Ocena genetskih parametrov za lastnosti rasti v populaciji slovenskega mesnega goveda

This study compared genetic parameter es-timates and correlations between estimated breeding values (EBVs) obtained using four single-trait animal models differ-ing in the definition of the common herd-time environmental effect. Analyses were based on field performance records for birth weight (BW), weight at 90 days (W90), and weight at 210 days (W210) in Charolais and Limousin calves born in Slo-venian suckler herds between 1990 and 2017. Model variants defined contemporary groups by herd only (H), or by herd combined with one-year (HY), two-year (HY2), or five-year (HY5) time periods. Heritability estimates varied across mod-els: for BW, direct h² ranged from 0.25 to 0.39, for W90 from 0.11 to 0.37, and for W210 from 0.34 to 0.57. Correspond-ing maternal h² ranged from 0.10 to 0.13 (BW), 0.12 to 0.18 (W90), and 0.20 to 0.29 (W210). The proportion of variance due to common herd-time effects ranged from 0.25 to 0.44, and EBV correlations between models ranged from 0.61 to 0.95. The HY2 model provided the most balanced partition-ing of phenotypic variance across traits and herds, providing the most practical solution for national genetic evaluations under the current data structure.