The combinational ability of genotypes in terms of reproduction in different climatic zones of the Russian Federation

¹ Federal State Budgetary Educational Institution of Higher Education "Moscow State Academy of Veterinary Medicine and Biotechnology – MVA named after K.I. Scriabin", Moscow, Russia
² Russian State Agrarian University – Moscow Agricultural Academy named after K.A. Timiryazev, Moscow, Russia

^* Corresponding author: o.m.muhtarova@yandex.ru

Abstract

This article presents the results of a study of the reproductive characteristics of Holstein cattle bred in four different climatic zones of the Russian Federation: subtropical, temperate continental, sharply continental, and Arctic. The study analyzed a sample of more than 14 thousand first-calf heifers. The main purpose of the work was to study the combinational ability of various lines of the Holstein breed according to key reproduction indicators, such as the age of the first calving, the calving period, the service period, the indifference period, the duration of pregnancy, the coefficient of reproductive ability, the Doha index, and the insemination index. The results of the study showed that the most favorable reproduction indicators were obtained in the III (sharply continental) and IV (Arctic) climatic zones using combinations of lines of bulls and cows V.B.A. x R.S. and R.S. x V.B.A. In general, the state of livestock reproduction in the studied regions is at a good level, as evidenced by the optimal values of the coefficient of reproductive ability, the Doha index and the insemination index. These data emphasize the importance of considering epigenetic factors and phenotypic expression of genotypes in various climatic conditions for the effective use of the genetic potential of Holstein cattle in different regions of Russia.