Another thing to ask the mill if they can't pelletize, is can they crack or crumble pellets? Pelleted alfalfa is a common horse feed product but it's too large (3/8") for a chicken. If they run it through the cracker, it ends up like a crumble. Alfalfa pellets are made from a lesser quality hay so it will have less leaves and be lower in Ca and protein but it's still an option. Another feed common in the horse industry is beet pulp. It the fiber residue of sugar extraction from sugar beets. It's mostly a high fiber filler feed but it's decent in Ca, protein, Fe, energy and has no sugar left in it. It comes either shredded or pelleted. My chickens clean up what the horse drops happily.