Two groups of eight Friesland bull calves each were used in the trial. Calves received a commercial, coagulable milk replacer in which casein coagulation either was normal (CM treatment), or was prevented by the precipitation of Ca++ with an oxalic acid-sodium hydroxide buffer (NCM treatment). In both treatments, the daily milk replacer feeding level (percentage of birth mass) was increased from 9% (week 1), to 12% (week 2), 15% (week 3) and 18% (week 4). Calves were weighed at weekly intervals and occurrence of diarrhoea was monitored. At four weeks of age, five calves from each treatment were randomly selected for a digestibility trial of seven days. Body mass-gain and efficiency of feed conversion (kg dry matter/kg gain) were 10,4 kg and 1,7; and 10,7 kg and 1,6 for the CM and NCM treatments, respectively. Digestibility coefficients were 90,2 and 91,1 % (dry matter), 91,9 and 93,6% (organic matter), and 81,0 and 85,6% (crude protein), for CM and NCM respectively. It was concluded that prevention of abomasal curd formation had no effect on body mass-gain, occurrence of diarrhoea, or digestibility of dry matter, organic matter and crude protein. Digestibility coefficients remained high, even at a daily feeding level of 18% of birth mass.