Methods of utilizing light during incubation of avian eggs to influence characteristics of avian pre- and post-hatch. Specific amounts of energy are provided to incubated eggs through a light source, having particular wavelengths, to accelerate embryo development and promote myogenesis post hatch. Green, red, or blue wavelengths of light, or combinations thereof, are provided to eggs in a temperature controlled incubator to increase myoblast and satellite cell production in avian eggs. The light can be administered to avian eggs in a manner that entrains an embryo's circadian rhythm in the egg.