Selection index for bulls of Holstein cattle in the Czech Republic

Complex selection indexes are proposed for bulls of Holstein cattle in the Czech Republic. Partial breeding values for milk performance, fertility and body conformation are combined in the index. Conformation is expressed either by linear classification or by general characteristics and body measurements. Variants according to the traits included in breeding objective and in performance recording were tested - breeding objective comprised milk, meat, milkability, health, reproduction, longevity; production traits and linear classification of body conformation or production traits and general characteristics of body conformation and/or production traits, and general characteristics of body conformation and body measurements were used as source of information (in performance recording). For practical use is recommended the variant of reduced selection index where milkability, health and meat performance were left out from breeding objective, and production traits and linear classification of body conformation were employed as a source of information. The index guarantees 69.30% reliability of breeding value estimate and the ratio of selection effects for milk, meat and secondary traits 78 : 8 : 14. The respective importance of milk performance in total (breeding values for milk and components) of reproduction and linear body classification as sources of information in the index are 79.61%, 15.52% and 4.86%.