My neighbor inline wrapped some oat hay bales for me last summer that are just beautiful feed right now.  The oats had started to head out but not completely.  He puts 8 wraps of "Sunfilm" on them.  His wrapper did work better with 60" diameter bales than the larger ones I had made in grass earlier. No spoilage and the stuff smells very good as I remove them from the line.  Zero spoilage that I can see. No additives.

I was concerned because it was several days from baling to wrapping. They were obviously too wet to last as dry hay.  My cows really prefer the oat baleage to the dry alfalfa hay bales. Softer on the mouth I guess. The alfalfa seems sort of stemmy. I've been feeding one bale of each at the hay shed.

Jim