The trouble is that it is pretty damn tough to pivot from corn to some crop meant for direct human consumption. The machinery and infrastructure we have in place to grow, transport, and process corn is almost unimaginable in size.
A pivot like this would require incredible gov't subsidies and take decades.
Also, my family is from the north of Argentina, so during the holidays there during one or two weeks fresh corn was very cheap. So we ate sweet humita and spicy humita https://en.wikipedia.org/wiki/Humita, sweet corn pie and spicy corn pie, also whole fresh corns, and other stuff. We joked that we ate some dish with corn for lunch and some dish with corn for dinner for a week.
In fact reducing corn yields and switching to a different crop will save farmers
money as framers have to over supply fertilizer as they are planting corn too close together to get yields without using fertilizer i.e. corn take out more from soil than it gives back
100% on the cows, wrong on hard to grow. Growing in mass quantities is hard on the local environment (global if you count the affects from usage). Corn fed beef is bad.
Surely, we must know how to do this. I mean, we know how grass-eating ruminants break down the cellulose to obtain energy with various enzymes and whatnot. We could probably invent some kind of exo-stomach to pre-digest grass into an edible state. :)
Starch and cellulose are both glucose polymers. The only difference is the way in which the glucose units are attached to one another. Existing enzymes can only cleave one or the other. Ruminants don't actually have the necessary enzyme, but instead rely on bacteria in their stomach to do this for them.
I guess if you really wanted to, you could take cellulase in the way that people can take lactase to mitigate the effects of lactose intolerance.
How you'd actually get your stomach to brew that up into anything useful in time is anyone's guess, and what it would do to the rest of you is an exercise for the keen experimenter.
We are basically too active and too large to eat grass, even if we had lactase.
