Estimation & Prediction

Validation of commercial genomic predictions for carcass traits in non-pedigreed and non-source-verified beef calves

---

Abstract

Improving carcass performance has been a primary focus of beef cattle producers globally, with genetic selection for terminal traits predominately limited to application within seedstock herds. Although many established genetic evaluations exist to provide genetic predictions on seedstock animals, there are few examples of reliable genetic predictions for carcass improvement in commercial cattle. Therefore, the objective of this study was to evaluate the efficacy of carcass trait predictions in unidentified sire and non-source-verified commercial beef calves, using a commercially available multibreed beef cattle genetic evaluation. Carcass phenotypes and genotypes from 43,514 commercial calves with a known individual identity, but without any known recorded pedigree information, or pre-feedlot management information were used in this study. Calves were sorted and co-mingled up to 3 times in the finishing phase where the minimum, mean, and maximum days on feed (DOF) were 133, 286.4, and 546 days, respectively. Genotypes from the calves were included in the Zoetis INHERIT™ genetic evaluation, where genomic breed composition was estimated, and genomic expected progeny differences (GEPD) were obtained for carcass traits. Animals were, on average, 77.3% British (Black and Red Angus, Hereford, and South Devon), 18.7% Continental (Charolais, Gelbvieh, Limousin, and Simmental), 2.5% Dairy (Brown Swiss, Guernsey, Jersey, and Holstein), and 1.1% Bos Indicus (Brahman and Nellore). Validation of genomic predictions for carcass weight (CW), fat thickness (FAT), ribeye area (REA), and marbling score (MS) were performed. For the validation, carcass phenotypes were adjusted for DOF, contemporary group (defined as shipping date), and for carcass weight, adjusted to a standard fat thickness. Across all carcass traits, genomic-only decile tables, arranged by carcass trait GEPD demonstrated strong and consistent improvements in realized carcass performance. The top versus bottom decile differed by 63 lbs., 0.231 in., 2.22 in2, and 174.45 degrees for adjusted CW, FAT, REA, and MS, respectively. The average change in adjusted observed phenotype between adjacent deciles was 6.99 lbs., 0.026 in, 0.218 in2, and 19.38 degrees for CW, FAT, REA, and MS, respectively. Differences between the observed phenotypic change and the corresponding GEBV value change between adjacent deciles were 1.13 (±1.08) lbs., -0.001 (±0.007) in, -0.029 (±0.044) in2, and 1.66 (±6.31) degrees for CW, FAT, REA, and MS, respectively. These results confirm that genomic predictions can effectively differentiate calves across varying levels. Pearson correlations among adjusted carcass phenotypes and genomic-only predictions were low to moderate at 0.23, 0.31, 0.43, and 0.47 for CW, FAT, REA, and MS, respectively. These results indicate that genomic-only evaluations, in the absence of pedigree and individual performance records, can provide reliable predictions for terminal performance in commercial beef animals. This highlights the utility of genomic testing of commercial beef calves for use in optimized management opportunities in feedlots.

Keywords: 2026

How to Cite:

Giess, L., Sanglard, L., Passafaro, T., Gonzalez-Peña, D., Gordo, D., Di Croce, F., Rubio, Y., Short, T. & Andersen, K., (2026) “Validation of commercial genomic predictions for carcass traits in non-pedigreed and non-source-verified beef calves”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2285631. doi: https://doi.org/10.31274/wcgalp.23760

Rights: 1