An auger for a vertical livestock feed mixer having an open-top mixing tub is provided. The auger includes two flights to draw in feed components from the bottom of the mixer tub and move them to the top. The trailing edge of the upper auger flight includes an upraised portion to deflect feed components towards the sidewalls of the feed mixer. The leading edge of the lower auger flight includes a kicker plate on the topside of the flight to deflect feed components towards the centre of the auger.