Faulty logic: A valid in set S => for a subset of S A is valid. Not the other way around!

Regardless, i do think animals have some rights. In the thread "What are your axioms" I considered a ethical axiom that claimed that the ultimate goal should be increasing feel-good of all creatures weighted by something.
One question with that is then what those weighs are. We could try equating it to consciousness, but then, what is that? I guess that what we associate combined with what creatures do with given freedom is the only measure we have available. There might be some relation with size of nervous system but i have no idea if that is usable.