As far as I read, the Buddha allowed the eating of meat – as long as the kill was not carried out specifically for Him or the Bhikkhus. When the meat is there ready for consumption, the deed has already been committed.
But this needs going into a bit further. If there were no killing of animals – no slaughterhouses, no fishing, no hunting -many communities on the planet would die of starvation. A counter argument by the ‘pro-life’ activists goes: if everyone started refraining from eating meat as from tomorrow, the demand would not be there, so eventually neither will be the supply. End of the problem.
Yet the Dhamma takes Reality into account. It is in fact an account of Reality. People kill, even other humans. People steal, lie etc. So the Precepts address that which is real. Any kind of evil will always be around, as long as humans are around. That is, for ever. But Nature or Existence wastes nothing: it works even with the evil of humans to sustain them, bringing about kamma vipaka to those animals and paying back debts to the consumers in the process. And there must be other factors as well, of which I am altogether ignorant.