INVESTIGATION TO BREEDING VALUE OF FAMILI ES OF MARES AT THE THOROUGHBRED

Breeding values for 399 thoroughbred mares were estimated on basis of the realised handicap (GAG) of their 992 progenies by means of BLUP an imal model. The absolute difference ran to 30.40 kg GAG; 17% of female s got a positive breeding value, 16% a negative one. The mares could b e related to performance ranges between - 1.97 and 3.06 kg. Statistica lly covered positive and negative breeding values were found out for 2 families in each case. Families covering up to 5 generations seem to be of special interst to breedinf practice. Top class horses are a sup porting element for selective decisions.