There has been some discussion on the suitability of double-deck “pot” trailers designed for cattle for use with transporting pigs. Some people have advocated never using these trailers for transporting pigs. They maintain that pigs should always be hauled in “straight” trailers where all internal ramps have been eliminated. I agree that these are the best trailers for transporting pigs. However, there are some situations where flexibility is required so that the trailer can be used with both cattle and pigs.
Recently I visited a pork plant where many of their pigs had been raised outside and I watched them unload market weight pigs from double-deck “pot” cattle trucks. I observed four or five cattle trailers of pigs being unloaded. In this particular plant, I could see directly into the back of the trailer without interfering with unloading or handling. All the trailers were unloaded with zero electric prods. The pigs walked easily down the top deck ramp and willingly came up out of the bottom deck. None of the animals fell when they walked down the top deck ramp. If I had done a welfare audit, the falling score and the electric prod score would have been zero. All the pigs were heavy, weighing approximately 275 lbs.
The immediate rebuttal to this might be the entire industry cannot raise pigs outside. I would agree with this statement. There are many things that can be done to make standard indoor commercial pigs easier to handle.
The first step is breeding for good foot and leg conformation. The pigs I observed unloading from the cattle trucks had excellent feet and legs. In both pigs and cattle, leg conformation problems, such as too straight “post legged” or collapsed ankles will cause mobility issues. In both species, this problem is more likely to occur when the animals are indiscriminately selected for lots of muscle and rapid weight gain. Problems with poor feet and legs can creep up slowly and people may not realize it. I call this “bad becoming normal.”
Another problem that can make pigs difficult to handle at the plant is failure of the producer to walk their finishing pens. Pigs differentiate between a person walking in the aisle and a person walking through them in their pens. Every day, the finishing pens should be walked in a different random direction to train the pigs to quietly get up and move away. If the finishing pens are never walked, the pigs will be harder to load onto the truck at the farm and more difficult to drive and move at the plant. Instead of moving quietly away from the handler, they are more likely to pile up, squeal and bunch tightly together. People who work in the stockyards know which farms produce difficult-to-drive animals. This is an example of an issue that must be corrected at the farm. When a group of pigs originates from a farm with a combination of pens never walked and poor leg conformation, there may be a greater possibility of having a humane handling issue.
To go back to the issue about “pot” cattle trailers for pigs, is the solution to pig transport problems to add more automation such as hydraulic lift decks or is the solution to produce a pig that is easier to handle and transport? A major part of the solution is correcting problems with difficult to handle pigs at the farm.