Koval'chuk T. Economic value and biological characters of cows of various genotypes of new dairy breeds of a new intensive type

The thesis deals with the investigation into the exterior and constitutional characters, milk and meat yields, reproductive and adaptive features, morpho-functional peculiarities of udder in cows of various genotypes of new Ukrainian black - and - white and red - and - white dairy breeds. For the first time, under the conditions of a single enterprise located in Polissya - Forest - steppe zone of Ukraine a comparative integrated assessment of the economic value and biological characters of first - calf cows of various genotypes by Holstein breed is made. The above comparison considerably proves the authenticity of the conclusions and investigation results obtained. With respect to high genetic potentials and requirements as to the environmental conditions as far as Holsteinized animals are concerned, special attention is paid to the investigations into their reproductive capacity, resistance to lactation, clinical and exterior indices which characterize their adaptive peculiarities and metabolism intensity in animals of various genotypes. It has been proved that a higher portion of Holstein breed heredity in cows genotypes of both breeds results in their better productivity though with a worse reproductive capacity and beef qualities.