Protein is an expensive feed ingredient. So studies have been conducted to determine how much protein various types of poultry need at different points in their life.
Your chickens can eat the game bird mixes with no adverse effects, they will metabolize what their bodies need and pass the rest.
Game bird feed are expensive feeds to be fed to chickens. It's more intended for ....well, game birds and turkeys benefit well from the higher protein when the poults are growing out.
I have my own methods of taking care of and maintaining my little flock of egg-layers. My birds get a mixture of Whole Grains, recently though, I have gone back to adding supplementary rations.
Here is the traditionally suggested feeding of chickens.
Starter Feeds
Newly hatched chicks ages 0-10 weeks should be fed a chick starter diet with a protein level between 18%-20%. These rations are formulated to provide proper nutrition for growing baby chickens. Higher protein starter rations (22%-24%) are reserved for meat birds such as turkey, quail and pheasant. This higher protein level maximizes growth for broilers and roasters, but is not necessary or desirable for egg laying chickens.
Grower Feeds
At 10 weeks of age, a grower feed should replace the starter feed. Grower feeds are typically 15%-16% protein, and are designed to sustain growth to maturity. The higher protein content (20%), in starter/grower feeds is recommended for growing game birds. (and Turkeys)
Layer Feeds
Layer feeds are designed to provide optimum nutrition for birds laying eggs for consumption. Layer feeds contain 16% protein and have increased levels of Calcium, for proper shell development. Layer feeds should be fed starting around 18 weeks of age, or when the first egg is laid, whichever comes first.
