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 the Charolais breed in the Czech Republic in the years 1992-1997 (4 362 production records with pedigree information) were evaluated by the animal model. Effects of herd-year-season (HYS), age of dam, sex of calf, breed composition (if crossbred), direct genetic effect (DGE), maternal effect (ME), and dam permanent environment (MPE) on birth weight (BW) and weight at 120 days of age (GW) were investigated. HYS was the most significant factor, which covered 64% of variability for BW and 47% for GW. Systematic environmental effects covered 72% of variability for BW and 52% for GW. Residual variation for BW, depending on the selected model, was approximately 7 kg and its ratios to other random effects were 0.4 (HYS - if random), 10 (MPE), 2 (ME), 1 (DGE) and -5 (covariance ME×DGE). Corresponding data for (GW) were 270 kg with ratios of 1 (HYS), 3.5 (MPE), 3 (ME), 2 (DGE) and -6 (ME×DGE). The standard deviation in BW for observations (records) was 6.64 kg, random residual from the selected animal model was 2.12, DGE 0.68, ME 0.55 and MPE 0.66 kg. The respective values of the same parameters for GW were 28.80, 11.70, 3.95, 2.98 and 3.75 kg. The reliability of breeding values corresponded 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 were 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 was r=0.22.