Why are pig brains dog food? Because they're below the arbitrary threshold of intelligence we have drawn in the sand to determine sentience?

What if there was extra-terrestrial life of greater intelligence still that encountered our own species, and subjected us to identical treatment according to the exact same basis of morality?

I honestly can't tell if you're trolling, since your wording sounds like it's meant to provoke, but I'll answer you earnestly.

Why should edibility take precedence over sentience? Humans are edible, after all.

What a strange argument.

Could you not also argue that dog brains are pig food?