These chicks are a week old and haven't eaten any commercial feed. My feeding regime is quite simple: after mixing up the adult hens' feed (sprouts, kefir, lucerne chaff, soy meal non GMO, seaweed, oyster shell, salt) I usually have a little too much. I add extra soy meal and also extra kefir, whiz it up in the food processor and that's my chick feed. The wheat sprouts are thus growing right up until the point of consumption by the chicks. Because they're sprouted the wheat kernels are soft and whiz up to a crumble very easily.
The amount of oyster shell in the base feed is only 1.5%. It's too low for the layers, but they have shell grit available in their pens all the time. Thus I'm not harming the chicks with too high calcium.
At the moment they're in the cold brooder (the one made entirely of wire). I was planning to slip these birds under a broody hen, but unfortunately due to a domestic disaster I gave away all my hens. I was going to give away all the chickens but things calmed down. Ultimately it makes no sense to pay $5 for stale supermarket 'free range' eggs if I can get better eggs in the backyard at lower cost, with just a little effort.
Having switched my children's diet to one containing more vegetables and less refined carbohydrates, I'm also happy to feed scraps to these birds. The kinds of scraps I'm talking about are vegetable/egg patties, mince patties, home grown greens and so forth. My dog is already thriving on scraps (with extra bones, meat, liver, etc) and her severe flea allergy of two years ago entirely disappeared when I took her off commercial dry food, so I know what a difference it makes to use fresh food.
The one thing I'm really learning as I make these big shifts (from industry-processed to home-processed; from fillers to fresh) is that feeding even very young chicks doesn't have to be a science. As long as the basics of both human and animal diets are richly varied, fresh and/or made into living foods with additions like probiotics (lactobacilli from kefir, for instance) there's a lot of room to vary. Of course, there are some crucial things to understand such as what range of seeds and feeds will provide the complete range of vitamins (you can't for instance just feed wheat and linseed/flax), but again there's no need to be out there with measuring cups and scales every day. Sprouted wheat, corn and peas, lucerne (alfalfa) meal or chaff, non GMO soy meal, sunflower seeds (ground for chicks, whole for adults), kefir, fresh greens: these can be used to make a whole feed at home.
The chicks are eating a ground crumble of about 60% sprouted wheat, 6% sprouted corn, 4% sprouted peas, 4% sunflower, 20% non GMO soy meal, and 6% lucerne chaff. That's the dry basis. To this I add about a cupful of kefir made from powdered skim milk, and of course a pinch of seaweed meal per 10 chicks, and a very small pinch of salt. Then of an afternoon I add finely chopped grass, chickweed, dandelion, spinach or other greens. As soon as they're out of this small brooder and on grass, I won't need to chop greens for them.
This is the same diet as the adults, except that the bigger birds' soy meal and kefir amounts are lower, and I'll usually increase the calcium by adding more shell grit to the bucket just before putting it in their feeding troughs.
When soy meal in this country goes the way of US soy (almost entirely GM) I'll of course be changing the feeds and probably going back to using meat meal. I might even find a way to buy fish meal, perhaps by forming a co-op with other home feeding chicken keepers to buy bulk amounts. Or I might do more gathering of protein around the backyard, e.g. by laying out carpets on top of grass and scraps to draw worms underneath, harvesting them of a morning.