In my place, they say milo (grain sorghum) is great for laying hens. It's a beautiful plant to grow too. You should probably use it instead of buckwheat. Actually, milo is the true buck wheat, be ready to harvest both grain and venison! The modern varieties are much lower than the early tall ones, so you can spot the deers more easily.

Include normal wheat or barley in the mix too, and whether it's for eggs or meat, you should grow some flax, both fetch higher prices with flax, as they can be advertized as healthier. Drums of mealworms could add some cheap proteins, mealworms eat about anything and then some. Good luck to your enterprise!

Do you grow and raise organic, free range or confined?