I have a pet pig. If he’s free to bounce around on a ride, he’s going to fuck himself up and any animals near him. Pigs panic at a pin drop and they’re far heavier and more powerful than they look. They’re tightly confined when traveling for the same reasons horses are.
Also if you see a livestock truck on the road. Get away from it. Especially if its raining. ESPECIALLY if you are on a motorbike or driving a convertible. Animals dont stop pissing and shitting just because they are on the truck.
You want your vehicle shotgunned with a pig excrement slurry? Nah didnt think so.