This posting has gone viral.
Everyone raises their chickens differently.
If you free range/pasture most of the day this will dramatically change nutritional needs. Especially depending on the quality of range.
Chickens will initially use the live food(insects, arthropods, worms, etc.) then the greenery and seeds. Given enough space and quality forage, much of their need can be satisfied.
If on the other hand they're penned most of the time, which is the case with most people, then the protein, calcium, etc. recommended %s need attention.
A neighbor called a couple weeks ago wanting to buy pullets. He said his birds quit laying. 30 birds were giving him 4 to 6 eggs a day. I asked what kind he had, how old they were and what he was feeding.
He said they were RIR about a year old and he fed them corn ONLY.
I told him they were starving and wouldn't sell him chickens until he switched to a complete feed.
I think I straightened him out.
I've since sold him POL Australorps and Brahmas. Then I sold him Ameracauna and Welsummer chicks. He's very happy now.
My birds produce an average 8.5 eggs per 10 hens from around 12 different breeds year round unless moulting. Granted they are for the most part high production breeds that are in my signature.