GENETIC POTENTIAL AND BREEDING VALUE OF BULL PRODUCERS

The process of improving the breeding and productive qualities of dairy cattle is impossible without the selection of servicing bulls with high genetic potential and breeding value. The paper investigates the breeding value and genetic potential of servicing bulls whose bio-products are used to inseminate dairy cattle in the Republic of Mari El. The author finds out that the population of bulls is of high quality and belongs to five genealogical lines: Vis Back Aydial 1013415, Montwick Chiftein 95679, Sawring Reflex 198998, Seling Trijun Rokita 252803, Pabst Governer 882933. Bulls, obtained from highly productive ancestors and have a high genetic potential in terms of milk yield (from 7513 to 13361 kg) and mass fraction of fat in milk (from 3.87 to 4.43%). The female offsprings of the investigated servicing bulls have rather high level of milk productivity (milk yield is 7017 kg on average, mass fraction of fat is 3,94, protein - 3,08%). The paper highlights that the highest level of dairy productivity was achieved by the descendants of the bull Yasa-M 462771. Their milk yield for the first lactation was 8185 kg, mass fraction of fat was 3.93%, protein concentration was 3.11%. The most part of investigated bulls have high breeding value according to all studied milk productivity parameters. According to the milk yield, it varied from 96.1 to145.5%, the mass fraction of fat – from 100 to 101.8, protein -from 98 to 101.6%. 10 servicing bulls as Artist, Butembo-M, Koldun, Leksaid, Morzhik, Norman-M, Auckland-M, Sayan, Spartak and Yasa-M have relative breeding value on all studied indicators which was above 100%. The most valuable servicing bulls were observed as Yas-M 462771 and Koldun 103.