I have always given my chickens a flake of alfalfa once or twice a week. They love to scratch it apart and pick out all the little leaves. Mine also have access to the oat hay my goats eat but they don't seem as interested.
On really cold days in the winter I soak a block in warm water and give it to the ducks. They love it. Haven't tried one on the quail yet. I imagine if I just gave them a hard cube they would pick it apart slowly. Hummmm.... NOTE TO SELF: Get more alfalfa cubes!
During the spring and summer my chickens have access to grass and alfalfa in their runs. In the winter they are pretty much out of luck with greens so I give them a bale of alfalfa every couple weeks to pick through. It also helps the smell in the barn. It goes from "I should man-up and clean up this pen even if I have to pull my wagon through 2 feet of snow" to "hey, maybe this deep liter method will work after all with the addition of some greens".