In the old days, they would run the hogs in the lot and barn if need be to clean up after the cows. (Think corn and human digestion).
FDA or USDA or someone put a stop to that efficient use of resources; can’t be a grade A dairy if you run hogs behind cattle.
We fed grain in the milk barn to get the cows in and they wasted a lot. Used to have the owner’s boy shovel it up for me to take home to my hogs. I made him think I was taking it home to my kids- I told him “be careful and don’t get too much sh_t in it or my kids won’t eat it”.
LOL. Good one.