The nutritional balance of hay may or may not be a good idea. I' d check with your state wildlife biologists. There are definitly ways to help but this advice should come from a specialist.

We put out two mineral licks for deer and elk this year but the formula was designed by a Wildlife Specialist to provide the rumanants with nutrutional supplements that help them grow in every way.

So DO IT but check first to make sure you aren' t doing more harm than good.