Compatibility of lines as a factor of increasing milk productivity of Holstein cows

An analysis of the milk productivity of Holstein cows obtained by intraline selection and line crosses was carried out and the effectiveness of different types of selection in a herd of breeding dairy cattle was given. High rates of milk productivity were noted in animals obtained by crossing the V.B. line. Idiala Thus, first-calf heifers obtained from the cross of the Chieftain-Idial and Sovering-Idial lines exceeded the cows from the reverse cross in milk yield by 551-1505 kg (P