Milk production has been evaluated not only by genetic potential but there are also a lot of indicators. The potential milk production of the herd depends on the correct link between the genetic potential and the system of selection, feeding and nutrition, reproduction and the breeding environment and health of animals. The aim of the thesis was to produce a literary overview of milk production, milk composition and influences that can influence the composition of milk. For the selected herd to evaluate the effects on the monitored indicators of the milk composition and to statistically evaluate them. For discarded dairy cows to determine the age and reason of culling and lifelong milk production.