Comparative Research on Breeding Value Prediction for Calving Score in Beef Breed Cattle

The aim of this study was to compare results obtained using threshold model and individual animal model in calving score genetic evaluation of Charolaise cattle population and election of the best method. The data consists in records of 2935 calving scores recorded. The pedigree covered 6022 animals: 2935 calves, 194 bulls and 2893 dams from Romanian Beef Cattle Breeding Association. The genetic parameters were estimated with threshold and individual animal models. The Spearman’s correlation shows the degree of agreement between the ranking of the same individuals for breeding values using both models. The mean for calving score was 1.35± 0.010. The breeding values for calving score ranged between -0.2749 and 0.3606 with threshold model and between -0.099 and 0.144 with individual animal model. The relative breeding values for the best cattle ranged between 126 and 131 with threshold model and between 125 and 129 with individual animal model. The Spearman’s rank correlation was very high 0.9. The heritability for calving score was 0.139 using threshold model and 0.079 individual animal model. The threshold model is the fittest model for calving ease genetic evaluation in Charolaise beef population but both models can be used successfully.