Beef cattle

Estimates of genetic parameters, heterosis, and breed effects for beef tenderness and marbling.

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Abstract

Beef tenderness and marbling score are indicators of eating quality and consumer satisfaction. In U.S. production systems, carcass marbling is a driver of revenue and although beef producers are not directly incentivized to improve meat tenderness it does influence beef demand. This study aimed to estimate genetic parameters, heterosis, and breed effects for slice shear force (SSF) and marbling score (MRB) in a multibreed beef cattle population. Data from animals with both traits recorded (n=7,625) were analyzed using both univariate and bi-variate models fitted in ASReml 4.2. Fixed effects included population, year-season, sex, and linear covariates of slaughter age, breed proportions, and general heterosis. Random effects included a direct additive genetic effect and a residual. Breed effects indicated differences among breeds for both traits. For SSF, breed differences relative to Angus ranged from −0.24 ± 0.46 kg (red Angus) to 7.23 ± 0.75 kg (Brahman). General heterosis effects were −1.81 (4.72) and -0.49 (0.25) for MRB and SSF, respectively. Heritability estimates from univariate models were 0.30 ± 0.03 for SSF and 0.58 ± 0.03 for MRB, suggesting that both traits would respond favorably to selection. The bivariate model confirmed similar estimates and yielded negative additive genetic (rA = −0.148) and phenotypic (rP = −0.146) correlations between SSF and MRB. This weak, but favorable, relationship indicates that genetic selection to improve SSF would need to rely on direct selection rather than through correlated response from selection on MRB. Both tenderness and marbling exhibit exploitable additive genetic variance, enabling simultaneous genetic improvement. However, a measure of tenderness at processing speeds to enable industry-wide selection for tenderness remains elusive.

Keywords: 2026

How to Cite:

Pastrana, M., Russell, C., Kuehn, L., Snelling, W., Engle, B., Shackleford, S., King, A., Wheeler, T. & Spangler, M., (2026) “Estimates of genetic parameters, heterosis, and breed effects for beef tenderness and marbling.”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2285898. doi: https://doi.org/10.31274/wcgalp.23816

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