Acres USA magazine had numberious poultry articles in the feb. issue. poultry plant profiles story listed plants and herbs to grow for chickens these are Catnip(repels fleas & rodents)
Chickweed a favorite of chickens,Comfrey a nutritious food 20% more protein than soybeans,Garlic for a (wormer)and ginger root.
Stinging nettles increase egg production and are fatting, mix with comfrey is powerful laying stimulant. other plants in article were
Alfalfa,nasturtium,Oat sprouts,rue,stinking roger pigweed &wormwood