My friends Kid thought Bacon and Steak were something the pig or cow made, like Milk or Butter, rather then the mussle of the animal. Some how we explained that we were Omnivors nad explained Omni, Herbavores and Carnavores. We simply explained that we were on the top of the food chain and we could eat either meat or vegtables and that we figured out if you cook the meat or vegtables we can get more nutrients from it.
As to a sloughter house the subject never came up but was ready with a simple that is where the amimals get turned from amimal into food. Butchers, and cooks take the large sections of the animals and break them down into usable parts. bacon, steaks, roasts and what is left becomes sausage and hotdogs and other yummy things. The parts that are not so good become dog and cat food, but everything in the animal is used.