DIY Feeder for Horses. Doesn't look too difficult to make, and I'd probably add some type of covering on top.
Slowfeeder ...another great idea! Keeps hay dry, easy to move on wheels, and perfect to set up in several locations. I think this would be the perfect solution for a couple of horses!
Barrel Feeder. Maybe webbing on front instead of metal
DIY safe tractor tire hay feeder, so doing this when we buy a house
DIY pasture hay racks More
Recycled horse feeder---my new planter for the veggie garden.
Build a Low-Cost Hay Feeder | Smart Horse Keeping | TheHorse.com
Slow Hay Feeder
idea for horse mineral feeder