have a look at all the ingredients in ForageCakes, the more obscure things like dicalcium phosphate and what-not, those are in there, in part, to get the calcium/phosphorus ratio balanced. Bone meal (steamed) is something that can be used for this. Sustainability issues aside, I've used this while searching for more appropriate/sustainable source.
Check out Fertell's "Poultry Nutri-Balancer", as well as Redmond Conditioner. Even if you don't use them, you can glean information from their literature.
Also, the spices listed in the ingredient list are worthy of consideration; paprika, turmeric, cinnamon, as well as red pepper flakes.
Side note: my eggs are costing me around $4 per dozen in feed alone. I quickly dropped all my production birds and became strictly a conservation poultier as my feed formula got more and more expensive.
Another side note: I've seen/cured three different flocks of the feather-picking madness after their owners kept them on an inadequate homemade diet. It happened in my own flock for a little while, until I started using peas. My own problem initially was with too much wheat, which contains a lysine inhibitor. The generally recommended inclusion limit for wheat is 30% and peas are a good source of lysine. The fish meal gives you your methionine. This is another area where I have to put sustainability on the back burner in the interest of the chickens' nutritional requirements.
In addition to "inclusion limits", also look for "anti-nutritional factors" or "ANFs" in your reading.
If you get it down, you and your chickens will be very happy. But once again, proceed with extreme caution and keep in mind that nature is not always a perfect guide in this territory, as there isn't really much "natural" about a domestic chicken. Wild (feral) chickens most probably do not lay 5-7 eggs a week.
