But you do guess, because it's a cow. You don't know you aren't a cow (I guess?).
60 years ago they thought that babies did not feel pain. I suppose we can always rely on our intuition to tell us what's true or not.
Some people still think animals don't feel pain, or have feelings at all. Anybody who has spent time with one of them will know that's bs.
Why couldn't cows have a concept similar to what we consider property? Just because they are "inferior" to you.