A bio-economic model for calculating economic values of traits for intensive and extensive beef cattle breeds

A deterministic bio-economic model was developed to estimate marginal economic values for production and functional traits for intensive (Continental) and extensive (British) breed groups in their typical production systems, and to estimate the relative importance of these two groups of traits. The model simulates the economic result of one purebred beef suckler cow and her progeny of each breed group on the basis of their lifetime production. The level of performance of the cow and progeny was set to the population means of traits in the respective breed group. Relative economic values (REV, in percentage) were estimated for 14 traits, seven production and seven functional traits. The REV for the intensive and extensive breed groups, respectively, were: herd life of cow; 39 and 29%, age at first calving; 6 and 4%, calving interval; 4 and 3%, calving difficulty; 2 and 3%, carcass weight; 24 and 29%, carcass conformation; 5 and 5%, carcass fatness; 2 and 5%, growth rate from birth to 200 days; 4 and 6%, growth rate from 200 days to 365 days; 6 and 9% and growth rate from 365 days to slaughter; 7 and 7%. The value of stillbirth, twinning frequency, limb and claw disorders and birth weight were all close to zero in both breed groups. Functional traits were almost as important as the production traits for both breed groups; however, functional traits were even more important for the intensive breed group (51 vs. 39%). The results suggest that functional traits are important traits to include, regardless of breed, when developing breeding objectives for beef cattle, and should to a much larger extent than at present, be recorded in breeding schemes for beef cattle.