Another fast food one:
I was an assistant manager for an Arby's for a while after high school (so, around 1998). I always assumed that buns that went bad or stale were thrown away. Nope. The vendor would come and collect them, and the store got a partial credit back, because they were re-processed back into new buns. The bread plant would grind the old ones back into "flour", process it, then add that to the mix for new buns, limiting it to a certain % of the recipe.
They broke the cycle and started from scratch once a week, so they didn't put bread through the process too many times over.