An agricultural harvester (10) has a chassis (12) carrying a threshing and separating system (24) for separating grain from Material Other than Grain (MOG). The threshing and separating system (24) has a threshing rotor (40) and at least one concave (42). At least one rasp bar (84) is attached to the threshing rotor (40). The at least one rasp bar (84) has an upper threshing surface (88) and a trailing surface (90). The trailing surface (90) is set at a draft angle (α). At least one trailing surface interrupter (92) is located on the trailing surface (90) and may be inclined slightly rearward from vertical. The trailing surface interrupters (92) may be used with rasp bars (84) with or without rasp bar spikes (86).