Summary Studies involving 185 Holstein calves were carried out to formulate substitute mixtures which would satisfactorily replace fluid whole milk in the ration of dairy calves after 10 to 14 days of age. Approximately normal rates of growth were obtained with mixtures containing large amounts of dried milk solids. In general, however, calves raised on the substitutes were rather rougher in appearance from the third to the seventh week of age than calves fed whole milk. As an average, the rates of growth were somewhat slower on the substitutes during the first month than on milk, but the differences largely were overcome by the time the calves were 4 to 6 mo. of age. Mixtures containing 20 per cent of high-fat soya flour, or dried beet pulp, or as much as 60 per cent of dried whey resulted in slower growth rates and more digestive disturbances than the other mixtures studied. Banana meal and apple pomace appeared to reduce the incidence of scours; however, all of the mixtures studied caused more diarrhea than fluid whole milk. In limited digestion studies, dried whey, glucose and sucrose appeared to be highly digestible for the young calf, whereas corn starch and banana meal were less available.