BREEDING VALUE EVALUATION OF HOLSTEIN-FRIESIAN BULLS BASED ON THE IFORMATION FROM THEIR PROGENY

T. Ivanova, I. Sabeva

Abstract: The aim of the study was to conduct an evaluation of the breeding value of the bulls from the Holstein- Friesian breed on the basis of the information from their progeny. The study assigned 43 Holstein-Friesian bulls belonging to four genealogical lines and siring 246 cows with performance records within the period 1991-2001. Subject of study were the lifetime productive and reproductive traits: milk yield, butter yield, protein yield, productive life, calving interval, as well as the trait age at first calving. Productive life was estimated as the period between date of first calving and date of culling. The breeding value was estimated by the statistical procedure BLUP applying different operational models with regard to the specificity of each of the analyzed traits. It was established that the variance of the studied traits was significantly affected by the factors year of birth and parity, but not by lineage. Statistically significant were estimated to be the regression effects of productive life on lifetime productive traits and that of lifetime milk yield on productive life and lifetime calving interval. The highest breeding value for lifetime milk yield belongs to bull Elut, for butter yield – to Bellamy, for protein yield and calving interval – to Transformer, for productive life – to Starlit, and for age at first calving – to Royalty. The overall all-trait genetic superiority is greatest for the sires from the genealogical lines of the bulls P.F.A. Chiif and Star.

Keywords: BLUP; breeding value; bulls; lifetime traits

Date published: 2017-03-15