The way the blue egg genetics are inherited is as follows:
1) [Blue/Blue] x [Blue/Blue] = 100% [Blue/Blue] --> 100% blue eggs layers
2) [Blue/Blue] x [White/White] -> 100% [Blue/white] --> 100% blue eggs layers
3) [Blue/White] x [Blue/White] -> 25% [Blue/Blue], 50% [Blue/White], 25% [White/white] --> 75% blue eggs layers, 25% white egg layers.
Note the CLB's that are laying light tan eggs are the result of #3.
a) Blue + White = Sky Blue
b) Blue + light tan = Minty Green
c) Blue + light brown = Green
d) Blue + dark brown = Olive
The Cream Legbar lines in the USA produce a Sky Blue to Minty Green color eggs. Selection for Sky blue eggs will maintain this color. I have heard that there are dark brown genes that are recessive. I don't think that any recessive dark brown genes are in our Cream Legbars. I am not aware of any olive eggs poping up from pure CLB lines in the USA, but should this happen, then the breeders should breed the gene out like any other defect or waekness they find in their line that isn't supposed to be there.
Thank you Gary, when trying to explain possible genetic expression it helps to write it out, since there are some that can't follow a Punnett Square. I do understand what you're saying, however the British SOP allows for olive eggs. While the SOP you and others have diligently works on does not allow for olive eggs, I cannot in good conscious call it a defect, since it's known in the breed in it's parent country.
I read this whole thread, and I am in the process of reading the main Legbar thread, and I am almost sure that someone did get eggs that were more olive in in color than mint green, I can't recall whom or when, since I finished reading the main Legbar thread a couple weeks ago, and I am still in the process of reading the main Cream Legbar thread, and for me, that's over 600 pages of information rattling around in my brain.
If the Cream Legbars that are laying light tan eggs are the result of [Blue/White] x [Blue/White], where is the light tan coming from? White egg is a recessive. Of course there are modifiers at play that contribute to color saturation, but I'm not sure where the light tan you're referring to would come from.
Talking about the roo right above.
Cockerel questions:
1. What do you think of this guy? (He's about 20 weeks old.)
2. Given that he hatched from one of the two known (as far as I know) light-brown-egg-laying Cream Legbars in the U.S., would you sell him as a breed-unspecified chicken? Or a suspect-lineage (egg color) Cream Legbar?
If those two hens are straight from GF, then obviously there was some crossing done at some point prior to importing, or prior to public sales, since they're brown laying Cream Legbars, and if the gene is in those two hens, it could well be in their sons, who would then go on to produce olive egg daughters. This is not to mention whatever birds in the line they came from themselves could carry those genes. This is especially possible if they are straight from GF.
Off the top of my head, I could surmise that at least one of the birds imported came from a crossed line, making it [Blue/White] (sorry, all I can recall is the blue egg gene is O). If this bird was bred to an olive layer (or son of an olive layer), which is allowed in the British standard, and the white gene was passed on with the brown gene of the olive layer, that would possibly be the cause of these two known brown laying pure Legbars. And I would think it would more likely be a son of an olive layer, since an olive layer would be known when she laid her pullet bullet.
Or in other words [Blue/White] x [Blue/Brown] = [Brown/White] = "pure" brown laying Cream Legbar.
And I have to interject and explain that pursuant to the known differences in color perception, what I may be calling and recalling as olive may well be what you have described as green, aka blue over light brown, not blue over dark brown. But again, olive is known and accepted in the breed standard in the UK, as is green, so the genes for brown eggs are in the breed to some extent, already making the possibility of brown layers possible, especially if there was a cross to white layers as I think I recall, which was done to increase egg production.
Now, I'm the first to say I am new at chickens. But I am not new to genetics, and I work with them every day, especially simple dominant/recessives. I do not have much hands on experience or practical knowledge when it comes to chickens, but I am a sponge, soaking up everything I am reading and learning about them. Until I have and can work my own flock, I'm enjoying learning as much about this breed as I can, as I have decided that it's going to be my first breed (I have my eye on three more, but the Cream Legbar is going to be breed one).
So when I see something that makes my journeyman geneticist take note, I have to find out more about it, to make sense of it, especially when what is being said seems to fly in the face of what has been said, current knowledge, and known information about that subject.
I found it curious that olive layers are being said to not have been imported, yet there are known brown layers, and this is a blue laying breed, so how do we reconcile these things?
Now isn't that interesting--the splotches look more spot-like on camera and they look over-all a tad darker than in person!
