Each unloading ramp had rubberized flooring and measured 1.7 m wide × 8.1 m long. Angle-iron cleats extended across the width of each ramp and were spaced every 25 cm along the entire length of the ramp. The ramp angle, when raised to the lower and upper trailer decks, was approximately 9° and 19°, respectively. All pigs were transported by drivers who were employed by the packing company on trailers owned by the packing company.