Hey! Don't complaign about $5. horse quality alfalfa...lol. We're in Texas Panhandle and have good source of alfalfa with average of $4.50 bale over 4-6 cuttings a season. In Dallas/Ft Worth area, horse quality alfalfa goes for $5.50 to $9.00 a small 60-70# bale, depending on the season.
Anyway, cost of hay is cheaper than a horse. We feed about 3" flake of alfalfa 2X day, mixed with about 6" bermuda grass hay in winter. In rest of time on pasture grazing, feed about 2" flake of alfalfa 2X day. Also, feed small "pork & bean" can of either Purina Strategy or Moorman's PowerGlo supplement 1X day. (these are for each horse, obviously).
Agree with other post...watch or avoid grain hays and especially don't feed any of the Sorgram (species) hays. Also, be extremely careful of lush new growth on grasses and/or fescue grasses. Colic and/or foundering can occur. Never feed any moldy or dusty hay...check each piece before put out. Pregnant mares may require more food, depending on their weight status and condition. We don't ever feed any bagged type grains. We raise registered Peruvian Paso and Tennessee Walking Horses (as well as registered Longhorn cattle). Finally, make darn sure any hay doesn't contain even one or two Blister Beetles (can get into alfalfa crop during flowering)...blister beetle toxin is deadly to horses.
In sum, there is no substitute and peace of mind for QUALITY hay..."when you care enough to feed the very best". Bill