Originally Posted by 1muttsfan
Actually laying stock Leghorns are carefully bred from stock that is developed by each chick supplier. Since white can hide a variety of colors, you could get a lot of unexpected genes in the mix. The AB's are a breed, not a hybrid, so outcrossing without generations of careful culling will not produce AB's. Certainly you could call them hybrids. None of the AB's I have had lay anything smaller than a large egg.
Outcrossing would also tend to dilute the blue egg color. These birds were developed by a poultry geneticist to have specific genetics, and outcrossing will certainly have an impact on that.
You are right they are very carefully selected (often hybrids themselves) for productivity by each breeder, much like "red sex links" have different formulas from each breeding program.
There definitely are hidden colors under the white, most commonly in my experience is Barring(used to prevent any black expression) in the two different sources of commercial Leghorn stock and of course black. I have also ran into an issue with red/brown leakage in cockerels, nearly identical in appearance to that of the U of A blue cockerels I have seen so far posted and in my own U of A cockerel. Not desirable for me, it still needs to be bred out.
That's great that you have larger egg layers! The first shipment I received was what I would call medium sized, smaller and lighter in color than most of the birds I currently have. The second shipment was slightly larger eggs, similar shade and fortunately for me packaged very well(Thanks Ron!).
Fortunately for us, the blue egg gene is relatively simple (a single dominant gene) compared to brown eggs which is determined by many many genes.
Edited by Manningjw - 9/29/15 at 5:01pm