Optimization of breeding schemes

Abstract

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