METHODICAL BASIS OF CROSSBREEDING USING IN DAIRY CATTLE

The scientific research analysis of crossbreeding using in dairy cattle of guiding countries has been implemented. There has been proved, that positive results of crossbreeding can be only for observing methodical basis of its using. They are: successful selection of initial-breeds, types and plans of theirs crossing, definition of feeding conditions and management of crossbred animals, application of methods of traits valuing, directed selection of bulls. Methodical bases of crossbreeding using in dairy cattle are following: - clear determination of main aim of crossbreeding program; - selection of improve breed may realize not for the most positive but for the less number of traits. A complementary breed shouldn’t have lower milk productivity but higher level of traits, for the sake of which it is selected to crossbreeding. It should be suitable to concrete system of milk production, have satisfactory population, the ramified genealogy and sufficient number of bulls-improvers. Plan of crossing significantly influences on the results of crossbreeding. The complex rotational crossing using 3-4 selected unrelated breeds is effective. The bulls, which are selected to crossbreeding, should have the highest estimation for traits, by which the selection is being carried out. They should be free from of exterior and genetic defects. The selection level should correspond to pure breeding. The innerbreed crossbreeding of Ukrainian Red-and-White dairy cows with top bulls of Montbeliarde, Holstein Red-and-White and Fleckvieh breeds has been suggested.