The majority of calves in Britain (2-3 m a year) are artificially reared and receive less milk than they would if suckled. It is therefore important that calves should develop early in life the ability to consume and digest solid food. Traditionally, calf starter diets are formulated to contain rapidly fermentable cereals as the major energy source, which is adult cattle cause a depression in rumen pH to below 5.5 and inhibits food intake (Fulton, Klopfenstein and Britton, 1979). In experiments which have demonstrated a beneficial effect on food intake from the inclusion of roughages in all pelleted diets based on cereals appear to be associated with the concurrent increase in rumen buffering capacity (Thomas and Hinks, 1982). The appetite of the calf may have been constrained by low fibre digestion (Williams, Innes, Brewer and Magadi, 1985) and the bulky characteristics of the roughage. Two experiments are reported in examining the potential of replacing the energy source, of calf diets, supplied by cereals with materials of high buffering ability, but without the bulky and indigestible characteristics of roughages. Expt 1 examined the effects of replacing rolled barley (RB) with molassed sugar beet feed (MSBF) or lucerne meal (LM). Expt 2 examined the factorial replacement of RB with MSBF.