[Annual dynamics of acid-base equilibrium indices in dairy cows]

Annual dynamics of the indices of acid-base homeostasis of blood was studied in dairy cows in two production regions, the corn production region and the potato-grain production region; venous blood was examined gasometrically by the Astrup apparatus. The examinations were performed eight times during the year and pH, pCO2, BE, PB, SB, AB and tCO2 were studied. In dairy cows from the corn production region lower values of the studied parameters were obtained than in dairy cows oriented to similar milk production in the potato-grain production region. In the corn production region besides the normal values also the lower values of the indices of acid-base balance were found, indicating the incidence of latent metabolic acidosis. A particularly critical situation occurred in the herd from the corn production region in September when the average value of blood pH was 7.35 logmolc and the following disorders were observed: clinical symptoms of metabolic acidosis, drop of milk yield, drop of milk fat content, hypomagnesemia and hypocalcemia as disorders of the mineral metabolism.