[Protein polymorphism in the crossbred progeny of Simmental and Red-and-White Holsteins].

The analysis of the genetic structure at 12 genetic-biochemical systems of pure parental breeds and their mixed offspring was carried out. The genetic structure of the mixed offspring was also investigated in relation with their differences in milk productivity. Locus-specific peculiarities of reorganization of the gene pool in the process of obtaining mixed offspring were described. Some genetic-biochemical systems involved in differentiation of groups of animals with respect to characteristics of milk production were revealed.