Voitenko , S.L. and Sydorenko , O. 2019. The impact of improving breed on dairy productivity of cows of different breeds of domestic selection . Bulletin of Sumy National Agrarian University. The series: Livestock. 4(39) (Dec. 2019), 43-48. DOI:https://doi.org/10.32845/bsnau.lvst.2019.4.6.