There are no animal by-products of unknown origin: it is undeniable that there are animal by-products in natural grains now, but if the source of by-products, such as deer liver, is indicated, there is no problem. If only by-products are marked, the source is unknown.
No grain: cats will weaken their immune system if they digest grain; Source of meat: ideally, specify what kind of meat it is; Vegetarian and vegan cat food, vegetarian cat food must strengthen nutrients, cats are natural carnivores, and these nutrients cannot be synthesized from plant food.
Extended data:
Because cats are complete carnivores, the main sources of energy and nutrition should come from animal protein and animal fat, not carbohydrates.
Strictly speaking, if cats have enough animal protein and fat in their daily diet, they can live healthily without carbohydrates at all.
The dry food for cats in the market often contains a lot of grains, so that the carbohydrate content is as high as 35% to 40%. Cat's body structure is not good at dealing with a lot of carbohydrates. For example, if cats eat foods containing a lot of carbohydrates day after day, the chances of developing diabetes and obesity will greatly increase.
References:
Baidu encyclopedia-cat food