RELATIONSHIP BETWEEN PEDIGREE VALUE AND T HE RESULTS OF PROGENY TESTING IN BREEDING BULLS OF THE BLACK PIED CATTLE

The investigation involved 350 sires of the Black Pied cattle of inlan d and outland provenance which had been chosen for test mating in the years 1983-1987. In these sires the breeding value (BV) was determined in progeny testing for milk performance (PTM), that means BV and RBV (relative breeding value) for milk amount, fat content in milk and mil k fat amount. In the fathers of bulls we determined their provenance a nd performance of the daughters assessed in PTM. In the mothers of bul ls we investigated average production over all the standardized lactat ions, i.e. kg of milk, fat percentage and kg of milk fat. The effects of the levels of pedigree value of bulls on the estimates of their bre eding value in PTM were analyzed by the multifactor analysis of varian ce using the least-squares method. The effects of the chosen model: ye ars of sires, their provenance, level of production of the daughters o f father in PTM and effect of mother's performance. Interactions of th ese effects were calculated for the purposes of detailed analysis. The effect of the level of sire testing (O) was statistically significant for all BVs (P < 0.05), while the effect of mothers' s performance (M ) on the level of their sons was statistically significant in BV and R BV for milk fat production. The interaction effect (O x M) was assesse d as statistically highly significant for all investigation parameters of the BV of their sons (P < 0.001). The mean values of all parameter s of bulls' BV are increasing with the level of the testing of their f athers. This increase makes +140 kg for milk production of bulls' daug hters, +0.05 % for milk fat content and +6.7 kg for fat production. In the BVs and/or RBVs for milk production this difference makes +288 kg and/or +8.9, +0.13 % and/or 2.5 for milk fat content, and +14 kg and/ or 12.7 for fat production. In the effect of mothers' performance on B V and/or RBV of the bulls the difference between the groups with best and worst assessment according to mothers' performance is +69 kg and/o r +2.4 for milk production, +0.05 % and/or 2.6 for milk fat content an d +6 kg and/or 4.9 for fat production. The mean values of bulls' BVs i ndicate an increase from 1543.8 kg to 165.5 kg for milk fat production of the daughters of assessed bulls within the decisive categories acc ording to the (O x M) level, the estimates of RBV for milk fat product ion have the values from 92.6 to 110. The difference between the group s with best and worst assessment according to (O x M) makes 17.4.