I have read that too, so asked at feed store he disagreed. So I give my rabbits a tray every night ( for the group)that's how I reward them for going in when called. They are in a colony and free range between their shelter and yard all day. I say " bun buns time to go home, treats" they come running
I also free feed pellets and hay. Piles of tree trimmings, garden goodies. I also will pull whole sunflower plants for them, seed head, root and all. I notice on days they got a big seed head in the yard to work on they don't eat all the BOSS at night ( usually every last seed gets eaten) so they self regulate. In more than 70 rabbits I have raised I have only had one fatty.she had lived in a cage. I believe good food, good exercise, and freedom to choose makes happy, healthy rabbits. Aria just delivered her first litter (11)