Definition of the overall udder score for the Czech Fleckvieh Cattle

Abstract

Based on the linear type classification of 49 246 young cows of the Czech Fleckvieh breed the overall udder score was proposed. Calculation of the overall udder score is derived from the particular type traits, especially from those traits, where the optimal development is not scored by maximum. Cubic regression coefficients were used for recalculation and obtained a new scale for traits such as udder depth, teat length, teat thickness, teat position and teat placement. These re-calculated traits together with other particular traits described on the udder were combined to the model for overall udder score – model 1. In the model 2 the same proportion of the particular traits was used with restriction by extreme development of the udder dept, where two different levels of penalization (−3 and −6 points) were used. Both models were compared with the current used system, where the x = 77.1, s = 5.22; for model 1 x = 84.94 (s = 2.65); for model 2 x = 84.40, s = 2.74. In both proposed models the distribution of the overall score for udder showed significantly smooth distribution, than in current system.The coefficient of correlation between current system and new proposals reached r = 0.799. Estimated breeding values for new models decreased from x = 0.199, s = 0.946 by the current used system, to x = 0.087 for model 1, x = 0.089 for model 2 respectively. Also the variability of the breeding values decreased. Estimated coefficients of heritability also decreased from 0.22 by the current system to 0.15 by the model 1 and 0.15 by the model 2, respectively.

Keywords

• type classification
• Czech Fleckvieh
• overall score
• udder