The aim of the paper was to analyse the relation of milk yield per cow with a set of production factors on sample data from six dairy farms located in the central region of Poland. The farms, which were the subject of the study, carried out an intensive production, achieving milk yield over the national average. The research showed an increase in milk yield with increasing number of cows in the herd, which, in practice, can lead to increased loads in milking installations in farms keeping more cows.