Not the shade of blue

[angora831]

I have looked back in the ABC Forum for the topic of blue egg color.  I am looking for the genetics of the blue egg color and don\'t want to get into the discussion of what shade of blue we need for the breed.  What I found from other sources is that the blue color in eggshells is dominant to both brown and white.  When a blue is crossed with brown both contribute to the color of the eggshell and any shade of green, olive, etc can occur.  I also know that the brown color can have up to 13 other modifiers working on it\'s  shade and it has been suggested that white shells may also have these modifiers at work since there are several shades of white.  What I did not find mention of was the fact that these modifiers could also be at work on the blue gene present in our breed.
I doubt that it is this easy but, if we are getting eggs from our birds that have any tint of green/brown in them, does it then follow that our birds are not homozygous for the blue gene?  If this is true and we were to breed two hetrozygous birds together we would get a 1:2:1 ratio for the chicks in the F1 generation and work from there to rid the line of any brown influence?  Probably not that simple, eh?

Ken

[Mike Gilbert]

I doubt that it is this easy but, if we are getting eggs from our birds that have any tint of green/brown in them, does it then follow that our birds are not homozygous for the blue gene?  If this is true and we were to breed two hetrozygous birds together we would get a 1:2:1 ratio for the chicks in the F1 generation and work from there to rid the line of any brown influence?  Probably not that simple, eh?

Right on, it is not that simple.  The O gene responsible for blue shell coloration is inherited independently from the modifiers.  That means the modifiers work WITH the O gene to express any particular shade of color.  It is a blend, not one or the other.   Since there are so many modifiers, some being dominant, some recessive, it takes years of selection pressure to establish a line that always lays true blue eggs.
And there are so many other important things to select for that I don\'t know as that is practical.  If I were to start over again (some 35 plus years later) I would use only white egg chickens to develop the various colors, and worry about the ear lobe color later.   There are very few chicken breeds with red lobes that lay white eggs.   The black Crevecoeur is one, the Holland is another - if you can find them.   Hindsight is always 20-20, but the disqualification for white in lobes does not seem so important compared with the trials of establishing a line that lays only true blue eggs.   Here is a link that explains the blue shell chemistry.
http://ps.fass.org/cgi/reprint/85/3/546.pdf

[jerryse]

I agree with Mike.White eggs are the only way to totally remove green from the breed.I also would  use white eggs if I were to start over.

[angora831]

I was just trying to get my head around the genetics of the trait.  That is all, nothing more.  I agree that there are so many other things to work on to improve the breed.  I like the saying that I read somewhere... build the barn first and then paint it.   Pretty wise man there.

Ken

[John]

For those of you that like analogies...
I look at it as if blue and white are the only two egg shell colors and they are like vinyl siding on a house.  The vinyl is the same color outside, inside and thru.  A pure white or blue egg shell is the same way when no brown modifiers are added.
I think of all those modifying shades of brown like latex paint.  It doesn\'t penetrate much like oil based paints, but it\'s just a covering on the outside.  Of course if you put latex paint on the outside of the vinyl siding it will make white siding look tinted or some darker shade of brown depending on both the shade of paint and how thick it\'s applied.  That layer of latex on the outside will make the inside color of the siding or shell look a different shade also.
About the only difference with blue eggs is the brown coating combines with the blue to make the eggs look some shade of  green instead of brown.  
When the inside and outside of a dry shell are the same color of blue or white I believe you have an egg without any of those many brown modifiers.
That\'s the color I\'ve selected for, but maybe a little \"tint\" added to the blue is really desirable.  It may not be \"pure\", but it sure is a prettier blue.
 

[Beth C]

When the inside and outside of a dry shell are the same color of blue or white I believe you have an egg without any of those many brown modifiers.

That\'s kind of what I was thinking, so I\'m glad to see someone with a lot more experience confirm it. I don\'t get too wrapped up in egg color, but figured if the brown pigment was on the outside, then the color on the inside was what I ought to be shooting for.

Now, how do you figure out if there is white, besides waiting for a white egg to pop up & test-mating? Does white modify blue (i.e. create a lighter shade of blue/dilute the blue?) If I\'m understanding what I\'m reading it doesn\'t, it\'s a recessive and pops up when 2 bump into each other - is that correct?

[John]

Now, how do you figure out if there is white, besides waiting for a white egg to pop up & test-mating? Does white modify blue (i.e. create a lighter shade of blue/dilute the blue?) If I\'m understanding what I\'m reading it doesn\'t, it\'s a recessive and pops up when 2 bump into each other - is that correct?

I believe the only way to know for sure is wait \"for a white egg to pop up & test-mating\".  
Even though blue shell color is dominant to white I think it is like muffs.  If a bird is pure (homozygous) for muffs they are fuller than those on a bird that only has only one gene (Heterozygous) for muffs.  It\'s a double dose effect.
Some blue eggs are so light they almost look white.  Maybe the hens that laid them carry one gene for blue (O) and one gene for white (o) shell color.  If that is true we can try to avoid white eggs from popping up by selecting the bluer eggs for hatching and compensation mating.

[Beth C]

Even though blue shell color is dominant to white I think it is like muffs.  If a bird is pure (homozygous) for muffs they are fuller than those on a bird that only has only one gene (Heterozygous) for muffs.  It\'s a double dose effect.

That makes sense. I haven\'t personally gotten a white egg, but someone I sold a bird to last year got some that she *thinks* is from a wheaten I sold her, but she\'s not positive. She doesn\'t breed and bought it as a layer only, so it\'s really not an issue, but now it\'s on my radar and I\'m keeping an eye out for any more.

[Mike Gilbert]

This is kind of off on a tangent, but if you read the abstract found at the link in my previous post, there is good evidence
that blue egg chickens did not originate in South America.  The study involves a blue egg chicken native to China, and there is good evidence Polynesians brought chickens to South America eons ago.   I have always maintained that all the chickens we have are descended from the seven that came off Noah\'s ark about 4,000 or so years ago.   One other point;  the O gene produces blue egg shell, but the o gene does not produce white egg shell, it simply designates a gene that is neutral with regard to shell color.  Other, unrelated genes produce white and/or brown shells.

[John]

but the o gene does not produce white egg shell, it simply designates a gene that is neutral with regard to shell color.

\"O\" adds blue to the shell and \"o\" just means blue isn\'t added.
But in the absence of any genes to add brown to the shell a bird that is o/o will lay white eggs.  It seems to me that since a bird that is o/o produces white eggs you could say that o produces white egg shells.
Just as Mb adds, produces or causes muffs and mb doesn\'t.  We generally would still say mb/mb produces a clean faced bird, just because Mb wasn\'t there to produce muffs.
Am I missing something?

[John]

If I were to start over again

I would do some things differently also, but for the most part I think it was done right.  
Looking at LF only...
Silvers and wheatens had the best egg color for years, but still lack type and size compared to the other varieties.  They also still have white showing up in their earlobes.  Silvers are the least docile.  I would drop both varieties to free up breeding coops, but want to see them improved so I keep breeding them.
Brown reds lack size and their egg color isn\'t great, but they have the proper type and you are making progress with color/pattern.
Blacks are #1 in the showrooms and Paul and others have made huge improvements in their egg color (as good as any) and eye color.  They have arrived, so to speak.
Buffs are getting better each year.  Egg color and combs are the two biggest problems.  They are the most docile and will always be my favorites.
Lavenders are lacking in size a bit and egg color will be improved over the years, but they have great type, eye color, combs, etc.  Their black cousins are to thank.  The lavender color may never be perfect, but I like it.
Boy, if only we knew then what we\'ve learned over the decades.  I know some of the other old timers on this forum, like Wayne and Jerry would agree.
And look at all the new blood out there running the club, breeding and exhibiting.  It can only get better!

[Tailfeathers]

I just happened to be cleaning out the coop last Saturday when one of my #7 BW pullets was sitting in a nest.  I have 3 pullets that are laying a white egg now.  She is one of them.  

My #7 parents are #12 Wheaten roo & #10 BW hens.  These two #10 BW hens laid an almost white egg and a white egg. I was able to determine that the white egg was coming from the original #13 chicks that I bought.   I bred them because of productivity problems I was experiencing and they give me about 4-5 eggs each per week.  So I knew the #10 line would likely give me lighter eggs.

My #12 Wheaten roo was the result of #14 BW roo over #15 BW hen.  

In 2009 I determined that my #15 BW Cockerel & #15 BW Hen both thru pullets that laid white eggs in 2010.  I guess I missed that when I bred him last year.  

Now I\'m really going to have to check things over because I think I\'ve got some pretty good looking #7\'s out there with lots of color in the tail and wings and at least some of them must be laying a blue egg.  I can definitely cull my #10 BW hens this year and that will take care of part of the problem.  Now I just have to decide if I want to not breed any birds that had #12 as their Daddy.  

I think I\'m gonna have to sit down and make a family tree of the different lines.  That may be the only way I can figure this out.  Or maybe I\'ll just continue to work on the type, size, comb size, beard color and leg color and not worry so much about the egg color for now.  I\'ve gotten rid of the red from the tails, the beards are almost fully colored on my young males now which is a significant improvement.  I\'m getting nice red earlobes (culled everything that had pale lobes).  And egg size and productivity seems to be doing real well.  

So whattaya\'ll think?  Any suggestons?

God Bless,

[Mike Gilbert]

Royce, if it is possible you might want to consider penning each suspect separately for a while.  That is the way to find out what color egg they are each laying.   Even show cages work for me when the birds are laying.

[Tailfeathers]

Oh, Mike I\'ll be separating out all the birds to see who is laying what.  Most certainly.  I have to do that as the last step in deciding who I want to finally breed.  I\'ve got a few birds that are laying the best blue egg I\'ve ever had.  Really, really good deep blue.  Better than \"sky blue\".  It\'ll be just my luck that the birds who lay those eggs will also have something wrong with them that I wouldn\'t otherwise want to breed.

The question I had about \"any suggestions\" was more along the lines of what to do with the lineage I laid out.  In particular, what do I do with my #7\'s where, if things turn out like I expect, I will have some of them laying nice blue eggs and have good color in the tails and wings?  Do I breed them knowing they may still be throwing some recessive white egg genes?  And what about the #7\'s that are laying white eggs?  If they are really good elsewise, should I breed them and worry about getting the blue back later?  

I tend to lean toward \"Yes\" to both questions but would like to hear from others.  Of course I\'ll keep my other lines going too and see how they turn out.  Maybe one of these days I\'ll be down to just two W lines and two BW lines.

Btw, here\'s a monkey to throw in the mix... I have a #7 BW Cockerel that has almost completely clean hackles!  My first.  He\'s also got good type, good color, and a really good, small, tight comb.  Eye and Leg color could be a bit better but overall I think he may turn out to be my best BW male.  But he\'s a #7!!!

God Bless,

[Mike Gilbert]

By all means breed the #7 BW rooster.   If he is that good, I would even save a white egg layer to test mate him with.
If all his pullet offspring from that cross lay blue eggs, then you will know he is a winner for sure.   By the way, you are much better off with white eggs than brown eggs; count your blessings!