EN
The purpose of the work was to determine the level of acetone simultaneously in the blood and milk at the starting period of lactation, ie between 2 and 6 weeks after parturition. The concentrations of acetone in the blood and milk were closely correlated and the index of correlation was very high (r = 0.960). A mean level of acetone in milk was on an average lower at 39% compared with that in blood. In the group under study the individuals with the level of acetone in the blood and milk over 250 and 170 µmol/1 respectively constituted 42.5% of the animals.