L'optimisation des programmes de sélection

Abstract

The aim of a breeding scheme is to generate livestock improvement in future generations in order to fulfill the future needs of the human population in terms of alimentation, environment and society. In this review, pioneer works conducted between the 1970s and the 1990s are summarized in terms of technical and economic optimization of breeding schemes. Now, it is time to increase both the number of traits considered in breeding goals and the predictive value of selection criteria and estimated breeding values to allow the best choice of reproducers among candidates for selection at the youngest age. For these purpose, genomic selection is a true revolution in population genetic management that arose in the first decade of the 21st century. The design of breeding schemes must be deeply revisited: the pursute of classical reasoning, i.e. the large diffusion of a small number of elite reproducers is extremely dangerous in terms of sensible maintenance of genetic diversity among animal populations, especially when generation intervals are reduced at the same time as that which is currently happening in cattle breeding with the abandon of progeny testing. Furthermore, breeding objectives must be adapted to account for new traits as soon as they are evaluated. This point is critical when unfavorable trends are observed for functional traits and genetics has to integrate a large diversity of production systems to answer to society's demands.