Results of using servicing bulls of the Reflection Sovering 198998 line in a black-and-white cow population

One of the methods in classifying the breeding material of cattle breeds is line breeding. The aim of the research is to evaluate the servicing bulls of the Reflection Sovering 198998 line in a black-and-white cow population according to their breeding and productive characteristics using the «daughter-peer» method. The research material is presented by the data on 3811 breeding cows and 83 servicing bulls used in the black- and-white cattle population of the Vologda region. As a result of studying the breeding value of servicing bulls of the Reflection Sovering 198998 line, the maximum milk yield has been established in the following bulls: Intendant-M 831337 (10743 kg), Mishret 106070030 (10356 kg), Juror 7783 (10096 kg), Omar-M 467825668 (10067 kg). The highest fat content in milk has been found in the daughters of the following bulls: Araks 2700 (4.29%), Baguette 284 (4.26%), Fox 340933203938 (4.25%), Balisto 70625988 (4.14%). The maximum values of the protein mass fraction have been found in the daughters of the following bulls: Milord 417 (3.49%), Alta Remand 3014563630 (3.47%), Omar-M 467825668 (3.46%), Ashanti 71703261 (3.46%), Balisto 70625988 (3.46%). These servicing bulls and their offspring should be used in further breeding work with the black-and-white cattle population. Classification of servicing bulls used in the popu- lation has made it possible to identify four genealogical branches according to their genealogical affiliation: V. Chief Mark 1773417, T.M. Blackstar 1929410, G.A. Chief 1556373, Valiant 16504144. Their breeding stock has a higher milk productivity compared to the average for the studied livestock, and these branches also include bulls, the offspring of which surpasses their peers in milk yield.