Abstract: A horizontally oriented three sided frame is adapted to hold a round hay bale. An endless chain driven conveyor encircles the floor of the frame to cause the round bale to rotate about a longitudinal axis thereof while simultaneously urging a portion of the perimeter of the bale against a rotary drum cutter arrayed just above the floor on one side of the frame. The cutter chops the hay bale into individual strands for feeding to livestock. A spacer, commonly called a concave, is pivotably attached to the frame, and is spaced from and extends longitudinally along the top of the rotary drum. The spacing between the concave and the drum is adjustable. By adjusting this spacing, as well as the speed of rotation of the rotary drum and the speed of rotation of the round bale via the conveyor, the length of hay strands cut by the cutter is adjustable.