My horses are on 20-80 acres depending on the season. They normally have 24-7 pasture access. I supplement as needed with Alfalfa pellets, BOSS and some Beet Pulp. Cheno, my old Appy gets the big portion while the others each get a bit so they dont' feel left out. Winter I up it accordingly depending on the weather and their condition. They are fed prairie hay as well as pickings in pasture all winter. The App gets Corta Flx and MSM.
I am planning on trying him on Kool & Kalm this winter as it's said to help rebuild lost condition. http://aussielogic.com