I occasionally still feed some small square flakes into mine. It does not have the extra "hay feeder" spike wheel kit to pull it in so it's slow and kind of a pain in the butt. I'm way too impatient to even attempt cramming bulk hay off a round bale into one, but it could be done.

I don't know if it's feasible in your area, but if you're just looking for an easy way to add roughage you might consider ear corn. I ran my last load of the season last week. The cob and husk work really well for me, especially on weaned calves. In a perfect world, I'd find a way to never run out of ear corn.