Omelkovich S. Economically profitable characteristics of the first-calf cows of Ukrainian Black-and-White dairy breed of various industrial types

The thesis is devoted to studying the efficiency of using cows of various industrial types of Ukrainian Black-and-White dairy breed for creation of the highly efficient and competitive breeding herd. The exterior and constitution of the first-calf cows belonging to three industrial types (dairy, close to dairy, dairy and meet) as well as their dairy productivity, course of lactation, udder morphological and functional characteristics, reproductive capacity, raising economics efficiency and conformity to the desired types have been investigated. The changeability of economically profitable, technological (adaptability for machine milking) and biological (reproductive capacity) characteristics of the cows of various types as well as their correlation with complex dairy index - producing of dairy fat and protein during 305 days of lactation have been studied. The selection methods of creating the highly productive breeding herd, based on the usage of genetic factors: Holstein breed genetic potential, the best lines and grading bulls - have been practiced.