Abstract: A rotor assembly for use in a poultry harvester, comprising first and second rotors arranged side by side about a center line of the assembly for rotation about vertical or predominantly vertical axes, a third rotor equispaced from the first and second rotors in a direction along the center line of the assembly, and drive means for rotating the third rotor in a clockwise or anticlockwise sense, as desired, during operation of the assembly, the drives for the first and second rotors being derived from the motion of the third rotor and being operative to counter-rotate the first and second rotors in rotational senses which remain unaltered irrespective of the direction of rotation of the third rotor at any given moment, each rotor providing a continuous array of radially-extending guide elements closely adjacent and/or abutting and/or intermeshing with the guide elements of the other rotors.