The first thing to understand when you begin
to formulate your own chicken feed is that there are different types of
feed out there.  Basically, chickens of different ages or types
need a different ratio of protein and calcium in their diets.
Here are the top three types of chicken feed:

• Starter.  The
  starter ration you buy in the store is a high protein diet (usually 18
  – 20%) that gives your chicks a jump start on life.  Feed this to
  young chicks for their first six weeks.
• Grower.  When
  raising chickens for meat, you should feed slightly different amounts
  of protein as the chickens age.  After six weeks, lower the
  protein to 17%, and then lower it again at 15 weeks to 14%.  Of
  course, you can keep feeding the starter ration to your birds, but it
  costs more to feed the high protein diet, and your chickens may get fat.
• Layer.  The layer
  ration is for adult, egg-laying hens.  These girls can get
  slightly lower proportions of protein than chicks (usually 16 or 17%)
  but will need calcium added to their diets to replace the nutrients
  used up while making egg shells.

Of course, different breeds of chickens also need slightly different formulas.  In addition, time of year can make a big difference — many sources recommend feeding more carbohydrates (mostly corn) in the winter to give your chickens the energy to stay warm.

Stay tuned for homemade chicken feed recipes.