Cut and carry chicken feed, how to get a balanced diet, how to store

So, I'm going to be raising chickens, and as I was painfully threshing out some grain I had grown, I though that I could just throw it to the chickens. The grain would be picked out and the straw would become mulch. What combination of grains, seeds, etc. could I grow that combined with bugs, grit, and some greens would provide a balanced diet? Sunflowers and rye grow well here, so I would like them to provide the base if possible.

Question 2; how would I store this stuff so that mice and other critters don't get it? I know Europeans used to store grain in ricks; how did this work as far as rodents? My trial grain crops were rapidly consumed by mice, squirrels, and birds while awaiting threshing under my porch.

So Rye could be a part of the feed but something like Wheat and/or Barley should make up a larger part.  Peas and oil seed sunflowers could round out the mix.  Oyster shell lime and kelp are good mineral supplements.  I like to grow chia seeds and I just throw the seed heads in with the chickens.  A pre-mixed vitamin and mineral supplement could be good too.   You would need to approximate the amount of each that you are giving in order to make sure you get the percent protein right. this link might help:
http://www.avianaquamiser.com/posts/Protein_content_in_chicken_feed_ingredients/

I like using galvanized metal garbage cans to protect chicken feed from critters. Defunct freezer or refrigerators are easy to get a hold of, stand up refrigerators could be used laying on their back; they are insulated and pest proof.

Small grains were traditionally often kept in the sheaf and made into stacks.  On a raised, round platform, the sheaves would be placed, grain side inward, around and around and up and up.  Thatch the top to shed rain.  The platform would have broad, flat stones or (a more modern incarnation) metal pie pans on each supporting leg to prevent rodents from climbing and gaining access to the grains.

You could also build a simple granary, also raised, and store the loose grain "hay" in there.  Or convert the rafter space in a shed into a haymow.

And keep cats around.