The effects of liquid feed and feeding frequency on concentrate mixture intake, rumen fermentation and rearing performance were investigated in 24 bull calves divided into 2 groups, receiving milk or milk-replacer once or three times a day. VFA concentration was estimated in the rumen fluid at 36 and 90 days of age. The liquid feed did not influence the concentrate intake (P>0.05). The calves receiving milk were characterized by higher concentration of butyric acid in the rumen fluid (P≤0.02) and higher daily weight gains (P≤0.02) compared with those fed milkreplacer. The increasing feeding frequency during the period from 7 to 36 days of age was reflected in lower daily intake of concentrate mixture (P=0.02).