AIV? For wintertime dried fodder, if in an area where it grows well, alfalfa would be a great treat. You might also want to look into Comfrey, specifically Bocking #4. Regular comfrey is very invasive, but the #4 is sterile, supposed to be very high in protein. #14 is reputed to be better for compost additive. Both have very deep root systems and are expert at mining minerals from the deeper soil layers. Sprouts are a great winter time feed. I have started 2 Siberian Pea Shrubs. One of them is now putting on some good growth. They're both spending the summer in pots b/c I need to get some land cleared before putting them in their final resting place. There's also a potted apricot, 2 cherries, 2 elderberries to keep them company. I'd like to create an island of chicken friendly shrubs and plantings for their free range browsing.