They really do need a formulated poultry feed, vegetables and herbs don't have all the nutrients they need, especially protein and spinach can be bad for then. A flock feed is what will work for your birds.
Male ducks have wieners, roosters do not, if a male duck tries to mate a hen, he can hurt or kill her since hens aren't compatible. I'm sorry.
Is that they're entirely diet? Have they always eaten this?