If it's fresh, they'll vacuum it up in a very few days, especially if it's been dry and a lot of the browse is gone. I put bales in a couple of elevated cattle panel cages with a tin roof and a holder on one end for a mineral block. I found them on Craigslist down here. Keeps it above the hogs.
Earlier in the year I think I was sold some ancient bales at Kothmann's in Menard. They barely touched them, but it might have also been that there was more browse then. Still, I buy it by home. I figure the "horsey set" around me buys so much that fresh is coming in constantly.
It's a good attractant for axis, I believe.