A friend of mine has five horses on Vashon Island and she is struggling with hay prices. She told me that she is currently stock piling as much hay as possible because of the rising costs. She's also had to pay for a new shelter to house the hay and keep it dry in the Pacific Northwest climate.
She told me that part of the problem is that so many fields are being turned over to corn production for ethanol. Hay is in short supply and costs are rising. While she'll probably be okay, it's the horse rescues that will be in serious trouble.
Here's an article about hay prices and how owners who can't afford their horses anymore are sending them off to slaughter. Slaughter where? To the hell holes of Canada and Mexico.