Once upon a time there wasn't any commercial chicken feed. If you will do a search you
should find any number of old
books, free to read on the internet,, about raising poultry. Anything pre-1950s is likely to be of value. I've read several (just can't remember names) and they mention things like pouring
hot water over mash in the evening so it's well soaked by morning feeding time. Many recommend chopping fresh clover and mixing it in with other things like hardboild egg yolk for chicks. Also mentioned in old books is meat and bone scrap. Apparently you could just order it from the butcher, it was the fine meat and bone scrap from his saws and whatnot.
One of the biggest things is clean fresh
water at all times and grit. When I raise chicks I sprinkle a little of the chick size grit over their food from day 2 or 3, to make sure they are getting it. When they are bigger I start dumping buckets of sandy gravel in the pens. I will probably never have the space to not feed my birds commercial food but there are a lot of things that will cut the feed bill.
leftover
milk and whey (they say the birds can't digest the milk but I never had an issue with whey or buttermilk)
any garden greens and weeds. BEWARE of cut long grass, fresh or dried, they will slurp it up like kids and spaghetti and it will get balled up in their crop and eventually kill them.
any leftover meat, fat or bone from the house or butchering
earth worms; start any number of worm beds and harvest as a protein source
compost piles; built of food and green waste plus mixed manures and
wood chips I have kept a dozen or so hens very happy on almost no commercial feed, and laying eggs. It is work, having to turn, mix and remake piles every day or so. unless you can set it up to do it with a
tractor.
There are various things to consider when think about this. Is your goal to just have some eggs and meat for the family at the lowest possible cash outlay? Then having more birds that rustle their own grub might work best for you.
Selling eggs or raising broilers to
sell? Then you might want to go the most efficient route of feeding mainly commercial feed plus extras as they are available.
And of course there are dozens of in between situations. Look up Harvey Ussuray and his book for more ideas