I don't need a reason, neither animals nor fetuses are sapient and Idgaf about them.
I do think we should reduce our meat consumption, but that is only so that we don't overexploit the environment and cause catastrophe, and so that we can eventually establish council communism and redistribute resources more evenly between the proletariat, so we may all benefit from nature's spoils rather than the inherent inequity of the owner-worker system we have now.