The acid-base equilibrium is of vital importance for living organisms. Its shifts affect practically all life processes, thus resulting in decreased milk production, sterility, etc. which may cause economic losses. Strong alcalosis in the dry period raises the risk of milk fever after parturition. Examinations on an organic farm were performed because of cumulative occurrence of milk fever and retained placenta. One total mixed ration with excessive supplementation of minerals was fed to all milking cows. The rest of this ration was fed to the cows during the dry period. Net-acid-base-excretion in urine showed a strong alkalosis especially in the dry cows. After modification in feed man-agement milk fever and retained placenta never occurred during the observed period. Blood examination, especially in calcium, and net-acid-base-excretion showed better results after these modifications
