Earlier quoted context omitted.
I don't see how it would be "convenient", since it doesn't seem necessary that an animal be conscious for us to require ourselves to not harm it out of a moral concern. Babies are either unconscious or have a very low degree of consciousness, but infanticide is still morally abhorrent.
I agree that there is a moral aspect to eating sentient being, whether they are conscious or not. Your argument, however, is mixing the aspects of consciousness, and cannibalism in the form of infanticide. To me, that doesn't seem to be fair.
What do you find unfair about the example?