Plants for poultry

I am thinking of planting a few trees/bushes/guilds in my poultry yard for the chickens and quail. I want to plant mulberries, siberian pea shrub, and small acorn white oak.

I have read that mulberries are high protien and can feed chickens almost with a complete diet. Persimmons might be an option but they hang on the trees for too long and I don't think my poultry could forage them. I would like to have some that attract insects as protien suppliments.

What else would be a good idea to plant in a rotated poultry pasture. There are going to be 4 plots that the poultry are released into consecutively so that they do not destroy their yard.

Would nanking cherries be an option? What about underplanting (clover, alfalfa, chicory, are what are currently being planted).

What do you think, what would be the best for poultry flocks.