Ladyka , V., Sklyarenko , Y., Pavlenko , Y. and Malikova , A. (2020) “Comparative evaluation of dairy productivity of cows of ukrainian brown milk breed of different genotypes by β-casein”, Bulletin of Sumy National Agrarian University. The series: Livestock, (3 (42), pp. 3-7. doi: 10.32845/bsnau.lvst.2020.3.1.