It’s not abuse to feed an animal a nutritionally complete diet. There is no magical nutrient that exists in animals that cannot be artificially synthesized. Just because you don’t care about animal suffering doesn’t make it necessary or justified.
Even if that was true, you’re still killing other animals which is obviously more harmful/abusive to them than not giving them their favorite food instead of the same nutrients in a different package.
It’s not abuse to feed an animal a nutritionally complete diet. There is no magical nutrient that exists in animals that cannot be artificially synthesized. Just because you don’t care about animal suffering doesn’t make it necessary or justified.