Genetic Relationship between Carcass Traits and Carcass Price of Korean Cattle*

The objectives of this study were to estimate genetic parameters for the carcass price and carcass traits contributing to carcass grading and to investigate the influence of each carcass trait on the carcass price using multiple regression and path analyses. Data for carcass traits and carcass prices were collected from March 2003 to January 2009 on steers of Korean cattle raised at private farms. The analytical mixed animal model, including slaughter house-year-month combination, linear and quadratic slaughter age as fixed effects and random animal and residual effects, was used to estimate genetic parameters. The effects of carcass traits on the carcass price were evaluated by applying multiple regression analyses. Heritability estimates of carcass traits were 0.20±0.08 for carcass weight (CWT), 0.33±0.10 for back fat thickness (BFT), 0.07±0.05 for eye-muscle area (EMA) and 0.25±0.10 for marbling score (MS), and those of carcass prices were 0.21±0.10 for auction price per 1 kg of carcass weight (AP) and 0.13±0.07 for total price (CP). Genetic correlation coefficients of AP with CWT and MS were -0.35±0.29 and 0.99±0.04, respectively, and those of CP with CWT and MS were 0.59±0.22 and 0.39±0.29 respectively. If an appropriate adjustment for temporal economic value is available, the moderate heritability estimates of AP and CP might suggest their potential use as the breeding objectives for improving the gross incomes of beef cattle farms. The large genetic correlation estimates of carcass price variables with CWT and MS implied that simultaneous selection for both CWT and MS would be also useful in enhancing income. (