Passive transfer of maternal immunity via colostrum to the newborn calf is vital especially in dairy cattle, but it’s still not fully mastered worldwide. This study, as the first in the Czech Republic, is based on a gold standard for the evaluation of colostrum immunity, i.e. direct IgG assay in calf serum by radial immunodiffusion. This was performed thanks to the introduction and testing of this method. Simultaneously, for comparison and practical use, the total protein concentration was measured by a digital refractometer (CB-R) and laboratory photometrically (CB-L). In 717 samples from 38 herds the concentrations of IgG, CB-R and CB-L (mean ± SD) were determined, namely 14.3 ± 7.4; 54.8 ± 8.1 and 57.6 ± 9.3 g/L. Using the limit values 10 g/L for IgG, 52, resp. 55 g/L for CB-R and 55, resp. 60 g/L for CB-L, the percentage of samples below the limit was determined. Regarding IgG, the proportion of samples below the limit was 31.9%, i. e. the failure of passive transfer was diagnosed in nearly a third of calves. When testing the accordance of grouping of calves equipped with maternal immunity in satisfactory or insufficient manner by concentration of CB-R and CB-L compared to the IgG standard, a more bal­anced conformity resulted when lower limit values were used. At the limits of CB-R 52 and CB-L 55 g/L, 37.2 and 41.7% of samples were below the limit. Correlation between IgG and CB-R, resp. CB-L reached values of correlation coefficient r = 0.70, resp. 0.68. Correlation between CB-R and CB-L was r = 0.88. The practical possibilities of systematic monitoring of passive immunity transfer are discussed.