Temple Grandin
Colorado State University

Livestock Handling Pre-slaughter

                     
        Center track double rail restrainer.  This system is available for both sheep and cattle.

A new double rail conveyor restrainer system designed by the author is based on research by Geiger et al. (1977) and it is adjustable for a wide variety of animal sizes.  Baby calves, sheep and large 225 kg (500 lb.) calves can all be handled in the same restrainer.  For adult cattle, a slightly wider conveyor is used.  The width of the moving conveyor that the adult animals straddle is 30 cm (12 inches).

Standard V restrainer conveyors may cause petechial hemorrhages during electric stunning (Thornton et al., 1979; Lambooy, 1986).  There is a possibility that this new system may reduce blood splash and speckle in electrically stunned animals (E. Lambooy, 1987, personal communication).  With the double rail conveyor, animals are supported under the brisket and belly while straddling the conveyor so that even large wild calves will ride quietly.  The double rail requires less space than a V conveyor restrainer and it is compatible with existing shackling and bleeding systems.

Proper design of the system is essential.  The top of the conveyor is level with the floor of the entrance race.  The animals walk down a cleated nonslip ramp which is on a 25 degree angle.

               

       Animal entering the center track restrainer. 
 It is very important to have a non-slip ramp with cleats.

This same ramp design is also recommended for V conveyor restrainers.  The sides of the ramp must be closed in, and animals must not see light coming up through the bottom of the restrainer.  A stationary leg spreader bar over the ramp and in the first section of entrance race guides the animal's legs to the correct position.  Calves entered this system with less balking compared to a V restrainer.  The conveyor is constructed from metal segments attached to a moving chain.  Each segment is bent to form the double rail configuration.  Total width of the conveyor frame is 21.5 cm (8 1/2 inches).  The moving segments are 19 cm (7 1/2 inches) wide with a 7.6 cm (3 inch) space in the middle to accommodate the animal's brisket.  For adult cattle, a slightly wider conveyor is used.  The width of the moving conveyor that the adults animals straddle is 30 cm (12 inches).

To induce the cattle to stay still and ride quietly, the solid hold down rack MUST be long enough so that the animal entering the restrainer can NOT see out until its feet are completely off the entrance ramp.

This system MUSt have a solid false floor just below the animal's feet.  Cattle will balk and refuse to eneter if they see a steep drop-off below the conveyor.

Adjustable sides accommodate different sized animals.  The adjustable sides press lightly against the top portion of the animal's body.  They are on pivots and the bottom edge of the adjustable side is slightly above the top of the conveyor.  This provides room for the animal's leg joints.  Pressure on the leg joints causes stress and discomfort.  The pivot mechanism simultaneously adjusts the width between the sides and the leg joint space.  For calves, the width between the adjustable sides can be varied from 51 cm (20 inches) to 25 cm (10 inches).  The space between the bottom of the adjustable sides and the top of the double rail is 5 cm (2 inches) when the sides are spread 25 cm (10 inches) apart and 12.7 cm (5 inches) when the sides are spaced 45 cm (18 inches) apart.

     
           Full size double rail restrainer for adult cattle

Another very important design feature is the solid hold down rack and the solid false floor.  To keep the animal calm, the hold down rack must be long enough to prevent the animal from seeing out until its rear feet are off the entrance ramp.  The solid false floor prevents the animal from seeing the "visible cliff" effect under the restrainer.  This greatly reduces the amount of animals balking and refusing to enter.

The solid false floor is essential to facilitate cattle entry into the restrainer.  These diagrams illustrate dimensions for adult cattle.  Dimensions for calves are given in the previous text.

These diagrams illustrate dimensions for adult cattle.  Dimensions for calves are given in the previous text.