Fifteen dairy calves were kept with their dams for 5 d after birth and thereafter were fed milk from a nipple pail in individual pens (nursed calves). Another 15 calves were separated from their dams immediately after birth, placed in individual pens, and fed from an open pail (weaned calves). These calves received colostrum for the first three feedings. Serum Ig concentrations and the health of the calves were monitored from birth to 12 wk of age. The serum Ig concentrations developed identically for calves in both groups. A 30-min delay in intake of first colostrum decreased total Ig concentrations in serum by about 2 mg/mL. Occurrence of diarrhea was three times greater for the weaned calves than for the nursed calves. Serum Ig concentrations did not explain the differences in the diarrhea occurrence between the groups. In conclusion, the newborn calves in both management systems acquired equal passive immunity, although the time of first colostrum consumption played an important role. Open pail feeding may increase the incidence of prolonged diarrhea compared with that from nipple feeding.