Assessing the value of improved marbling in beef breeding objectives and selection

A method of assessing the economic value of improved marbling for use in deriving beef breeding objectives for individual decision-makers is described and illustrated. Correlations between breeding objectives that account for marbling score were examined for 6 cases that differed in their breeding role, market-addressed (Domestic Australian, high quality Japanese), and other production system characteristics. Under the assumptions considered, the economic value of improved marbling varied with mean marbling score (i.e. was non-linear) in objectives for the Japanese market. Marbling improvement was a more important aim in populations with a greater propensity to marble. Differences between some breeding objectives were large (genetic correlations less than or equal to 0.65), with marked differences (genetic correlations <0.40) between an objective that targeted only feedlot finishing performance for the Japanese market and objectives that targeted complete pasture-fed production for the Domestic Australian market. Varying individual assumptions had only small effects on results. A procedure is described for including marbling evaluations in selection indices where marbling contributes non-linearly to the breeding objective.