It is interesting that you don't want to have anything to do with where food goes in and comes out, but you like eating pork, shellfish, shrimp, and all of that. They are garbage disposals. They are unclean or not food, because they eat feces, rotten carcassaes, anything dead on the ground, and the cockroaches of the sea. So, when you eat them you are eating what they eat. Look into how cancerous pigs are and the way they digest foods.
Cows, deer, chicken, turkeys and etc are good to eat because of what they eat. They are not cannibals, feces eaters, and garbage disposals.