A feed mixer truck for mixing feed and for discharging mixed feed into an elongated feed bunk. The engine of the truck is mechanically connected to three hydraulic pumps which are hydraulically connected to a hydraulic motor for driving the drive wheels of the truck, which are hydraulically connected to a hydraulic motor for operating the feed mixer augers, and which are hydraulically connected to a hydraulic motor which operates a feed discharge assembly. A control is electrically connected to the motors to control the operation thereof.