Sentience seems like a weak argument though. If in the far future we encounter aliens with superior intelligence, would that make it OK for them to farm us?
Well we have sentience, so it would be consistent if I accepted the sentience criteria and also answered "no" to this question. Maybe the issue is the concept of sentience is poorly defined. I think of it as synonymous with "having qualia", i.e., having subjective experiences.
Yours is my go-to thought experiment for why some arbitrary intelligence bar doesn't give us lease to eat animals. That and the even more obvious, can I eat really dumb people?
Sentience seems like a weak argument though. If in the far future we encounter aliens with superior intelligence, would that make it OK for them to farm us?