Dynamics of reproductive qualities of cows depending on the productive longevity

The Ural type of the domestic black-and-white mottled breed features high productivity rates, good suitability for industrial milking technology, but duration its productive longevity is 2.4–2.6 lactations only, although in herds there are cows with up to 10 lactations. decline associated particular reproductive qualities. As a result research, it was found that Sealing Trijun Rockit proved be most resistant their long use within conditions dairy farms milk production pedigree reproducers; 4.0 lactation. In other lines ranged from 1.8 (Pabst Governor line) 2.5 (Montvic Chieftain A low fertility rate (less than 0.95) proves existence reproduction problems herd. Modern Holsteinized cattle bred Sverdlovsk region has breeding potential quite and, despite certain problems, they able produce time ecological and forage zone.