Laying depends on both temperature and hours of light-pullets-very young layers should only have no more hours of light than 12--artificial light on mature layers will cause them to lay more-but some say this forcing them to lay more--unnaturally--even to the point of shortening their life...
try Amazon for books--21st Century Poultry Breeding by Grant Brereton--referred by breeder of BLRW Foley-I understand color -but then he goes into feather patterns
21st century poultry breeding--the gold cockerel series--by GRANT BRERETON- an in depth guide to how plumage patterns work--this is a very interesting book--
Many people do not realize the amount of time & money-I keep track of my chick prices & my feed bill-When I sell I always put---PRICES INCREASE WITH DAYS OF FEED & CARE--No matter what price I said -most people reacted with-that's too much--or they would call -I'd quote a price-then they might...