I have no grass in the chicken yard, which is a 20' x 30' old garden area. So every few days I have been throwing a flake of Alfalfa hay in for them as they love the green leaves, being that there is no natural plant life growing. (The MINUTE a blade of grass makes it's appearance, it gets nipped right off.) And they have no interest in greens like lettuce and such. Is Alfalfa hay toxic to them? Is it ok to feed every few days? Thanks all.