Beef cattle

Use of research herds to assess industry genetic evaluations of beef cattle

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Abstract

Genetic evaluation programs for beef cattle are well established worldwide; resulting predictions led to dramatic progress in genetic selection over the last 50 years. However, these genetic evaluations rely on data from cooperating producer herds which may have differing levels of precision and accuracy in trait measurement and different levels of trait variation within individual herds, both of which may lead to more or less variation in predicted EBV relative to actual trait expression. Our objective was to detect whether evaluations within breeds were biased using data from a research herd, the germplasm evaluation program (GPE) at the US Meat Animal Research Center. The GPE program sampled industry bulls from prominent US breeds (currently 18) and records production and novel traits on a large proportion of the resulting descendants of these bulls. Traits evaluated for this project were birth, weaning, and yearling weight, maternal weaning weight, carcass weight, marbling score, backfat thickness, and ribeye area on descendants of over 1,200 bulls. We evaluated as the regression of animal performance on sire EPD (Expected Progeny Differences, half of EBV). This regression is expected to be 1; values higher than 1 indicated EPD explained less than full trait variation whereas values lower than 1 indicated EPD explained more full traits. Current bull EPD were obtained for each bull. Bulls with EPD were removed from the pedigree. Covariates of bull EPD were fitted in an animal model where EPD were used directly for first generation progeny of bulls and bull EPD were half in subsequent generations. Thus, the resulting solutions reflected progeny performance regressions on bull EPD. The EPD covariates were fitted across breed or interacting within breed of EPD origin to look at overall and within breed bias. Resulting regressions across breed were 1.32, 0.94, 0.98, 1.22, 1.02, 0.93, 1.22, and 1.23 for birth, weaning, and yearling weight, maternal weaning weight, carcass weight, marbling score, backfat thickness, and ribeye area, respectively. Within breed regression solutions were much more variable and ranged from lows of 0.5 to highs of 3.7 across all traits indicating differences in EPD variation relative to GPE phenotypic variation. Possible reasons for deviations from 1 were that most carcass data in genetic evaluations was from ultrasound records on seedstock animals (vs. GPE actual carcass data), GPE has been based primarily on steers while NCE is based primarily on bulls, and animals were weaned earlier in GPE than in most seedstock herds. Research programs can identify and help to improve genetic evaluations. The USDA is an equal opportunity provider and employer.

Keywords: 2026

How to Cite:

Kuehn, L., Thallman, M., Engle, B. & Snelling, W., (2026) “Use of research herds to assess industry genetic evaluations of beef cattle”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2294335. doi: https://doi.org/10.31274/wcgalp.24319

Rights: 1