http://www.thai-farm.com/feather-sexing-chickens/ Some folks try to use feather sexing on all chicks. However, it only applies to a select list of pure bred chickens. There are some mixed breed combinations that can make offspring that can be feather sexed as well, but genetics are not my thing. This also only applies in the first few days after hatch. I take this list with me when going to buy chicks.