The passive immunity principles of calves and factors, which influence standards of calf-feeding were summarized in this paper. The results come from 32 dairy cattle operations across Czech Republic, where the samples of colostrum from the first milking and blood samples of calves of 2 to 7 day of age is being collected. The mean herd size is 489 cows of Holstein breed and 298 of Czech Fleckvieh breed. The imunological quality was evaluated using the method RID (Radial immunodiffusion). From 956 samples met the requirement of 50 g /L of IgG 79% of samples. The correlation between RID and values given by digital refractometer MISCO was r = 0,59. The microbiological quality was measured in 772 samples. CFU contain above 100000 CFU/ml was found in 71% samples evaluated. E. coli, the fecal contamination indicator, in values of over 5000 CFU/ml was proved in 17% samples (N=780). The IgG values in blood serum of calves of 2 to 7 day of age were determined by RID method in 737 samples. The resulting values were in 38% samples over 15g/L, in 24% samples between 10 and 15 g/L and in 38% samples under a value of 10 g/L.