Economic values for carcase traits in UK commercial beef cattle

The economic importance of carcase weight, carcase conformation score and carcase fat score, when making selection decisions for terminal beef sires in the UK, is quantified. A framework based on asset replacement theory is first described for the estimation of economic weights for meat production and slaughter traits. A biological growth model that describes growth, conformation and fatness in the carcase over time is used within the economic framework to establish a profit-maximising slaughter point. The economic values, computed by comparing optimum profit per animal before and after genetic improvement of each trait, varied with the crossbreed and production system modelled. Carcase weight economic values were most robust, ranging between 1.88 and 2.31 £ kg^-1. Carcase conformation score economic values ranged between 2.11 and 5.33 £ pt^-1 with the highest values occurring in situations where conformation was relatively poor at the optimal slaughter time. Economic values for reductions in carcase fat score were low (≤ 1.30 £ pt^-1) for bulls in intensive production systems, but potentially much higher (> 5 £ pt^-1) for steers and heifers of British crossbreeds in 16- and 24-month systems without immediate replacement of animals in the finishing facilities. Economic values are also shown to be sensitive to changes in the food price and carcase price penalties.