Around here alfalfa is more expensive then the grass hay.
The particular group of vets that use it recommend that that is ALL a horse needs. The stuff they bring in and use tho you can't even find growing in the field here, let alone hayed. I've never seen stuff so dark green.
Becky
Some farmers here add a little bit of alfalfa to grass field if it's really bland. It's interesting that no one grows it there, because here, it's grown in Eastern WA, which I think has a similar climate to you.
The alfalfa hay we use here is all the horses need. Our working horses get grain and the brood mares get grain during the last part of their pregnancy. Well, by grain I mean Equine Senior or Strategy or Mare and Foal - whichever is applicable.