Abstract: A silage-tunneling apparatus (1) including a skid (2) on which is mounted an electric motor (30) arranged to drive a drive shaft (44) that has its axis arranged horizontally. Inner and outer hinged rigid cutter arms (45) are attached to the drive shaft and flexible chain cutter arms (60) are attached to the drive shaft between the hinged rigid cutter arms. Silage cutting elements (54, 63) are attached to the outer ends of the cutter arms. The apparatus forms a vertical tunnel (71) in silage (72) stored in a silo (70) upon being moved upwardly along the inside surface of the wall of the silo, the tunnel providing an opening for the discharge of silage through the bottom of the silo.

Abstract: A hollow piston pump (10) for pumping animal waste material including paddles (55, 155, 255) to agitate waste material collected in a hopper (11) and aid in its transfer into the hollow piston (17), a pumping chamber (14) including a cylindrical tube (76), and/or a cylindrical hollow piston (17) having antifriction bearings (90) and a seal (91) between its outer surface and the cylindrical tube (76) of the pumping chamber (14).