The invention relates to a single-part feeder body for use as a feeder insert or component of a two-part or multi-part feeder insert in metal casting, having a feeder wall which at least partially delimits a feeder cavity for receiving liquid metal, wherein the feeder wall has an inner surface facing toward the feeder cavity, an outer surface for bearing against a mold material that surrounds the feeder body in certain regions, and a passage opening for the liquid metal into the feeder cavity, wherein the feeder wall has, on the inside, one, two or more material recesses for forming one or more outwardly protruding projections on the metal solidifying within the feeder cavity.