Contrôle chromosomique des populations animales dŽélevage.

The main objective of the chromosomal control of domestic animal populations is to avoid the reproduction of individuals carrying chromosomal abnormalities. Indeed, these latter are generally responsible for an important decrease of reproductive abilities of carrier animals or of their mates. In France, almost all the analyses (2000/year) are carried out at the UMR INRA-ENVT de Cytogenetique des Populations Animales. They mainly concern the bovine and the porcine species. In bovines, 1000 individuals are controlled per year for the presence/absence of the 1/29 Robertsonian translocation. 90% of them are young bull candidates for use in artificial insemination centers. The estimated frequency of the anomaly is the highest in the Blonde d’Aquitaine breed (10.9%). The use of chromosome banding techniques allowed us to identify several new chromosomal abnormalities in this species. In pigs, 650 analyses are carried out each year. 80% of them concern young animals controlled before reproduction (mainly young purebred boar candidates for use in artificial insemination centers). Two systems aimed at detecting the hypoprolific boars have been designed and are used to complement the population control programme. 24 new chromosomal abnormalities have been identified in our laboratory, including 10 during the last three years.