Nutrition of dairy cows is based on the possibilities of the farmers to divide the herd according to preference of three, four or six-phase nutrition of dairy cows. In general, the nutrition can be divided during the milk production as follows: (1) beginning of lactation (the first 100 days of lactation), (2) middle lactation (the second 100 days of lactation) and (3) end of lactation. The length of the lactation can be variable. Duration of standard lactation period is 305 days. In large herd of dairy cows is recommended to build groups according to heifer, milking cows and healthy problems. Separation of cows after calving is not necessary. However some farmers prefer to build groups of cows approximately 14 days after calving. An advantage can be a better individual approach and easier identification of sick cows, easier temperature measurement and better manipulation with dairy cows.