Also, watch for foxtails. Some people don't have an issue, but the barn where I used to ride had a BIG problem last year. The horses started getting sores in their mouth, colic, etc.. they couldn't figure out what was wrong. 2 horses ended up dying of colic. After that, the USDA came out. Took one look at the hay, held up a foxtail, and said 'there you go.' The horses had to have their mouths washed out.. had to have special mashes daily. After 2 weeks on good hay, their mouths healed, and they could be ridden. It was scary, though.