Why does it have to be corn that is fed to pigs? How about slop which is basically food scraps mixed with milk. Andrew Zimmern did a show about Las Vegas and featured a hog rancher who got free food scrap left over from the Las Vegas buffets. He boiled up the scrap and then fed them to the hogs who were later slaughtered and sent back as ham, bacon, and ribs to the same Las Vegas buffets where he got his food scrap. An endless cycle.
a few small scale feed lots can do this, but the big ones we rely on for the huge volumes wouldn’t work, the logistics would be too big to overcome. They feed corn and soy because it stores indefinitely, doesn’t need sterilization almost daily and is far cheaper to process than something that spoils in a day. We have some pig farmers around us, and if there was a cheaper or easier way to make a buck by feeding the pigs slop vs. grains they would do it in a heartbeat.
When I was a kid the garbage man was a hog farmer.
Our uneaten food became food for his hogs. Of course this meant that we separated our food waste from other waste.
This was a good deal for the garbage man. He was paid a small amount monthly for picking up the garbage and he paid nothing to feed his pigs.
We burned our other waste in a 55 gallon steal drum which was hauled to the dump about every other year.
It was a great system. Dumps could be much smaller and it was recycling that actually worked.