[Fixed acids in physiological parturition]

The levels of lactic acid, pyruvic acid, and L/P index in blood were studied. During physiological parturition in 25 cows it was found that the levels of lactic acid and pyruvic acid showed an increase during parturition, and this increase reached a maximum at the expulsion stage. When foetus is delivered and parturient activity decreases, the levels of the two metabolites decline gradually. The increased values of the L/P index showing the saturation of tissues with oxygen indicate some degree of oxygen starvation during parturition which does not stop when foetus is out but persists some time after parturition.