Breeding value and variance components estimation for birth and 120 days weight of Charolais cattle with respect to direct and maternal genetic effect

The complete database of Charolais breed in the Czech Republic in the years 1992-1997 (4 362 records of production with pedigree information) with birth weight (BW) and weight at the age of 120 days (GW) is evaluated by the animal model. Effects of a herd-year-season (HYS), age of mother, sex of calf, breed composition (if crossbred), direct genetic effect (DGE), maternal effect (ME), and dam permanent environment (MPE) are considered in the evaluation. HYS is the most significant factor, which covers 64% of variability for BW, and 47% for GW. All systematic environmental effects cover 72% of variability for BW and 52% for GW. Residual variability for BW in dependence on the selected model, is approximately 7 kg and its ratios to other random effects 0.4 (HYS - if random), 10 (MPE), 2 (ME), 1 (DGE) and -5 (covariance ME x DGE). Corresponding data for (GW) are 270 kg and ratios 1 (HYS), 3.5 (MPE), 3 (ME), 2 (DGE) and -6 (ME x DGE). The standard deviation for BW for observations (records) is 6.64 kg, random residuum from the selected animal model 2.12, DGE 0.68, ME 0.55 and MPE 0.66 kg. The respective values of the same parameters for GW are 28.80, 11.70, 3.95, 2.98 and 3.75 kg. The reliability of breeding values corresponds on average with these values: 0.31 (DGE of BW), 0.20 (ME of BW), 0.34 (DGE of GW) and 0.19 (ME of GW). Correlations between the estimated constants for BW and GW are r = 0.33 for DGE, 0.18 for ME, 0.21 for the MPE, and 0.20 for the residual effect of the model. Correlation of corresponding records of body weights is r = 0.22.