Genealogical structure and evaluation of Holstein breeding bulls

Abstract

The Holstein bulls’ genealogical structure on the Russian Federation breeding enterprises (n= 3 75), as well as the selection types ratio of their breeding, genomic parameters’ assessments in the countries of exporting were studied. The evaluation of 21 breeding sires on their daughters quality and their mothers milk production comparison in the breeding plant’s herd was carried out. A narrow range of genealogical lines of imported Holsteins, that does not allow genetic variability’s effective use at domestic livestock populations improvement, has been identified. These bulls evaluation by the offspring quality revealed the distribution of daughters on milk yield terms and the mass fraction of protein (PC) at the herd improvement, but with the mass fat fraction (FC) decreasing relative to the groups of mothers. The determination of the daughter groups’ repeatability coefficients and ranking based on the milk production characteristics revealed significant differences with the genomic values estimated fortheir fathers: for milk yield rs = 0,395, for PC — rs =0,200, and for FC — rs = – 0,570. The author concludes that it is impossible to plan improvement ofthe main features of breeding in herd at breeding bulls selecting according to the genomic assessment indicators’ levels and givessuggestions for improvment of methodology of evaluating breeding sires by the quality of offspring in dairy cattle breeding of the Russian Federation.