Oh - my buddy used to work overnights at a food processing plant in the summers to afford university.... His job, take all the bread that came back from the grocery stores, rip the bags open and throw them in the hopper of the industrial toaster that started the breadcrumb process.
Not to say all the bread was moldy, but plenty was..... It was the bread that came back that didn't sell before their expiry.... My buddy would describe a lot of what he'd throw in had a rainbow of mold colors on it.