Baby chicks are taught to forage by their mothers and eat everything from grass to bugs, but when you are raising them away from a flock, prepared feeds are best.
Chicks raised within a flock by a mother hen are trained by the hen to eat what she eats. Generally, baby chicks will forage for grass and weeds, seeds, small insects and small pebbles or dirt.
When a mother hen is absent, it is best to feed chicks from a day old to six weeks with a commercial starter/grower feed. It is best not to provide additional foods during this time to ensure that the chicks are getting the full amount of protein they need to support their rapid growth. From six to 18 weeks, chicks should receive a commercial grower feed that can be supplemented with treats. Always keep fresh water readily available.
After six weeks, supplemental greens such as lettuce, kale, chard or grass can be given in small amounts. Small insects such as crickets or mealworms are a good source of additional protein. As you start to feed chicks treats, they should also begin to have some grit to aid with digestion. Scattering a little on the floor of the brooder or coop will encourage scratching behaviours.
Scratch, a combination of grains, is a common treat for chickens. Baby chicks should not be fed scratch until they are fully feathered and able to be outdoors. Keep in mind that scratch will raise a bird's body temperature and should be used sparingly in hot weather. It should be treated like candy for chickens and not provided as the sole source of nutrition.
To raise organic chickens, purchase only organic feeds. These feeds will not contain a coccidistat, which will require additional vigilance on your part to prevent chicks from becoming ill.