accommodate regional market preferences and improve carcass profitability. This study estimated genetic parameters for carcass lean yield, as well as lean and fat content of the total carcass and five major primal cuts. Historically, carcass lean yield has been predicted from physical or probe measurements during grading, whereas more recent technologies, such as dual-energy X-ray absorptiometry (DEXA), use image analysis to estimate actual lean, fat, and bone content. A total of 2,464 carcass records were collected from 1,118 female and 1,346 male crossbred pigs produced from Duroc sires and Landrace × Yorkshire F1 dams. Recorded traits included predicted carcass lean yield and DEXA-estimated lean and fat content for the total carcass and five individual primals (loin, belly, butt, picnic, and ham). Genetic parameters were estimated using bivariate single-step GBLUP animal models implemented in WOMBAT, with animal, contemporary group, and litter fitted as random effects. Heritability estimates for carcass lean yield and DEXA lean and fat content traits ranged from 0.27 ± 0.05 to 0.42 ± 0.06. Genetic correlations among DEXA primal traits were strong, ranging from 0.82 ± 0.05 to 0.94 ± 0.02. Predicted carcass lean yield was strongly genetically correlated with total DEXA carcass lean and fat content; however, correlations with individual primal traits were more variable. Genetic correlations between DEXA-estimated primal lean traits and predicted carcass lean yield (0.62 ± 0.09 to 0.83 ± 0.05) were consistently lower than correlations with total DEXA carcass lean (0.91 ± 0.03 to 0.98 ± 0.01). Similarly, genetic correlations between DEXA-estimated primal fat traits and predicted carcass lean yield (−0.82 ± 0.05 to −0.65 ± 0.08) were generally weaker than correlations with total DEXA carcass fat content (0.92 ± 0.02 to 0.98 ± 0.01). Overall, these results demonstrate an opportunity to improve selection for primal-specific lean and fat content by incorporating DEXA computed traits into swine genetic improvement programs.

Keywords: 2026

How to Cite:

Houlahan, K., Juárez, M., Kemp, R., Massender, E. & Plastow, G., (2026) “Investigating Genetic Parameters for Primal Lean and Fat Content using Dual Energy X-Ray Absorptiometry in Crossbred Pigs”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2284313. doi: https://doi.org/10.31274/wcgalp.23563

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