PSVI-2 Purebred and crossbred herds: Economic values for fertility, growth, and carcass traits.

Abstract Selecting for a single trait often leads to antagonistic correlations with other important traits. In beef cattle, well-documented trade-offs exist between growth, carcass, and reproductive performance traits. Therefore, implementing an economic selection index offers a strategic approach to achieving simultaneous genetic improvement across multiple traits by weighting them according to their economic value and genetic correlations. Here, economic values were derived for reproduction, growth, and final product quality traits using the UF Purebred Brahman (BRU) and the UF Multibreed Angus-Brahman (MAB) beef cattle herds as the reference populations. Assuming profit maximization as breeding objective, abioeconomic model was developed by leveraging herd management information and financial data (income and expenses) from May 2023 to September 2024. Briefly, BRU and MAB cattle are primarily raised under pasture conditions, with nutritional supplements provided depending on forage availability and for certain animal categories at specific life stages. The resulting offspring of BRU cattle follow one of five pathways: sold at weaning, sold at yearling, retained as replacements, sold at 18 months for slaughter, or sold for breeding purposes. Whereas MAB offspring are managed through one of three pathways: sold at weaning, retained as replacements, or transferred to a partner feedlot operation for later carcass and meat quality evaluation. Economic profit was calculated by subtracting total costs from total revenues. Economic values (EV) were estimated as the partial regression coefficients of trait performance on the profit function. These EV represent the expected change in profitability resulting from a unit change in a specific variable, while holding all other variables constant. The EVs in the BRU herd showed that cow calving success was valued at $1,092.63 per cow, reducing age at first pregnancy resulted in a gain of $40.25 per month, weight at 18 months was valued at $3.76 per kilogram gained, dressing percentage increments were valued at $33.06 per 1% increase, and quality and yield improvements were valued at $7.01 and $8.97 per 100 lb of carcass increase, respectively. The EVs for the MAB herd revealed that early pregnancy in the breeding season was valued at $155.99 per cow, reducing age at first pregnancy was valued at $40 per month, $5.36 per kilogram gained for increased weaning weight, $40.22 per 1% increase for improved dressing percentage, and $5.80 and $5.50 per 100 lb of carcass increase in USDA grading for enhanced quality and yield, respectively. The results highlight significant economic benefits of improving cow calving success, reducing age at first pregnancy, and enhancing growth, carcass, and quality traits in both purebred and crossbred beef cattle herds. These findings can inform data-driven breeding decisions, enabling beef cattle operations to optimize production, enhance profitability, and accelerate genetic progress through multi-trait selection.