The point is: the feed that you give to 1 cow (or 1 pig) is equal to the feed of how many humans?
The feed for cows over its lifetime will feed an absurd amount of human beings. The feed for pigs I will speculate to be at least the same as feeding 1 or 2 human beings.
So even if you only had 300,000 cows being fed GMO corn, grains, etc. then this alone will feed at least the 1 billion people that are starving.