The present invention relates to a feed mixer (F) comprising at least one rotatably drivable mixing member (M) and at least one planetary gear arranged on the feed mixer (F) and driving the mixing member (M), said planetary gear comprising a sun gear (25), a planetary gear carrier (22) with planetary gears (23) and a ring gear (24) as torque transmitting components in a housing (14) and being adapted to be shifted under load with at least one clutch (K) between at least two gear ratios. According to the present invention, the planetary gear comprises in the housing (14) a single clutch (K) between two of the components and on the housing (14) a brake (B), which is actuable on the feed mixer (F) and which can be used for optionally blocking one of the two components relative to the feed mixer (F) as well as for disengaging the clutch (K).