So what do chickens eat on pasture?  I started out my adventure assuming that a pasture for chickens was the same as a pasture for cows and other ruminants, but I was very wrong, for reasons you'll soon understand.

A good place to start when learning about chicken nutrition is with the birds' wild counterparts.  Most scientists believe that chickens were domesticated from red junglefowl (Gallus gallus), which currently live in southeast Asian.  There may have also been a bit of hybridization between the red junglefowl and their cousin the gray junglefowl  (Gallus sonneratii) when developing the domesticated chicken, but we'll stick with exploring the red junglefowl's diet here.

Neither kind of junglefowl is a vegetarian.  Scientists who cut open the crops of wild junglefowl discovered that more than half of the mashed up food therein typically consisted of insects and other invertebrates (especially termites).  Various plant matter was also represented, with an emphasis on fruits, berries, bamboo seeds, nuts, and young leaves.

Harvey Ussery sums up this information in a slightly different fashion in The Small-Scale Poultry Flock.  He suggests that we need to consider three food groups when nourishing our flock:

Sounds a lot like a healthy human diet, doesn't it?  If you think of the worms your chickens scratch up as shrimp, the grasshoppers they nab out of the air as beef, the sourgrass as lettuce, and the grass seeds as rice, then you'll realize your chickens are getting a well-rounded meal out of pasture.