Nice ly said George-- You solidified my thoughts in to something useful. Green are always good in addition to seeds. THis makes sense now. IMO when chicks can pick their food they take the softest, most tender, shoots. ANd look for the insects that abound in the greens.
What greens do you feed in the winter months if I might ask? Perhaps are region allows for fresh picked greens.
And yes, my ducks are master foragers. Grass for sure. And oddly they find leave piles and sift thru to get insects etc. They rather prefer the latter for most of their time foraging. Of course right now they all sit out on the rails, off the snow and waiting out the day.
I like Rape. It is easy, fast, and stays palatable longer. The birds like it. A little goes a long ways.
Rye is easy, but they can get too much. When it starts maturing and getting taller, I cut it.
Chickweed is abundant here now, and will be more so soon. My birds that are in their breeding pens got chickweed today.
Clover is good. I like shorter clover. The taller "stemy" clovers are better for grazers and browsers.
Chicory is great, and is a perennial. A little goes a long ways.
Dandelions.
I like to take advantage of what is here already as I can. If I where you were, I would have a bed or two that was a hoop styled greenhouse.