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- #21
Thanks for your input. You brought up some interesting observations I could see. For one, you mentioning the white gene of the leghorn. I have a leghorn, and I see it. My svarts are from two different blood lines, and one was white, the other was tinted. The oddities of landrace breeds. The ones that lay white, are no way as flashy white as my leghorn. But then again, svarts are glossy and the leghorn is matte. In the same manor, we raised true bbs Ameracaunas last year, and got pretty blue (gloss) eggs. This year, we got a few Cream Legbars (matte due to leghorn genes), and I couldn't believe how blue they eggs were. They look like they glow blue.The genes you are working with are brown egg, blue egg, and white egg.
In your breeds, the only blue is the South American variant of oocyanin. It is a dominant gene meaning that any hen with one copy of the gene will lay a blue tinted egg.
I was able to identify 3 separate genes that produce white eggs. The most desirable is the intense white as found in leghorns. The other two genes produce a washed out version of white egg shell. This does not mean that there are only three genes involved, it just means that I was able to pick out results showing at least 3 are out there in different breeds. It is important to understand that all chicken eggs start out white and are either tinted blue by the oocyanin gene or are coated brown by porphyrin.
Brown eggs are a whole nother ball of wax. There is an entire biopath dedicated to coating eggs with porphyrin. All chickens have the porphyrin biopath, but in breeds that lay white eggs, it is interrupted at one or more places to turn off the brown coating. A study of the literature showed at least 7 different genes in the porphyrin biopath with mutations in at least 3 producing white eggs. A chromosome translocation with a lot of undesirable side effects is one variation that produces white eggs. If you are crossing a green egg layer with a white egg layer, you will wind up with segregation for some brown egg layers, some white egg layers, some sky blue egg layers, and some olive egg layers. The ratios I got were 8 brown, 1 white, 1 sky blue, and 6 olive. The number of chickens I raised was not high enough to confirm this as a verifiable and repeatable result so use this with caution.
IMO, after about 4 or 5 generations of selecting for oocyanin, it would be a really good idea to dna test for the blue egg gene and try to identify a couple of homozygous roosters. Why? If a rooster with two copies of the blue egg gene mates with a random group of hens that all lay blue eggs, the next generation should all lay blue/green eggs and about 5/8 should be homozygous for the oocyanin gene.
Also worth knowing, if you combine a white egg gene with a blue egg gene, the result is sky blue eggs. In other words, with the porphyrin biopath disabled, the eggs will not be coated and will not appear greenish/brown.
As for figuring out future egg colors, I had an anomaly with my Silverudds. New layers started laying and I got a beige egg. I new which one did it because I saw her laying it. About 20 girls into breeding these beautiful green egg layers I found a dud. I then noticed her red earlobes, unlike all the others. I went on line and found a few breeders that stated this happens from time to time.
I know I will learn a lot over the next few years with this. Thanks again @DarJones