Even if it doesn't have much mold,unroll it so no one cow can get to a whole moldy section to herself.I have seen cows go for certain types of moldy hay.They could overeat on it.
A few years ago,my neighbors baled "dry" hay one day and proceeded to wrap it the next.Didn't wait for the heat to drive out the little extra moisture and didn't bale wet enough to ensile.They had a lot of dusty,moldy hay.Fed some in rings and had one steer come down with ensephylitis.