This is not a article on feeding Icelandic horses. As they say on the net, IANAEN (I Am Not An Equine Nutritionist)(;->). These are just a few hints which I have found helpful. Just in case you get tired of reading these notes, I am going to give you my best hint right up front.
Feed your Icelandic horses like ponies
Do not CALL them ponies; just FEED them like ponies. If you are like me, you have had trouble finding information about feeding Icelandic horses.
Icelandic horses don't need as much feed as most other horses
Maybe I should retitle this note: "Hints On What NOT To Feed Icelandic Horses." They are easy keepers and easier to over-feed than to under-feed. When I got my first two Icelandics I went to several nutrition seminars hosted by feed companies. In only one did I find anyone who knew anything about Icelandic horses. His wife was a veterinarian who had visited Iceland. He said his wife was amazed at how little the Icelandic horses got by on. This hint was probably the most useful information I got at any of the seminars I went to.
Icelandic horses are physiologically different
I read somewhere that Icelandics have several more meters of intestine relative to other horses. I can't verify this personally but it is consistent with my experience. There was a article in the USIHC Quarterly a few years ago where the author said he fed his Icelandics 12 pounds of grass hay per horse per day. Any more than that just made more manure to pick up. If you estimate that the average Icelandic horse weighs about 800 lbs that would be 1 1/2 percent of their weight which is a good rule of thumb for horses not working very hard. The operative word here is "grass". I tried to mix 25 percent alfalfa hay with 75 percent grass hay in order to increase the protein and calcium content. My horses colic'ed. Straight grass hay for my Icelandics from now on. I feed a supplement to help with the protein and calcium/phosprous ratio. In the spring I get them out on green grass as soon as I can.
Feed your Icelandic horses like ponies
The famous horse trainer, John Lyons, produces a news letter called, "The Perfect Horse." A recent issue carried an article about feeding ponies. The article pointed out how cafeful you have to be to not over-feed ponies. The article suggested that some horse breeds such as Fiords, Icelandics and Morgans have pony like metabolism and should be fed like ponies. Wow! The light bulb comes on! That is the best advice I have ever found. You don't have to CALL them ponies; just FEED them like ponies.
My horses love beet pulp
If you live where they grow sugar beets, you can get dehydraded beet pulp pellets at a reasonable price. The "Perfect Horse" published an analysis of beet pulp a year or two ago. Basically beet pulp is fiber and can be fed pound for pound as a substitute for hay--not grain. I presoak the beet pulp for a couple of hours and it really soaks up a lot of water (about 6 or 7 parts water to 1 part beet pulp.) This helps to hydrate your horses. One pint (one lb) makes about 1 gal of feed and it gives them a "satisfying" meal. It also provides a convient means of mixing in salt, supplements and grain. My lactating mares and growing foals get grain (I read somewhere that a lactating mare produces 30 pints of milk a day--that takes a lot of energy.) For the older horses I add one cup (1/2 lb) of oats to the beet pulp mixture to add crunch and flavor.