I'm currently unconvinced either way on this matter. However, enough arguments have been raised that I think this is worth the time of every reader to think a good deal about.
http://nothingismere.com/2014/11/12/inhuman-altruism-inferential-gap-or-motivational-gap/
I don't think this gives due respect to the premise. Imagine yourself in a world where attitudes towards meat eating were similar to ours, but the principal form of livestock were human. You'd like to reduce the number of people being raised as meat. Would arguing your ethical position on a site called LessWrong be worth your time, even if most people there weren't very receptive?
No, what would be worth my time is to figure out how to make less sentient animals taste like humans. Maybe popularize pork, or something.