The article presents the results of studies of milk productivity of Holstein cows in the dynamics of lactation, correlations between the level of milk yield, fat content, amount of milk fat, and live weight. The research was carried out in the herd of the breeding farm of Society of limited liability "Doksancom", on Holstein cows in the dynamics of lactation, as well as first-calf heifers of various origins. For each subsequent lactation, the milk yield of cows in the herd of Society of limited liability "Doksancom" increases. It was established that milk productivity for the second lactation was by 1468 kg of milk, for the third - 1215 kg of milk, for the fourth-sixth lactation - 1199 kg of milk more than for the first lactation, the difference is significant at P<0.001, P<0.001 and P<0.01 respectively. Comparative analysis of the milk yield of first-calf heifers raised in various farms showed that first-calf cows raised in the herd of Society of limited liability "Doksancom" had the highest productivity - 9518 kg of milk, which is by 925 kg more than first-calf cows purchased from the breeding farm of Joint-Stock Company "Aydyn", the difference is significant (P<0.05) and per 1200 kg - first-calf cows imported from Holland (P <0.01). The relationship between milk yield and the percentage of fat in milk of cows was in a negative correlation from weak -0.154 (IV-VI lactation) to moderate -0.409 - -0.449, II and III lactation, respectively.