People from certain areas of the world seem to have a massive grudge against pigs.
I was working with a lad recently who said his dad (who's Palestinian) advises him to never go near pigs or pork, and that he wouldn't do anyway "because of how disgusting they are as animals."
For farm animals, they're actually really intelligent. Almost like dogs. I don't understand why so many people would take such a disliking to such a nice little creature.