Genetic structure of animals of several Ukrainian modern breeds analysed by genes of protein and lipid exchange CSN3 (kappa-casein), BLG (betalactaglobulin), LEP (leptin), Pit-1 (pituitery transcription factor), TG-5 (thyroglobulin) were investigated in cows of three domestic breeds (Ukrainian Red Dairy, Ukrainian Black-speckled Dairy, Ukrainian Red-speckled Dairy). Polymer-ase chain reaction, followed by restriction fragment length polymorphism was used for the molecular-genetic analysis.