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#34543 - 01/19/10 10:49 AM Egg shell colors (genetics)
Anonymous
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I was referred to this forum by a person in a another chicken forum where they couldn't answer my questions. I'm hoping someone here can explain what is going on with some eggs I'm getting.

I've read many times that there are two base shell colors - white and blue. I've also read that it's pigment overlaid on this base that give various shades of greens and browns. Now to my question.

The following are eggs from a line of ameraucanas I have (white egg for comparison). I had them for 3 generations and these are the first eggs that were not blue. Some are greenish, some are pinkish. In the past, they were all like the egg on the far left.






Notice, the pinkish egg has the same color on the inside of the shell as the outside. Careful examination also shows the color to go throughout the full thickness of the shell. It cannot be scraped off with a knife. The green shell is the same way. The color on the inside is not the same as the color of the blue shell next to it. It's greenish like the outside of the shell.

Can someone explain why the shell is pink inside if it's a white shell?

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#34544 - 01/19/10 11:22 AM Re: Egg shell colors (genetics)
Henk69 Offline
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I can't see what you mean.
You think that if it is a brown tinted eggshell, it should be white inside?
And in case of a green (blue + brown) eggshell it should be blue inside?

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#34545 - 01/19/10 11:26 AM Re: Egg shell colors (genetics)
Anonymous
Unregistered


Yes, I have read that brown eggs are simply white shells with brown pigment on the outer layer. Is this incorrect?

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#34546 - 01/19/10 01:24 PM Re: Egg shell colors (genetics)
Blackdotte Offline
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Registered: 10/02/04
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Loc: Australia
Blue eggs have a blue coloured shell, as a result of the O gene, and can be O/O or O/o+. The various shades of green to khaki are caused by an overlay of brown pigments. The intensity of blue can vary. A dark blue layer line mated to a pure white layer line, such as Leghorns, will usually result in a paler blue egg. The base shell colour for a brown egg is white; the final shade, cream to red-brown being a result of the amount of brown pigment laid down.

Croad Langshans, one of the parent breeds of Marans, laid a plum egg.



I find many of my Marans lay an egg that has a plum shell, the plum colouring going right through the shell, in the way of the blue shell. I know of no genetic studies on the plum egg shell. However, the base colour of the Marans' eggs, white or plum, does not affect the final colour due to laid down pigments.
David

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#34547 - 01/19/10 01:26 PM Re: Egg shell colors (genetics)
Rhea Dean Carter Offline
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Registered: 07/24/03
Posts: 1379
Loc: Tennessee
Steve, that is the information I have read, too. If you have a hen that is laying pink-tinted eggs with the color going all the way through the shell, then I would make certain I knew which one was laying such eggs. I think you have something rare that you need to try and preserve.

By the way, what variety of Ameraucanas do you have (black, blue, white, buff, etc.)?
_________________________
Rhea Dean

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#34548 - 01/19/10 01:55 PM Re: Egg shell colors (genetics)
Anonymous
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Originally Posted By: blackdotte
The base shell colour for a brown egg is white; the final shade, cream to red-brown being a result of the amount of brown pigment laid down.
So are you saying the brown pigment is not laid on the surface but is mixed through the full thickness of the shell?

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#34549 - 01/19/10 02:01 PM Re: Egg shell colors (genetics)
Anonymous
Unregistered


Originally Posted By: Rhea Dean Carter
Steve, that is the information I have read, too. If you have a hen that is laying pink-tinted eggs with the color going all the way through the shell, then I would make certain I knew which one was laying such eggs. I think you have something rare that you need to try and preserve.

By the way, what variety of Ameraucanas do you have (black, blue, white, buff, etc.)?
They are blue, black, and splash; and there are three hens laying the pinkish egg, which brings me to another question. From what I've read, blue shell and pea comb are linked. Can a cockerel carry the gene for single comb and have a pea comb?

Below is a photo of the cockerel in this mating. I'm not sure if the comb is clear enough to evaluate, but since I had him over for dinner not too long ago, I can't get anymore photos of him. The hens all seem to have very nice pea combs.


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#34550 - 01/19/10 02:55 PM Re: Egg shell colors (genetics)
IPF Offline
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Yes, he can be heterozygous and carry one pea (P) and one non-pea (p) gene. Sinc P is dominant, he will be genotype Pp and have a pea comb. (In reality, the dominance is often partial, so that a heterozygote may have a comb that is somewhat intermediate for pea comb.)
He can pass on either gene to his offspring.

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#34551 - 01/19/10 03:13 PM Re: Egg shell colors (genetics)
Blackdotte Offline
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Registered: 10/02/04
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Loc: Australia
Originally Posted By: Steve
So are you saying the brown pigment is not laid on the surface but is mixed through the full thickness of the shell?
No. What I said was the final colour was due to pigments laid down on the surface of the shell.
David

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#34552 - 01/19/10 03:18 PM Re: Egg shell colors (genetics)
Anonymous
Unregistered


Originally Posted By: blackdotte
No. What I said was the final colour was due to pigments laid down on the surface of the shell. David
If the pigment is laid on the surface, why are these eggs the same color on the inside as the outside?

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#34553 - 01/19/10 04:02 PM Re: Egg shell colors (genetics)
Anonymous
Unregistered


Originally Posted By: ipf
Yes, he can be heterozygous and carry one pea (P) and one non-pea (p) gene. Sinc P is dominant, he will be genotype Pp and have a pea comb. (In reality, the dominance is often partial, so that a heterozygote may have a comb that is somewhat intermediate for pea comb.) He can pass on either gene to his offspring.
I have made such a cross several times, and the resulting birds all have very poor pea combs--almost intermediate between pea and single comb. Combs in this line producing the pink eggs have been very consistent with no pinkish eggs in at least the past several generations (including prior owner's generations). I never even had a green egg from prior generations.

It makes me suspect that there is a recessive gene or two that mask the expression of the blue egg on a bird homozygous for P.

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#34554 - 01/19/10 04:17 PM Re: Egg shell colors (genetics)
IPF Offline
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I don't understand what you're saying; please elaborate.

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#34555 - 01/19/10 05:16 PM Re: Egg shell colors (genetics)
Anonymous
Unregistered


If the shell color is pinkish (brown) all the way through, why do they say shells only come in blue and white?

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#34556 - 01/19/10 06:07 PM Re: Egg shell colors (genetics)
Blackdotte Offline
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Steve, please read my original post again. I have said there are also plum eggs that have colour all the way through the shell. I have also stated that I have not seen any researched documentation in respect to this. Note plum is also variable in shade, and your pink could well be in this spectrum. I did not say there were only blue and white shells.
David

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#34557 - 01/19/10 06:35 PM Re: Egg shell colors (genetics)
IPF Offline
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Loc: Canada
Thanks, David. I also have seen no good documentation of brown/pink colour through the shell but have seen it in my own hens' eggs and wondered. A curious omission in the literature - is it the chook equivalent of the emperor's new clothes, or maybe we're not looking in the right places?

Steve, I'm still curious about your statement: "It makes me suspect that there is a recessive gene or two that mask the expression of the blue egg on a bird homozygous for P."

I assume you're using P in the conventional sense, i.e. the allele for pea comb? Or are you perhaps using it for "pink?" In either case, I don't understand your meaning.

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#34558 - 01/19/10 06:43 PM Re: Egg shell colors (genetics)
IPF Offline
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Registered: 04/08/08
Posts: 466
Loc: Canada
Also, check out this Coop thread.
No solid answers, but at least assures us that someone else is wondering about the same thing.
http://www.the-coop.org/wwwboard/discus/messages/15/5817.html

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#34559 - 01/19/10 06:50 PM Re: Egg shell colors (genetics)
IPF Offline
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The Nagoya breed seems to lay pink eggs.

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#34560 - 01/20/10 02:47 AM Re: Egg shell colors (genetics)
Henk69 Offline
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Steve,

Do you mean that all heterozygous peacombed (and thus also het blueshell) animals of your flock lay pink eggs instead of the expected blue eggs?
So an incomplete dominant blue eggshell mutation instead of the documented complete dominant blue eggshell.

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#34561 - 01/20/10 05:13 AM Re: Egg shell colors (genetics)
Anonymous
Unregistered


Originally Posted By: Henk69
Do you mean that all heterozygous peacombed (and thus also het blueshell) animals of your flock lay pink eggs instead of the expected blue eggs?
So an incomplete dominant blue eggshell mutation instead of the documented complete dominant blue eggshell.
I'm relatively new to chicken genetics, so what I know about the different gene interactions is very limited. From what I understand, pea comb and blue shell are linked. Blue is dominant over white, and pea comb is dominant (co-dominant) over single comb. Since the previous 5-6 generations produced only blue eggs, it seems a good chance these birds are homozygous for blue, which means they should also be homozygous for pea comb. The combs seem to also verify this. There is little variation in comb type.

For such birds to lay a pink egg would require another gene(s) that would mask the expression of blue. Simple crossovers accounting for these pink eggs would occur much less frequently than what I've observed in my birds.

Regardless of whether I've got the gene interaction correct or not, the basic thing I'd like to establish is that pink eggs are not a white egg with brown pigment on the surface--at least not the ones I have. Mine are pink on the outside, in the middle, and on the inside. There seems to be nothing in any literature I've read that addresses this. It refers to white shells, blue shells, and the effect brown pigments have on these two shell colors.

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#34562 - 01/20/10 09:46 AM Re: Egg shell colors (genetics)
Bushman Offline
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Registered: 07/25/07
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Loc: Wisconsin
Originally Posted By: Steve
From what I understand, pea comb and blue shell are linked. Blue is dominant over white, and pea comb is dominant (co-dominant) over single comb. Since the previous 5-6 generations produced only blue eggs, it seems a good chance these birds are homozygous for blue, which means they should also be homozygous for pea comb.

For such birds to lay a pink egg would require another gene(s) that would mask the expression of blue. Simple crossovers accounting for these pink eggs would occur much less frequently than what I've observed in my birds.

Regardless of whether I've got the gene interaction correct or not, the basic thing I'd like to establish is that pink eggs are not a white egg with brown pigment on the surface-- at least not the ones I have. Mine are pink on the outside, in the middle, and on the inside.
Steve, yes, P and O are closely linked, but that does not mean your birds have to be homozygous for both. There are single comb birds that lay blue eggs without fail from generation to generation. My opinion is that a few of your breeders have been hetero for the O (blue eggshell) gene, and you are just now finding that out. Also, I'm not sure if all the genes for brown shell have been studied and documented. Last report I heard there have been about a dozen identified, with some being dominant, some recessive. Perhaps there is a gene yet to be discovered that results in brown pigment being distributed throughout the shell, and I think that is what you are asking. I don't think anybody knows.
_________________________
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#34563 - 01/20/10 02:00 PM Re: Egg shell colors (genetics)
Anonymous
Unregistered


Originally Posted By: Bushman
Perhaps there is a gene yet to be discovered that results in brown pigment being distributed throughout the shell, and I think that is what you are asking. I don't think anybody knows.
Yes, that is what I'm asking. I think my photos demonstrate that the pigment goes through the whole shell. I thought that many would have seen something similar. I'm finding out that some have, but most haven't.

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#88424 - 03/02/10 05:54 PM Re: Egg shell colors (genetics) [Re: ]
Wieslaw Offline
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While I can't directly answer to your question, I want to mention that mutations of pigment from blue to pink are very common in the realm of plants. There are many genera when normally blue flowers, in case of mutation nearly always turn to pink (gentiana, campanula, tradescantia, forget-me-not). Why couldn't it happen to eggshells?

As far as the O gene is concerned, to say that it only gives blue colour (in absence of brown pigments) is an over simplification in my opinion. I have some crosses between Araucana and Leghorn. While definitely pale blue on the outside, the shells are definitely pale green INSIDE (tested on four persons). So if the inside colour is the "real" representation of the gene, so it can be either blue OR green.

I have also seen an egg that was very intense gray (not dirty blue). It can't be explained with brown pigments.

On this link you can read about almost unbelievable colours. I wonder if anybody has seen a vivid orange egg.

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#88773 - 03/30/10 02:40 PM Re: Egg shell colors (genetics) [Re: Wieslaw]
Wieslaw Offline
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Blackdotte, could you please make a picture of the inside of the shells of your plum coloured eggs?

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#88776 - 03/30/10 03:37 PM Re: Egg shell colors (genetics) [Re: Wieslaw]
Blackdotte2 Offline
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Loc: Australia
Don't get many but will look out for one.
David

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#89069 - 04/23/10 03:55 PM Re: Egg shell colors (genetics) [Re: ]
Wieslaw Offline
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My old bantam, which is the only hen of mine that lays tinted eggs, started laying again. I boiled her egg today, pulled the membrane of, and to my amazement the inside of her shell was NOT white. It was lighter than the outside, but there was a definite difference compared to the white Leghorn egg. I have always been reading that brown eggs are supposed to be white inside. Now I'm not sure what to think.

1. The shell is so thin that I can see the colour through the shell.
2. Some brown eggs are white inside, some are not.
3. We all have been living one "BIG LIE."

So now, those of you who breed Rhode Island Reds, Langshan, Marans, etc., would you boil an egg and tell me if they are white inside or not?

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#89071 - 04/23/10 03:58 PM Re: Egg shell colors (genetics) [Re: Wieslaw]
RuffEnuff Offline
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I will have boiled egg for dinner tonight and see.

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#89091 - 04/25/10 02:27 AM Re: Egg shell colors (genetics) [Re: RuffEnuff]
RuffEnuff Offline
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Sorry, I had avaocado last night as they were all ripening so fast, but tonight after a late lunch (more avocado) I had three soft boiled eggs for dinner. Now when eating a soft boiled egg I notice you do leave behind the white membrane of the shell still attached to the egg shell. I did peel back the white membrane and did find the shell underside was STILL white. The egg was from my very average brown egg laying Marans pullet. It was a nice brown on the outside, not super brown/red.

If you want to look at this site where there is a lively discussion on brown eggs, I have an egg photo there that I have used sandpaper to remove the brown layer. I also have photos where I show where the brown layer has been removed because it has stuck while it was still wet (upon being laid), and the sticky brown coating became stuck to the nesting material. When the nesting material was removed, it took the brown coating with it.

Discussion

However, I see this point being made as very important, and I am going to remove the white inner membrane and photograph the egg for this above topic.

Thank you, wieslaw. Please go to the above link to the topic as I am sure it should satisfy you of your concerns.

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#89621 - 06/05/10 06:30 AM Re: Egg shell colors (genetics) [Re: Anonymous]
Wieslaw Offline
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Originally Posted By: Wieslaw
I have also seen an egg that was very intense gray (not dirty blue). It can't be explained with brown pigments.

I have just experienced that one of my green layers laid an egg like this. The gray just washed off (or it looked like it did) under the running water, so the egg was normally green again. But after the egg dried, it looks gray again. WHAT IS THIS?


This is the egg in the middle. I made it wet to show you the colour(It is actually much more green in reality)


Edited by Wieslaw (06/05/10 04:41 PM)
Edit Reason: added picture

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#109868 - 06/16/13 12:59 AM Re: Egg shell colors (genetics) [Re: Wieslaw]
Alaskan Offline
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Registered: 06/16/13
Posts: 1
Loc: Alaska, USA
What? This thread stops here?

Don't stop! Continue discussing egg color!

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#109869 - 06/16/13 03:49 AM Re: Egg shell colors (genetics) [Re: Alaskan]
Foehn Offline
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Wieslaw, I have had the odd dark brown (Barnevelder) egg look like this, with a whitish bloom on it. Also goes dark brown if wet. I think it is caused by being delayed in the laying process. Usually it does not concern the whole egg. It has always been an egg that would normally have been laid around the 23-26 hour mark, but for some reason they have gone to more like 36 hours since the last egg was laid.

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#109870 - 06/16/13 06:04 AM Re: Egg shell colors (genetics) [Re: Foehn]
Bushman Offline
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If memory serves I believe there have been identified about a dozen different brown shell genes, and undoubtably some of those are non allelic, so a single hen can be affected by multiple brown pigmented shell genetics. It stands to reason some of them would affect only the surface of the egg while others may permeate the entire shell. And then some would be recessive and others dominant. In the long run it is what it is. I can't see investing large amounts of time and money to get to the bottom of it all, as so many other factors are higher on my priority list visually, aesthetically, and economically.
_________________________
Pilgrim in a foreign land and true believer.
1st John 5:11-12

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#109876 - 06/17/13 03:17 AM Re: Egg shell colors (genetics) [Re: Bushman]
Norwegian Offline
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I think this white layer is something that has been bred into some types of white-egglayers.
I have it in some of the hens in my breeding project, most likely from crosses with Australorps, Orustchickens or Icelandic landrace chickens. frown
It affects all hues of bluegreen as well as dark brown eggs.
Here it has nothing to do with delay and affects the whole egg - just a thin transparent wash. I also get the occasional egg with white only on part of the egg. Then it is coarser and more "chalky".


Edited by Norwegian (06/17/13 04:12 AM)

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#109877 - 06/17/13 03:30 AM Re: Egg shell colors (genetics) [Re: Norwegian]
Jocelyn Offline
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You can breed out that white coating, it's an "either or" type thingy. You get a coating or no coating, but not a thinner coating. Re the greyish eggs when blue/green, I think it's structure, rather than a coating. They reflect the light differently when wet, but dry back to their original look of greyish surface. When I get breakfast, I'll cook some eggs and post again.

jocelyn

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#109894 - 06/18/13 05:28 AM Re: Egg shell colors (genetics) [Re: Jocelyn]
Jocelyn Offline
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Well, nothing real definative after breakfast. here is a group of shells. The hatched shell is a commercial brown egg, note the white inner surface. The green eggs are modern game mated to araucanas, and the light brown is a serama.



Uploaded with ImageShack.us

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#110253 - 08/02/13 10:00 PM Re: Egg shell colors (genetics) [Re: Jocelyn]
Smooth Mule Offline
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This is Not a normal color egg for my hens but nonetheless, it was laid by one of my black Araucana hens and not in the nest box but in the outside pen.

I sure hope there is another laid of this color but none yet

[img]http://www.backyardchickens.com/t/288425/lightbox/post/11687617/id/5876687[/img]

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#110270 - 08/04/13 08:14 AM Re: Egg shell colors (genetics) [Re: Smooth Mule]
Wieslaw Offline
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Smooth Mule: WOW!

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#110902 - 11/03/13 08:33 PM Re: Egg shell colors (genetics) [Re: Wieslaw]
Smooth Mule Offline
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I still get an occasional egg like the one I posted. I hope this thread continues as requested earlier. It's very interesting to those of us who breed for a particular color egg.

At this point, I'm beginning to take egg color more seriously since my Araucana's type, feather color, skin color etc are coming along so well. I have a bit of a wide range in egg color at this point, from very pale blue to a good blue and a couple of not yet identified hens that lay green tinted eggs so I will be working on correcting that.

I do have a question, that for some reason I can't seem to figure out with a punnet square. If you don't know what color your cock hatched from and you didn't hatch him so you can't really know what genes his parents gave him. One of my friends has hens laying good blue eggs. From her cock (not raised by her) to those hens, of 4 pullets she kept, 3 lay good blue eggs and one lays green eggs. So, if the hens lay blue, can they carry a brown egg gene or not? Is it safe to assume then, that it's the cock that carries a brown egg gene to produce a pullet that lays a greenish egg? Or, can the hens lay blue eggs but still carry a brown egg gene?

I offered her this idea, she is hatching chicks now. She should set only blue eggs and tag the cockerels that came from blue eggs to keep for possible replacements to the sire, breed those cockerels to blue egg layer hens and do the same. If a cockerel is hatched from a blue egg by a cock that likely carries at least a single brown egg gene, could he still carry a brown egg gene?

What would be a better way to breed out the brown egg gene? and can the hens carry a brown egg gene but lay blue?
What would be a good way to test breed a cockerel to see if he carries a brown egg gene, and since her cock did produce 3 of 4 pullets that lay blue, he would be het for brown egg gene then?
Thanks
Cathy

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#110904 - 11/04/13 01:53 AM Re: Egg shell colors (genetics) [Re: Smooth Mule]
Norwegian Offline
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The gene for blue eggs is dominant, so a hen with just one gene would lay a blue or green egg. But it is my opinion, from experience, that you need two genes to get really good blue eggs.

But like it is stated somewhere above here, the brown egg genes are not one, but several genes. I think it is important to set only the very best eggs. And if possible to have control of which hens lay greenish eggs and replace those too.
A good eggcolour is as important in Araucanas as other traits. ;-)

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#110907 - 11/05/13 06:00 PM Re: Egg shell colors (genetics) [Re: Norwegian]
Smooth Mule Offline
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Thanks. Good advice

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#111019 - 11/22/13 06:24 PM Re: Egg shell colors (genetics) [Re: Smooth Mule]
Wieslaw Offline
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I have found something interesting

http://www.learningace.com/doc/4683872/3fec39714557b022bf39558a936b1a35/p0683-p0692

Quote:

Kennedy and Vevers (1973) also did a chromatographic analysis of the egg-shell pigments of the Araucano fowl, finding that these egg shells contained protoporphyrin, biliverdin IXc• and its zinc chelate, and traces of coproporphyrin I. These eggs vary in color, especially through various shades or tints of blue and green. The absorption spectra of different fractions showed the basic color differences: deep pink for the fraction identified as protoporphyrin, deep greenish-blue for the biliverdin IXc• fraction, and bright emerald-green for the pigment chemically identified as the zinc chelate of biliverdin IXc•.

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#111022 - 11/23/13 05:01 AM Re: Egg shell colors (genetics) [Re: Wieslaw]
Norwegian Offline
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Registered: 08/31/03
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Interesting!!

Was a bit difficult reading the document in the setting in your link. Is there any way I can save it or print it? blush

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#111023 - 11/23/13 06:39 AM Re: Egg shell colors (genetics) [Re: Norwegian]
Wieslaw Offline
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There is an I-icon at the top to select text. Then you can just copy it as you usually do.

Anybody else remembers an old thread on how to make blue eggs bluer? Somebody suggested adding zinc to the diet. According to the piece I quoted, if anything, it would perhaps make the eggs greener not bluer.

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#111024 - 11/23/13 06:23 PM Re: Egg shell colors (genetics) [Re: Wieslaw]
KazJaps Offline
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Registered: 08/30/02
Posts: 2864
Loc: Australia
Yes, there is a belief by some (eg by "Kermit", etc) that copper & zinc added to the diet would benefit blue eggshell colour (part of the theory - Sth America soils higher in copper, etc, Araucanas originated from Sth America.....).

The Coop: Very interesting article on the process of eggshell formation in poultry
http://www.the-coop.org/forums/ubbthreads.php?ubb=showflat&Number=33187#Post33187

The Coop: IF diet affects egg color, which ingredients help?
http://www.the-coop.org/forums/ubbthreads.php?ubb=showflat&Number=32052#Post32052

Don't know if it has ever been tested scientifically?
-----------------------
The following from
An EAV-HP Insertion in 5' Flanking Region of SLCO1B3 Causes Blue Eggshell in the Chicken
Wang et al.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3554524/pdf/pgen.1003183.pdf

Quote:
SLCO1B3 codes a membrane transporter OATP1B3 which is considered a liver-specific transporter and is highly expressed in liver where it transports a wide range of substrates including bile salts [24], [25]. A genome-wide association study (GWAS) for serum bilirubin levels also showed SLCO1B3 is a plausible candidate gene responsible for changes in bilirubin levels in humans [26]. As blue egg is colored mainly by deposition of biliverdin on the eggshell and biliverdin is just one component of the bile salts, the expression of the SLCO1B3 in uterus could enhance transportation of biliverdin to eggshell. In this study, we found that SLCO1B3 is exclusively expressed in shell gland of uterus of blue-shelled chickens rather than in that of brown- or white-shelled chickens, which supports that the gene plays a pivotal role for coloration of blue eggs.


So the SLCO1B3 gene influences biliverdin, & the O mutation modified expression of SLCO1B3 in the shell gland/uterus of blue egg laying chickens.

-----------------------
Jocelyn posted an interesting study on the effects of carotenoids on blue & green eggshell colour (by influencing Biliverdin, an important component for blue eggshell pigment).

Biliverdin-based egg coloration is enhanced by carotenoid supplementation.
Judith Morales, Alberto Velando and Roxana Torres
Behavioral Ecology and Sociobiology, 2011, Volume 65, Number 2, Pages 197-203
http://webs.uvigo.es/avelando/pdfs_archivos/moralesetal2011BESa.pdf

The study was on blue-footed boobies (these lay blue-green eggs).

Quote:
The color of first eggs (laid prior to manipulation) did not differ between experimental treatments.....

Under natural conditions, second eggs were paler than first ones, suggesting pigment limitation throughout laying (Fig. 1). However, the color decline in the laying sequence disappeared with carotenoid treatment, second eggs of carotenoid-supplemented females being more colorful than control second eggs.


So supplementation with carotenoids helped to alleviate the problem of reduction of blue pigment over the laying cycle. Ie, the carotenoids didn't increase blue pigment with the first egg, but helped keep the same colour, no fading with the 2nd egg.


Edited by KazJaps (11/23/13 06:42 PM)
Edit Reason: fixed ′ = "apostrophe" code error

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#111026 - 11/24/13 08:04 AM Re: Egg shell colors (genetics) [Re: Wieslaw]
Norwegian Offline
Coop Keeper

Registered: 08/31/03
Posts: 523
Loc: Norway

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#111028 - 11/24/13 05:43 PM Re: Egg shell colors (genetics) [Re: Wieslaw]
Smooth Mule Offline
Coop Keeper

Registered: 02/13/10
Posts: 659
Loc: Missouri
Very interesting, thank you! Shared with my other Araucana friends

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#111041 - 11/26/13 06:06 AM Re: Egg shell colors (genetics) [Re: Wieslaw]
Piet Offline
Flock Leader

Registered: 10/07/10
Posts: 262
Loc: Belgium
Originally Posted By: Wieslaw
to make blue eggs bluer? Somebody suggested adding zinc to the diet. According to the piece I quoted, if anything, it would perhaps make the eggs greener not bluer.[/b][/color]


This could work either way.If adding Zinc would increase the green colour...selection against it could be easier/stricter?...

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#111053 - 11/30/13 01:48 PM Re: Egg shell colors (genetics) [Re: Piet]
Wieslaw Offline
Moderator
Classroom Professor

Registered: 09/18/09
Posts: 3840
Loc: Denmark
[quote=Piet
This could work either way.If adding Zinc would increase the green colour...selection against it could be easier/stricter?... [/quote]

Perhaps, it is a matter of trying it out.

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#114704 - 08/19/15 06:49 PM Re: Egg shell colors (genetics) [Re: Wieslaw]
Redcap Offline
Ruler of the Roost

Registered: 08/14/06
Posts: 985
Loc: Germany
Originally Posted By: Wieslaw
I have found something interesting

http://www.learningace.com/doc/4683872/3fec39714557b022bf39558a936b1a35/p0683-p0692

Quote:

Kennedy and Vevers (1973) also did a chromatographic analysis of the egg-shell pigments of the Araucano fowl, finding that these egg shells contained protoporphyrin, biliverdin IXc• and its zinc chelate, and traces of coproporphyrin I. These eggs vary in color, especially through various shades or tints of blue and green. The absorption spectra of different fractions showed the basic color differences: deep pink for the fraction identified as protoporphyrin, deep greenish-blue for the biliverdin IXc• fraction, and bright emerald-green for the pigment chemically identified as the zinc chelate of biliverdin IXc•.


Here is the study as PDF

ELSIE C. COLLIAS (1993). INHERITANCE OF EGG-COLOR POLYMORPHISM IN THE VILLAGE WEAVER (PLOCEUS CUCULLATUS). The Auk 110(4):683-692 + frontispiece
https://sora.unm.edu/sites/default/files/journals/auk/v110n04/p0683-p0692.pdf

A few days ago I found some interesting studies

H. Lukanov, A. Genchev, A. Pavlov (2015). COLOUR TRAITS OF CHICKEN EGGS WITH DIFFERENT EGGSHELL PIGMENTATION. Trakia Journal of Sciences,Vol. 13, No. 2, pp. 149-158.
http://www.researchgate.net/publication/...ll_Pigmentation

Quote:
A small group of West European breeds created by the end of 19th and the early 20th century are outlined with excessive protoporphyrin pigmentation resulting in dark brown shell colour – these are the Marans, Welsumer and Barnevelder breeds. In Germany and the UK, egg - laying hybrids laying dark brown eggs were created on the basis of Marans. There are also populations, lines and individuals producing eggs with violet, saturated blue colour, with rose tint of the eggshell etc.. In some breeds (Marans, Bielefelder) and strains, eggshells are speckled,which is manifested with appearance of dark spots of various shape and size at the background (mainly brown).


Samiullah S., Roberts J. R. (2013). The location of protoporphyrin in the eggshell of brown-shelled eggs. Poult. Sci.;92:2783-2788.
http://ps.oxfordjournals.org/content/92/10/2783.abstract

Samiullah S, Roberts JR, Chousalkar K (2015). Eggshell color in brown-egg laying hens - a review. Poult Sci. 2015 Aug 3. pii: pev202. 1-10
http://ps.oxfordjournals.org/content/early/2015/08/03/ps.pev202.full.pdf

J.L. Campo and María Teresa Prieto (2010). Fluctuating asymmetry in hens laying brown eggs with shell color abnormalities or internal inclusions Schwankende Asymmetrie bei braunschalige Eier mit Farbabweichungen oder Eieinschlüssen legenden Hennen. Arch.Geflügelk., 74 (2). S. 126–132
http://www.european-poultry-science.com/...D6FB4699B76B2DC

Sun C, Qu L, Yi G, Yuan J, Duan Z, Shen M, Qu L, Xu G, Wang K, Yang N (2015). Genome-wide association study revealed a promising region and candidate genes for eggshell quality in an F2 resource population. BMC Genomics. 2015 Jul 31;16:565.
http://www.biomedcentral.com/content/pdf/s12864-015-1795-7.pdf

Odabasi A. Z., Miles R. D., Balaban M. O., Portier K. M. (2007). Changes in brown eggshell colour as the hen ages. Poult. Sci. 2007;86:356-363.
http://ps.oxfordjournals.org/content/86/2/356.full.pdf

Aurélien Brionne, Yves Nys, Christelle Hennequet-Antier and Joël Gautron (2014). Hen uterine gene expression profiling during eggshell formation reveals putative proteins involved in the supply of minerals or in the shell mineralization process. BMC Genomics 2014, 15:220.
http://www.biomedcentral.com/content/pdf/1471-2164-15-220.pdf

Jesús M. Avilés, Juan J. Soler, Nathan S. Hart (2011). Sexual selection based on egg colour: physiological models and egg discrimination experiments in a cavity-nesting bird. Behavioral Ecology and Sociobiology, Volume 65, Issue 9, pp 1721-1730
http://www.eeza.csic.es/Documentos/Publicaciones/Avil%C3%A9s,%20Soler,%20Hart%202011%20pg.pdf

Daphne C Fecheyr-Lippens, Branislav Igic, Liliana D'Alba, Daniel Hanley, Aida Verdes, Mande Holford, Geoffrey I N Waterhouse, Tomas Grim, Mark E Hauber, Matthew D Shawkey (2015). The cuticle modulates ultraviolet reflectance of avian eggshells. Biol Open 2015 11;4(7):753-9. Epub 2015 May 11.
http://bio.biologists.org/content/4/7/753

Daniel B Thomas, Mark E Hauber, Daniel Hanley, Geoffrey I N Waterhouse, Sara Fraser, Keith C Gordon (2015). Analysing avian eggshell pigments with Raman spectroscopy. J Exp Biol jeb.124917; First posted online June 25, 2015.
http://jeb.biologists.org/content/early/2015/06/24/jeb.124917.abstract

Cassey P, Portugal SJ, Maurer G, Ewen JG, Boulton RL, Hauber ME, et al. (2010). Variability in Avian Eggshell Colour: A Comparative Study of Museum Eggshells. PLoS ONE 5(8): e12054.
http://www.plosone.org/article/fetchObje...resentation=PDF

CASSEY, P., THOMAS, G. H., PORTUGAL, S. J., MAURER, G., HAUBER, M. E., GRIM, T., LOVELL, P. G. and MIKŠÍK, I. (2012). Why are birds' eggs colourful? Eggshell pigments co-vary with life-history and nesting ecology among British breeding non-passerine birds. Biological Journal of the Linnean Society, 106: 657–672.
http://onlinelibrary.wiley.com/doi/10.1111/j.1095-8312.2012.01877.x/abstract

Hanley D, Grim T, Cassey P, Hauber ME. (2015). Not so colourful after all: eggshell pigments constrain avian eggshell colour space. Biol. Lett. 11: 20150087.
http://www.zoologie.upol.cz/osoby/Grim/Hanley_et_al_Biol_Lett_2015.pdf



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#114708 - 08/20/15 04:18 PM Re: Egg shell colors (genetics) [Re: Redcap]
KazJaps Offline
Classroom Professor

Registered: 08/30/02
Posts: 2864
Loc: Australia
Discoloration of Egg Shells from Feeding High Levels of Certain Tetracyclines
D. J. Bray and S. F. Ridlen
Poultry Science (1967) 46 (1): 258-259 doi:10.3382/ps.0460258
http://ps.oxfordjournals.org/content/46/1/258.full.pdf

*Extremely high levels of Chlortetracycline in the diet caused hens to produce greenish-yellow eggs.

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#114710 - 08/21/15 01:00 AM Re: Egg shell colors (genetics) [Re: KazJaps]
Redcap Offline
Ruler of the Roost

Registered: 08/14/06
Posts: 985
Loc: Germany
One another publication about Marans, a kind of status report about the Marans breed and varieties - in french.
Riga, Paul (2009). Bilan diagnostique des élevages de poules de race Marans en Poitou-Charentes et Vendée.

http://www.cregene.org/IMG/pdf/bilan_stage_poule_Marans_2009.pdf
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#114715 - 08/22/15 12:11 AM Re: Egg shell colors (genetics) [Re: KazJaps]
Redcap Offline
Ruler of the Roost

Registered: 08/14/06
Posts: 985
Loc: Germany
Originally Posted By: KazJaps
Yes, there is a belief by some (eg by "Kermit", etc) that copper & zinc added to the diet would benefit blue eggshell colour (part of the theory - Sth America soils higher in copper, etc, Araucanas originated from Sth America.....).

The Coop: Very interesting article on the process of eggshell formation in poultry
http://www.the-coop.org/forums/ubbthreads.php?ubb=showflat&Number=33187#Post33187

The Coop: IF diet affects egg color, which ingredients help?
http://www.the-coop.org/forums/ubbthreads.php?ubb=showflat&Number=32052#Post32052

Don't know if it has ever been tested scientifically?
-----------------------
The following from
An EAV-HP Insertion in 5' Flanking Region of SLCO1B3 Causes Blue Eggshell in the Chicken
Wang et al.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3554524/pdf/pgen.1003183.pdf

Quote:
SLCO1B3 codes a membrane transporter OATP1B3 which is considered a liver-specific transporter and is highly expressed in liver where it transports a wide range of substrates including bile salts [24], [25]. A genome-wide association study (GWAS) for serum bilirubin levels also showed SLCO1B3 is a plausible candidate gene responsible for changes in bilirubin levels in humans [26]. As blue egg is colored mainly by deposition of biliverdin on the eggshell and biliverdin is just one component of the bile salts, the expression of the SLCO1B3 in uterus could enhance transportation of biliverdin to eggshell. In this study, we found that SLCO1B3 is exclusively expressed in shell gland of uterus of blue-shelled chickens rather than in that of brown- or white-shelled chickens, which supports that the gene plays a pivotal role for coloration of blue eggs.


So the SLCO1B3 gene influences biliverdin, & the O mutation modified expression of SLCO1B3 in the shell gland/uterus of blue egg laying chickens.

-----------------------
Jocelyn posted an interesting study on the effects of carotenoids on blue & green eggshell colour (by influencing Biliverdin, an important component for blue eggshell pigment).

Biliverdin-based egg coloration is enhanced by carotenoid supplementation.
Judith Morales, Alberto Velando and Roxana Torres
Behavioral Ecology and Sociobiology, 2011, Volume 65, Number 2, Pages 197-203
http://webs.uvigo.es/avelando/pdfs_archivos/moralesetal2011BESa.pdf

The study was on blue-footed boobies (these lay blue-green eggs).

Quote:
The color of first eggs (laid prior to manipulation) did not differ between experimental treatments.....

Under natural conditions, second eggs were paler than first ones, suggesting pigment limitation throughout laying (Fig. 1). However, the color decline in the laying sequence disappeared with carotenoid treatment, second eggs of carotenoid-supplemented females being more colorful than control second eggs.


So supplementation with carotenoids helped to alleviate the problem of reduction of blue pigment over the laying cycle. Ie, the carotenoids didn't increase blue pigment with the first egg, but helped keep the same colour, no fading with the 2nd egg.


This study shows contradictory results

James L. Stahl, M.E. Cook, J.L. Greger (1988). Zinc, iron, and copper contents of eggs from hens fed varying levels of zinc. Journal of Food Composition and Analysis.Volume 1, Issue 4, November 1988, Pages 309–315

http://www.sciencedirect.com/science/article/pii/0889157588900300

Quote:
Ingestion of excess zinc did not have consistent effects on the iron or copper content of eggs or on the zinc content of eggshells.


So there is still the question, how green egg colour could be modulated by feeding of supplements.
It is known, that enzymes reduce brown pigmentation, so there should be a feed based effect for brown or green eggs.
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#115696 - 04/24/16 06:54 AM Re: Egg shell colors (genetics) [Re: Bushman]
Redcap Offline
Ruler of the Roost

Registered: 08/14/06
Posts: 985
Loc: Germany
Is the green egg color only linked to the maternal-line in cuckoos?
http://www.bioquicknews.com/node/3246
In Great Tits there is an maternal link to Speckles as well
http://www.backyardchickens.com/t/129430...0#post_12966836
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#115698 - 04/24/16 08:13 AM Re: Egg shell colors (genetics) [Re: Redcap]
Redcap Offline
Ruler of the Roost

Registered: 08/14/06
Posts: 985
Loc: Germany
http://www.nature.com/ncomms/2016/160112/ncomms10272/full/ncomms10272.html

Frode Fossøy, Michael D. Sorenson, Wei Liang, Torbjørn Ekrem, Arne Moksnes, Anders P. Møller, Jarkko Rutila, Eivin Røskaft, Fugo Takasu, Canchao Yang and Bård G. Stokke (2016). Ancient origin and maternal inheritance of blue cuckoo eggs. Nature Communications 7, Article number: 10272.
Very interesting is reference to this study.
Quote:
The plausibility of selection generating adaptation through changes in one or more W-linked genes is strengthened by a recent study showing that increased female-specific selection in chickens during domestication has resulted in increased expression of W-linked genes 18
http://www.pnas.org/content/109/21/8207.full.pdf
Moghadam, H.K., Pointer, M.A., Wright, A.E., Berlin, S., & Mank, J.E. (2012). W chromosome gene expression responds to female-specific selection. Proceedings of the National Academy of Sciences, USA, 109: 8207–8211
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#115701 - 04/29/16 12:29 AM Re: Egg shell colors (genetics) [Re: Redcap]
Redcap Offline
Ruler of the Roost

Registered: 08/14/06
Posts: 985
Loc: Germany
I remember, that I read somewhere in a scientific publication, that the E (black) variety lay in general darker eggs, than the less melanizised varieties (e.g. eWh)
This goes conform with the experience of Marans breeder. Over-melanized hens lay darker eggs.
http://maranschickenclubusa.com/SMF/index.php?topic=936.0
Does anyone know a scientific reference which confirm this observation?
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#115702 - 04/29/16 04:52 PM Re: Egg shell colors (genetics) [Re: Redcap]
KazJaps Offline
Classroom Professor

Registered: 08/30/02
Posts: 2864
Loc: Australia
You could look up duck eggshell colour genetics, see what the current research says.

Sellers' website:
http://kippenjungle.nl/sellers/page6.html

Duck Genetics: Extended Black
Quote:
Typical of the Black Orpington, Black Cayuga and Black East Indian. Evidence exists suggesting that extended black influences eggshell color giving it a grey tint.


Although with the Chinese research on chicken blue eggshell genetics, they say that the duck blue eggshell phenotype is not caused by the same mutation as in chickens. The trait is dominant though.

Plus in Mallard wild-type ducks their eggs can be greenish (colour varies), so this needs to be kept in mind.


Edited by KazJaps (04/29/16 04:53 PM)

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#115706 - 05/02/16 10:54 AM Re: Egg shell colors (genetics) [Re: KazJaps]
Redcap Offline
Ruler of the Roost

Registered: 08/14/06
Posts: 985
Loc: Germany
By accident I came over the questioned paper ...
Originally Posted By: Redcap
P. MÉRAT, A. BORDAS, G. Coquerelle, L. Durand. GÈNES A EFFET VISIBLE ET COLORATION OU ÉPAISSEUR DES COQUILLES D'OEUFS. Annales de génétique et de sélection animale, 1970, 2 (3), pp.263-267. <hal-00892399>
HAL Id: hal-00892399
https://hal.archives-ouvertes.fr/hal-00892399
Quote:
SUMMARY
GENES WITH VISIBLE EFFECT AND THICKNESS
OR EXTERNAL PIGMENTATION OF EGGSHELLS
Among 12 loci studied in one population, two, concerned
with plumage color, show an association with thickness and external
pigmentation of eggshells : Pullets with extended black compared with
restricted black plumage (E locus) and pullets with colored (ii) vs non-black
plumage (Ii) lay eggs with significantly thicker and more intensely pigmented
shells. A similar but less marked tendency seems to be associated, for shell thickness, with two other plumage color loci (C and S).


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