The application of selection and genetic parameters in breeding work with dairy cattle

Selection and genetic parameters allow defining optimum directions in the organization of selection and breeding work. The research objective was the determination of selection and genetic parameters of cows’ milk efficiency. The object of the research- es was the livestock of cows of black and motley breed numbering 255 heads bred in breeding plant of Federal State Unitary Enterprise ‘Omskoye’. Se- lection and genetic parameters of cows of various production groups bred on the farm were studied. The coefficient of inheritance of milk yield on herd averaged 0.237, with extreme deviations from0.119 to 0.341. The inheritance of milk fat content was in the limits 0.380-0.482. The accounting of interrelation between economic and useful signs was of great importance at selection of animals. In young cows the interrelation between milk yield for lactation and milk content of fat was practically missing, the coefficient of correlation made 0.012-0.015. In full-age cows weak negative interrelation between the yield of milk and the content of milk fat was observed, the coefficient of correlation varied from -0...