Developing a breeding objective for a French purebred beef cattle selection programme

This paper presents a procedure for the development of a breeding objective for a beef cattle breed used in a range of production systems. The five ma in beef cattle production systems in France were first described and then e quations of income and costs as a function of the 25 biological traits to b e genetically improved for breeding and production were established. Econom ic values for individual systems were defined as the first derivative of th e herd profit with respect to these 25 traits while the economic values for the overall breeding objective were taken as the average of economic value s over the five production systems. An application is presented for the Lim ousin breed. Sensitivity of the breeding objective to variation in the econ omic or demographic context was also studied, Breeding traits, especially m aternal effects on weaning weight and calving success, were identified as t he most economically important traits requiring improvement. Relative econo mic values were very robust with respect to variations in system frequencie s and replacement rates. A dramatic change in the market price for beef (-5 0%) increased the relative weighting of carcass quality traits to the detri ment of breeding traits although a smaller change in beef price (-25%) had no significant effect on the relative economic values. (C) 1998 Elsevier Sc ience B.V. All rights reserved.