IIRC, every bushel of corn processed for ethanol produces about 3 gallons of ethanol and about 20 lbs of animal feed. And, from what I understand, the feed produced is much richer than the corn before the processing, so it displaces about 120%.
IOW, 100lbs of ethanol-processed feed takes the place of 120lbs of corn. Not sure about all that.
I'm not crazy about using it for ethanol but I don't think it's as bad as some think. Technology is good in the right hands.
In the wrong hands -- Well, those people screw up everything they touch anyway, so.................