Here at The Natural Chicken I've been including lupins in the birds' diet so I can reduce the soy. Lupins (not to be confused with Lupin Beans or Lupinis, which are toxic unless boiled) originally had high levels of compounds that inhibited the absorption of nutrients. However most modern lupins sold in feed stores have been bred to have low levels of these anti-nutritional compounds, and are therefore safe to feed chickens or other animals.
In my chick grower recipe, for instance, I now include 5-10% cracked lupins which have been briefly soaked in molasses water. Lupins can be a little unpalatable when birds are unused to eating them, but a small amount of molasses helps overcome any reluctance. At anywhere from 28-42% protein (according to http://www.lupins.org/feed/) they really are a useful feed.
However it can be difficult, relying on vegetable proteins, to meet the full amino acid requirement of growing birds. Remember that chickens are not natural vegetarians. The easiest way to ensure a full amino acid profile is to include a certain amount of meat protein.
Since meat meal is a byproduct of slaughterhouses, it includes reject meat from carcasses that may contain higher levels of chemical residues than those allowed in human diets. This isn't ideal, and it's always worth looking at other sources of animal protein than mass produced meals.
The obvious ones, from my browsing, are mealworms, earthworms and other insects. I'm not all that keen on feeding my chickens maggots, because there are dangers of botulism if maggots have been feasting on rotting meat, but mealworms sound fairly easy to raise, and would make a terrific additional feed and protein boost for young chicks. (I don't raise them, so can't tell you how to do it, but if you google you'll find very detailed how-to's, basically involving lots of icecream containers and bran.) As for other insects, well, it's cicada season here, but I'm not sure I'm up to climbing trees.
What I'm currently doing instead is trying to set up a worm farm just for feeding chooks. A trip to Bunnings for $24 worth of compost earthworms (or 'redworms') was my only expense, as we happened to have a defunct fishpond lying around. With the addition of a lid and of course a heap of compost and scraps, my worm farm was underway. Naturally it needs to be in a shady place; this one sits about 45cm deep in the soil, and is made of concrete and stones.
It's too early to say what the production rate will be, much less if I can actually farm worms without killing them by adding too many lemons or other no-no's... Frankly I'm pretty ignorant about earthworms. But I will say one thing: with my preference for avoiding insecticides and coccidiostats, I would think the worms in this farm have a pretty good chance of breeding quickly.
Once I have sufficient numbers to start feeding chickens, there remains the question of whether I feed them to the chickens raw, dried or cooked. Cooking would remove any internal parasites (earthworms can carry tapeworm, for example). Drying would mean they can be stored for feeding at times when protein availability is low (or extra is needed, e.g. when chicks hatch).
But all this is theoretical unless the worms proliferate... So watch this space! :-)
Oops! One important reminder. If you do get into earthworms, remember never to put chicken droppings in the compost if your birds have recently been wormed! The products that kill intestinal worms also harm earthworms.
Meanwhile the University of Manitoba's poultry feed information pages are very useful for anyone starting to make their own feeds. Try this link for starters: http://www.gov.mb.ca/agriculture/livestock/poultry/bba01s12.html. And happy chicken feeding!