I was a vegetarian for nearly 30 years until I spent some time with a friend who runs a small holding. The care, time and expense of raising livestock is quite extraordinary. He largely feeds his family from what he produces and the veg only goes so far. Nothing is wasted, including the flayed dead skin as you call it. It was an interesting experience. I eat meat now, but try to eat small quantities from a reputable butcher wherever possible. I don’t like the idea of industrial production of meat but at the other end of the spectrum I am not sure what the future of many animals that have been traditionally farmed would be without a market for meat and it’s byproducts. At best as as prey for predators in the wild (have you ever seen what a domestic dog is capable of) and at worst many are so domesticated they would just die out as breeds that are no longer capable of survival without human intervention. There is also the issue of where they could live in the overcrowded world with declining natural habitats.