I have 3 Welsh Harlequin ducks, 1 male and 2 females, who are at least 7-8 months old. One of my ducks has a slipped tendon so she only uses one of her legs. For the last few months it seems like they will not gain weight. Both my females feel bone thin, I can feel their sternum and some ribs. They get fed premium food, it's called Organic Soy Free Stratch and Peck Layer feed and I mix it with start and grow feed. For some reason I can't get them to eat veggies or eat in the morning, only at night. What can I do to get them to gain weight?! :-(. Please help!!!