As part of the genetic improvement of production, selection of breeds (purebred selection) on the one hand and crossbreeding, exploiting the complementarity between breeds and hybrid vigor or heterosis other hand, are methods choice used by animal husbandry. The pure breeding as practiced in the developed world, based on the individual performance of breeding as well as the placement of the offspring, uses expensive infrastructure and significant human resources. In addition, genetic progress is slow and must be sustained effort. For all these reasons, in the less favored regions of the world, although the intra-breed selection is operational, most stakeholders are most often uses the crossbreeding technique leading to immediate results and protecting local breeds. Thus, in dairy cattle, many countries have used the Holstein, Brown in the Alps, and the Montbéliarde Normande with varying success. In the meat sector, in cattle, swine and sheep, as well as in the area of poultry meat, crossing indigenous breeds with exotic breeds imported leads to interesting results. In the Walloon Region, due to the hard work of breeders, animals have emerged exceptional and, in cattle, swine and sheep, they are in fact, more muscular animals in the world. Thus, bulls Belgian Blue reared under natural conditions, have average daily gains as high as 2000 g / d with yields close to slaughter 70% Pietrain pigs reach values of the performance slaughter of around 83% and the yield values as high as 59% were observed in Texel sheep. All these animals have the characteristic of being very efficient while presenting carcasses with more muscle, less fat and less bone. As for local poultry type Ardennaise, it has remarkable phenotypes leading to immediate traceability (black members), more than 150 eggs per clutch and a darker meat.The author gives in detail examples of the use of crossbreeding with cattle, sheep, pig and poultry all originated from the Walloon Region of Belgium.