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Population characteristics of daughters of domestic and foreign breeding bulls

The use of foreign-bred bulls leads to changes in the genetic structure of the black-and-white breed population, which affects the level of population characteristics. The study was conducted to study the comparative variability and heritability of productive and reproductive characteristics of daughters of sires of domestic and foreign selection in pedigree livestock 10 250 cows 1st calving modern population of black-motley breed of the Vologda region. The superiority of the offspring of foreign bulls in the average indicators of all the studied traits was established with confidence (P<0,001). There were no significant differences in the level of variability of the characteristics of the descendants of domestic and foreign bulls. According to productive traits, the greatest variability of indicators was established for milk yield for 305 days of the 1st lactation Cv = 17,3 – 17,7%, therefore, selection on this trait will be more effective. The greatest share of the influence of bullsfathers, both domestic and foreign selection, in the total sum of all factors determining the value of traits in the population of the black-and-white breed, is determined by the milk yield of daughters η2 = 0,22 – 0,24, the age of the 1st fruitful insemination and the first calving η2 = 0,24 – 0,25. In further breeding work with the breed, it is necessary to obtain and use domestic producers that exceed the breeding value of foreign bulls.