EN
The matings and selection of horses for the breeding stock in national Arabian horse studs from the 1947-1948 to 1996-1997 seasons were analysed. The data were examined taking into account the average values of the inbreeding coefficient (F). It was stated that breeders constantly avoided mating highly-related horses. Matings which concluded in abortion exhibited a higher level of inbreeding, while those which were either barren or ended in the death of the foal were characterised by lower average values of the inbreeding coefficient. In the selection of horses for the breeding stock, breeders preferred stallions with lower inbreeding coefficients. Moreover, among the stallions of the same father those with F values below the average were selected (statistically significant regularity). This tendency, however, was not observed in the selection of mares.