What the animal eats is vitally important.
Cows eat grass not grains and byproducts.
Pigs eat a variety of things including fruits, veggies, meats, small animals, etc.
Chickens Are essentially the same as pigs but more grain allowed.
Goats eat grass and leaves not grains.
Turkeys and most fowl the same as chickens, lots of variety.
Fish should be wild caught, not farmed.
You will at least need to go to a co-op for this, but if you can find your local weston A price chapter leader they may be able to point you to pastured meat, eggs and dairy.