Influence of Genetic Factors on the Productive Longevity of Cows

Abstract

The economic efficiency of dairy cattle breeding largely depends on the duration of animals' use. According to the 2018 valuation the average age of cows' culling included 3 or 4 lactations and even less in pedigree farms of the Perm Territory. Therefore, it is necessary to consider the degree of influence of various factors on the productive longevity of animals, developing measures that im-pede the reduction of the terms of cow use. The main objective of the study was to determine the dependence of the duration of economic use of cows on genetic factors. The object of the research was the culled black-and-white cows of the LLC "Niva" of the Chastinsky District of the Perm Ter-ritory. Interline differences in the terms of productive use of cows were established during the study. The animals of S. T. Rokit line were characterized by a longer service life of 3.5 lactations and a maximum lifetime milk yield of 20918 kg of milk, which significantly exceeded the produc-tivity of cows of the same age of M. Chiftein lines by 1043 kg, V. Aydial by 3478 kg (P≥0.999), while inferior in terms of milk yield by 1 day of life and use. On the basis of the results obtained, we recommend to use bulls of domestic breeding in the selecting process whose daughters have a long economic use.