Assessment of the breeding value of Holstein black-and-white stud bulls in the Republic of Kazakhstan

Abstract

Currently, the dairy cow industry's primary goal is to reach maximum indicators in the manufacture of high-quality goods. It is necessary to utilize high-quality animals in breeding and productive qualities to attain this goal. Numerous research and practical works have proven that stud bulls have a major impact on the genetic effect of animal stock correction: proper stud bull selection ensures maximal genetic development in animal production. Animals of the Holstein breed of various selections are used to enhance domestic black-and-white cattle (Canadian, American, Danish, etc.). The article presents the results of the assessment of stud bulls according to the Instructions in force in the Republic of Kazakhstan. As an object of research, information was used on first-calvers (daughters) who lactated in 2016-2017 in the breeding herds of the republican populations of Holstein cattle. In a comparative aspect, the analysis of the results of a study of the breeding qualities of the estimated bulls in the context of different years and in total is carried out. The necessity of applying new approaches to assessing the breeding value of stud bulls in dairy cattle breeding is established.

Productive Traits and Reproductive Capacity of First-Calf Cows at Different Selection Options

“…The analysis of the results obtained for the aggregate estimation period showed that when using information for two adjacent years, firstly, the number of daughters per one estimated bull increases (to 52.4%), and secondly, the average number of effective daughters increases (up to 51.5%) per one tested bull and thirdly, the average number of effects of HYS factors increases (up to 43.1%), per one servicing bull (Zheksembekovich et al, 2020). In particular, black-and-white cattle are capable of producing 4936-6761 kg of milk, with a mass fraction of 3.80-3.96% fat in milk and 3.28-3.40% protein (Zhumanov et al, 2022).…”