Four experiments were carried out in which supplements of locally available proteinaceous by-products were given to young, mainly pre-weaned calves that ranged in initial weight from 30 to 90 kg. The experiments were part of a programme designed to establish practical and economical nutrition interventions for the improved productivity of N'Dama cattle under traditional village husbandry in a sub-humid agro-ecological environment in West Africa. The supplements included groundnut cake, sesame cake, and cotton seed, supplied during both the dry and wet seasons. While significant increases in growth rate were obtained to both dry and wet season supplementation, the responses were both inconsistent and much smaller than those obtained in other studies with older weaned N'Dama cattle. It is concluded that feed supplementation of young cattle should probably be restricted to animals whose liveweight exceeds 100 kg.