Ilnytska O. Breeding by lines and families of Subcarpathian interbreed type of Ukrainian Red-and-White dairy breed

The thesis presents the results of a comprehensive study of selection and genetic and biological features of different lines of Subcarpathian interbreed type of Ukrainian Red-and-White dairy breed by the dynamics of body weight growth, exterior-constitutional features, milk and meat productivity, reproductive capacity, the qualitative composition of milk, gas-energy processes, morphological and biochemical indices of blood, economic use duration and population genetic parameters. It was studied milk productivity and breeding value of top-cows and cows of different families. It is found the links between economically useful features and the indicators of milk productivity of cows, repeatability and heritability of certain breeding characteristics. The role of lines and families in the formation of highly-productive herds and the feasibility and economic efficiency of breeding was demonstrated. It was established that linear affiliation affected economically useful features of cows. The impact of the line on the live weight indicators of animals in different periods of age was 10,3-23,2, on heifers' body parts measurements - 11,3-23,2, on milk yield - 13,33-19,06, on indicators of reproductive ability - 2,74-8,65 %. The duration of economic use of studied lines cows was within 3,1-6,5 lactation. Among the estimated families - 25,6 % belonged to progressive categories, 53,5 % - to consistent and 20,9 % - to retrogressive.