Animals as Food Revisited

I have been revisiting my position on animals, their rights, etc. I posted on this in April, though I have just now received feeback.

I have, quite honestly, not completed my consideration of the matter. As of right now, I am still an omnivore, simply because I am not convinced that it is immoral (please spare me the obvious logical fallacy - I know.). The change in my opinion is the result of an abortion essay written by Don Marquis.

In this essay, he finds a new angle on the subject, saying that abortion is wrong by defining the act of killing. His definition says that killing is wrong because it deprives the subject of future experiences, projects, etc. I find this definition highly appealing.

But if I agree with this definition, do I have to change my stance on the morality of killing animals, who are outside my social contract? Is there perhaps other modes of moralty, such as logic and reason? If I accept the above definition, and an animal is capable of these projects, experiences, happenings and what not, am I immoral in killing them? Am I capable of judging whether they have these future occurrences?

I think one of two things will happen as I consider this conundrum:

A) Either my definition of killing and it's morality will adopt Marquis's doctrine, in which case I shall have to find a way to reconcile it to my current theory, and even include animals.
B) I will either find a reason to reject my own contract theory or Marquis's doctrine.

Either way, I am excited at the prospect of solving the issue.