The thing that gets me is that pigs apparently do as well on intelligence tests as human toddlers. Imagine a factory where toddlers are crammed in cages to be slaughtered and then have their flesh ground up and sealed inside their intestines so they can be eaten with HP Sauce. 
Cognitive dissonance, I guess. Compartmentalisation of different worldviews. (I eat meat btw. But I'm trying to mostly eat really stupid creatures like prawns.)