[/img]Here is a picture of Henry Ahlf and one of his White Leghorns from a 1960's newspaper. It was Henry who told me many years ago to pick out your tall rangy cockerels and pullets late in the fall. It is the tall ones that make the best looking hens and cocks as they will settle (shrink) in height with age.
I always tell my customers to come back and stay with the bloodline,as having one line dominant in blood percentage will allow more stable breeding,you can add new blood at times,just have it blend with the original line until 3/4,before mixing with the rest of the flock.If you get eggs or chicks from a breeder,remember that you are getting only the genetics of the birds laying at that time.Perhaps in another few weeks a different group of hens may be laying instead.My point is the breeder may have just the birds you need with just the traits you want ,within his flock or gene pool. The reason some birds mix into (nick) well, is similar genes,which usually means related.When outcrossing to cold blood you may get genes that are either dominant or recessive,maybe both,so they may not look good.The genes you want may be hidden,so stay with an outcross a few generations to see the genes re-appear.Backcrossing to the original line works best.I cull all the cockerels from a f1 cross of new blood plus the original nnew blood bird,that way my original blood can be maintained in a high percent. I hate to sound like a skipping record,over and over,but so often people think they have to make there own strain (in time you do this regardless even staying within a bloodline) ,so they cross this line with that line and those again to yet another.This method really stirs things up and it is a tool that should only be used by the most skillful breeders for a certain purpose . What purpose? Well as a last ditch effort on a rare breed that is in very poor shape with only inferior specimens,you could mix them all up from several sources and hatch lots.Perhaps in some birds traits will resurface that are hidden or recessive,allowing these trits to be identified and selected back out.It would take several more generations to re-set the traits,but it could save a gene pool.
Perhaps this should be posted on the rare breed thread,but it has worked before and might be worth a try on some bloodlines,I am thinking of countries that Buff Leghorns are rare or run down and importation is not an option.