Re-selection effectiveness of Kostroma purebred cattle
The research has been organized at “Experimental farm “Karavaevo” in 2015. Cows after re-selection exceed other selection types cattle in milk productivity 133kg(Р<0,001) during the 3-rd and more lactation period and 213 kg (Р<0,001) in the highest lactation time. From 70 re-selection cows 33(47%) have milk productivity more than 8000 kg during 305 lactation days. It has been noticed high breed value of bulls: Krik 9194, Ryadoc 3023, Bushuy 2726 Master›s relative 106902, Spike 5169 Leyrd›s relative group 71151 and Lednik bull 3518 Ladka›s line КТКS-253. High levels of milk production in purebreed families have been observed in animals obtained by selecting options AB × BB, AB × AB, BC × AA by EAB - blood group locus. Re-selection is of great practical importance by preparation of bulls-continuers. Thus our studies has been shown practical value of reselection in breeding dairy cattle. Genetic markers of blood groups using in selection planning allows to identify their most desirable options.