Dynamics of reproductive qualities of cows depending on the productive longevity

Abstract

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