I found this online and though it was interesting. Anyone know which chickens are fast or slow feathers, though? *haha* "Feather sexing became possible in 1969 after several years of genetic research by the Tegels Poultry Breeding Company. This method used to determine the sex of newly hatched chicks is only possible if a female from a slow-feathering breed is crossed with a male from a fast-feathering breed. The sex of the chicks produced from this cross can be determined during the first 48 hours after hatching by looking at the primary and secondary feathers located on the chick's wings. The primary feathers will be noticeably longer than the secondary feathers on a female chick. On a male, the primary and secondary feathers are the same length. "