Looking for some ideas myself and thought this one was interesting.  I found it at;

 http://paddockparadise.wetpaint.com then click on slow feeder

or google slow feeders for horses and there's some more there.

Slow feeders have been an interest for awhile now. I have built alot of different designs and good sucess with some. I have two favorites, one is a wood box that sits on the ground the other is a barrel that hangs from a post or tree. The wood box is about 18"wide 18" tall and 48" long. It has a wire grate with around 2" x 4" openings that fits in the box over the hay.

http://vimeo.com/6973723

This is the barrel design, it is a pickle barrel. It hangs from the lid which can be lowered to the ground. I now have a slow feeder hay net stitched to the bottom of the barrel and it works good.  My nets will begin to wear in about 6 months with 4 horses on it 24/7. The hay net hangs lower and is easier for them to get at the hay. There is some waste that falls to the ground but not too bad.

Lee

I cant find a picture of the box feeder so I drew a quick model. My apologies it is not exact, the wire mesh is not diamond like in the drawing. The lid is a 2x4 frame with hinges on one side and a latch on the other "not in drawing" . Also my previous measurements were wrong, the box is more like 4 feet long 16" tall and 18 to 20 wide.

the hay goes in, the wire mesh frame goes on top of the hay and then the 2x4 lid/frame is closed. As they eat the hay the wire mesh just fall to the bottom of the box.

saltwater redneck,

That Appaloosa is gorgeous!!! Liked the barrel feeder too!

I am wanting something that I will put in the stall to keep out of the weather. I like that box idea with the hog wire? That was was I was thinking more of.

Thanks!

thanks, that one is a handful.

You could make a smaller box version that holds less hay. I put the wire in an angle iron frame to get rid of the sharp edges and add weight. Make sure the mesh is small enough that if they stand on it a hoof cant fit through the hole size. I like the 2" by 4" mesh that Tractor Supply sells. It is a heavy gauge that hold up and will weld to the angle iron frame easily. I will still try to get some pics for everyone to see.

Lee

Ran across a picture using two tractor tires for a hay feeder http://axeholmeshires.com/tirefeeder/

Also a picture of a barrel idea, http://thehorse.com/blogs/smart-horse-keeping 

Thanks for this link,through it,I found the Natural Hay feeders for pasture use with square bales,I got in touch with the closest dealer who is working with us on delivering these at a halfway point,no charge!

I went for a ride with some new folks this week.  As I unloaded at his corral I noticed his feeder and I'm going to have to make one.  He feeds the 3x3x8 and the 3x4x8 bales. Which is the same size bales that I buy my hay in.  I've been flaking off a flake of hay and feeding it in a manager twice a day for the 4 horses. But with this feeder he loads a full bale with his tractor and it last 7-10 days for his 4 horses.

His feeder was made by Iron shop.  It was tube steel welded together. Basically a platform 1 foot off the ground. with enough steel tubes acting as balluster to keep the horses from climbing in.  The four corner bars supported a roof about 8 foot high that kept the hay under it dry.  He had a swing open gate on the side facing the direction the tractor would approach.  When he needed to load new hay in, He would open the gate and slip a new bale of hay in with his tractor and close the gate back.  He had a large corded net hung from the roof that covered all the hay, It was fastened along the edges of the platform so the horses had to eat thru the net and couldn't get their noses under the edges.

The horses just picked at the hay thru the net and had self regulated after some use so as to not over eat. Now instead of having to feed twice a day,  He loads the hay bunk once a week. If he sleeps in or is out of town for a day, The horses still get fed.

Since I've converted to the large square bales. this looks like a great solution. Hay stays dry, horses have constant access to feed, It's large enough that all 4 of my horses could eat at the same time and not get chased off by the alpha horse. Since I'm not an iron worker, but a carpenter I may try my first feeder out of wood.