Holstein Friesian calves reared in a new calf feeding program were assigned to diets of acidified (AM) or sweet (regular) milk (SM) to measure the effects of these diets on growth, health and feed efficiency. Calves' were fed AM or SM at 8% of their birth weight during 5 weeks. Two kinds of calf starters (18.5% and 17.6% crude protein) were offered to calves between birth and 4 months of ages and between 4 and 6 months of ages respectively. Weights at weaning, 4 and 6 months of ages and weight gains between various stages of the growth were not significantly affected by feeding of AM or SM. Gains in body measurements and feed efficiency values were also not significantly different among treatment groups. However, faecal consistency score and calf days with scours were significantly lower for calves fed AM compared with those consumed SM. Only frequency of milk intake among behavioural traits was significantly influenced by acidification of milk. Overall results of. the study suggested that feeding of AM resulted in beneficial effect on the lowering incidence of diarrhoea in young calves without causing an adverse influence on the growth and feed efficiency parameters.