J agos P., Bouda J.: Protein Metabolism in Cows and their Calves Fed from Buckets. Acta vet. Brno, 49, 1980: 59-66. The level of total protein, protein fractions, immune globulins in blood and colostral serum of 40 cows and in blood serum of their calves up to the age of 3 months were determined. No significant differences in the concentration of total proteins and their fractions in blood serum in cows ante and post partum were found. The concentration of total protein in colostral serum was found to be signi ficantly higher (P < 0.01) than that in blood serum of cows. The average value of total protein in blood serum of calves prior to the ingestion of colostrum was 41.7 gil. The gamma globulin values in blood serum of calves reached the maximum after 24 hours upon the first ingestion of colostrum. The lowest gamma globulin values were found in calves of 3 - 6 weeks of age. Immune globulins correlated with gamma globulins and decreased below the standard in almost 50 % of calves 3 days old. The absorbed gamma globulin from colostrum participated in increasing the total protein content in blood serum of calves. Besides the determination of serum gamma globulins and immune globulins the total protein determination by the re fractometric method can therefore be used for the diagnosis of hypogammaglobu linemia in calves. The level of serum immune globulins should not fall below 20 units and should be measured from the 2nd to 7th day of calf age. Late and less frequent colostrum ingestion was found to be one of the causes of low immune globulin levels. Cow, calf, blood serum, colostrum, proteins, albumins, globulins, gamma globulins, immune globulins, electrophoresis, hypogammaglobulinemia, metabolism.