The first 2 are the best. Most pet foods use by-products. Chemically, this will analyze out as protein, but obviously your pet can't get much nutrition from this type of protein. Most pet foods are preserved with artificial chemicals. Ethoxyquin, BHT, BHA etc.
Many foods have artificial flavorings and colorings.
Unfortunately, most won't be found in the store. One, without all the preservatives, they don't have a long shelf life and thus might spoil in giant storage warehouses. It costs more to put REAL MEAT and whole grains in foods than it does by-products. Health food stores, smaller pet shops that specialize in nutritional products, and now, by mail order, or online. Or if you call, we can give you the toll free numbers.