We like friendly birds and cull those that are not. We do some breeding in pens but also set eggs from our free ranging birds for the serendipity effect. For us understanding the genetics is fascinating and helpful in trying to back figure parentage. We are keeping better records now and understand more about what information we need for our detective work. Now that we know more about comb genetics it helps us in some cases to eliminate some possibilities.
Color helps some, ear color helps a bit.
What else can we use. I suspect that leg and beak color are not too helpful. The indistinctly barred feathers of Paz and Taz that are laced with straw and red brown respectively and unlike anything we have seen in any chicken pictures. They are striking birds and we are investigating getting a digital camera soon so that we can show them off on the web. I don't know why some birds produce this pattern and most do not.