This is the recipe I have had the most luck with.
Mixed in hot water and soaked for at least 4 hours
4-6 cups alfalfa/timothy cubes
2-3 cups beet pulp
2-4 cups rolled oats (molasses free)
Just before feeding add:
2 cups Hoffman's Horse Ration or Vita Stress or a Senior Mix

I feed it twice a day.

Some people like to add molasses also, I don't, as it adds too much sugar for my liking.

Free choice grass hay, free choice mineral and free choice salt

I can not stress enough to make sure the beet pulp is soaked completely!!

http://standardbredhorses.yuku.com