Just to be clear....I'm hoping you over exaggerated this to make a point and realize hog confinements are not like that.
Not really. Just thinking of examples off the top of my head. My wife's family owns two fairly recently built confinements, and I have worked in them.
The older confinements have issues with leaky manure containment from lagoons or the concrete basins. The new ones are better, but it's definitely something that needs oversight and regulation IMO. The ubiquitous hog confinements and cattle feed lots in Iowa are one of the biggest causes of surface water pollution and nitrification.
If you work in a hog confinement too long without a respirator, you can have some serious health problems from the strong ammonia fumes. How would you like to be one of the pigs that live in there permanently? It would suck.
As to the cannibalizing, some hog farmers simply assume that pigs are just "like that", but animals do funny things when they are held in confined spaces along with hundreds of others, with nothing to do but chew each other's tails off. Once they get a taste for flesh, any pig that is vulnerable (sick, leg trapped, etc.) will get eaten alive. Pigs are intelligent animals. When intelligent animals get bored, they do weird stuff. Like primates in zoos throwing poop. You think they do that in the wild?
Don't get me wrong. I'm not a PETA-pocket or Vegan. I like meat, and I have a great respect for animal husbandry. I know lots of farmers and ranchers that love and respect the animals they are charged with, and care about minimizing their suffering. I just think that the industrialization of meat production has come at a great cost. It has dehumanized the tradition of animal husbandry.
You are a religious man, BRB. The bible tells us that plants and animals were created by God for humans use. To me, that means we should respect that gift, and not exploit or destroy natural resources wantonly. Also, Jesus was the "good shepherd" who would give his life to protect his sheep. Just the way I look at it. If we eat meat, we have to be OK with animals being killed for that purpose. We don't have to make their lives hellish in the process, though.