From Where Does Animal Value Come?

Animal value stems from a variety of different sources, and is incremental depending on those sources. The foundational capacity for value comes from sentience - the ability to experience and process pain and enjoyment. The capacity for sentience gives an organism a value that demands freedom from harm and the cessation of enjoyment. There are also a number of other factors that give an organism value: intelligence, ability to learn, instrumental value, et cetera. These capacities comes in different degrees, and is therefore incremental. An organism with a higher capacity to experience pain is more valuable in that way, than an organism with a lower capacity to experience pain.

These differences may be relevant in some situations, but they do not generally make a difference so long as we accept the basic value of animals and the treatment that such a value would warrant. A random pig because of it's higher sentience and intelligence, has a higher moral value than a random cow. This does not mean that we should treat cows less well, it means that when forced to choose one animal worse, we ought to choose to treat the cow worse. In most everyday situations, this is irrelevant, but that does not mean that it is entirely useless.