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Author Topic: Genetics of egg color  (Read 1522 times)

Lindsay Helton

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Genetics of egg color
« on: February 08, 2017, 04:18:39 PM »
Can someone explain the genetics behind egg color to me? I have been focusing on type the last three seasons, while of course only setting blue eggs, but this year I would like to focus in on egg color more closely. I have marked the eggs that are the deepest shade of blue, and plan to mark those chicks for identification later on.

Is egg color influenced by the cock, hen, or both? I read somewhere online that it is influenced by around 13 genes...I don't know if that is true or not. If anyone has any reading material that they can recommend, I would be appreciative.

Each year I hatch and keep several hundred chicks. Unfortunately, this season a wheaten pullet that hatched from a blue egg grew up to lay a pink egg. My bloodline originated from one of the directors, and they are definitely true Ameraucanas. The other pullets that I kept from that pen lay blue eggs. Do I need to consider culling the cock from that pen?  I raise for show and he has great type, so I would prefer not to. However, I do want to be sure that I keep egg color in mind. It is definitely a balancing act. Most of my pens are set up with one cock over five hens, so I can't say for certain what hen she came from. I would like to get my pen sizes smaller, say one cock to three hens, but that will involve building more pens, and I am trying to give my husband a little break from coop and pen building. LOL!
« Last Edit: February 17, 2017, 12:40:37 AM by Lindsay Helton »
-Lindsay

"If you continuously compete with others, you become bitter, but if you continuously compete with yourself, you become better."

Susan Mouw

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Re: Genetics of egg color
« Reply #1 on: February 08, 2017, 05:44:36 PM »
I posted a link to an article about this some time ago.  I'll see if I can find it and repost it.
Susan Mouw
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Susan Mouw

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Re: Genetics of egg color
« Reply #2 on: February 08, 2017, 07:10:02 PM »
Susan Mouw
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Lindsay Helton

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Re: Genetics of egg color
« Reply #3 on: February 09, 2017, 12:16:14 AM »
Thank you Susan!!!

I am trying to be sure I understand completely. I used B to denote egg color.

I gathered from the article that egg color is simple dominant.

Since one of the pullets grew up to lay pink eggs, the cock would have to be carrying a recessive allele for non blue eggs (I'll name him Bb), as well as one of the hens in that pen (I'll name her Bb as well) thus creating the pink egg layer, right? I do not know definitively regarding what color egg the cock was hatched from, since he wasn't hatched here, although I'm sure it was from a blue egg because I know the breeder well.

The hens that were in that particular pen have been culled (due to age). But regardless, that would still mean that the cock is not completely dominant for blue eggs right? So he would be Bb instead of BB?

So how does an off colored egg layer happen from a pullet that hatched from a blue egg?

Is it because the offspring only receive one allele from each parent? So in the case of a Bb cock mating with a Bb hen (a hen that lays blue eggs but carries the recessive allele), there would be a 25% chance that the chicks inherit the recessive trait for non blue eggs (bb)?

Sorry if I am making this more difficult than it is. :) I am not well versed in genetics. Lol
« Last Edit: February 09, 2017, 12:19:40 AM by Lindsay Helton »
-Lindsay

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Susan Mouw

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Re: Genetics of egg color
« Reply #4 on: February 09, 2017, 08:48:30 AM »
You have it exactly right.  If this is a single gene recessive trait, as put forth by Punnett, then both the hen and the cock are carrying at least one copy of that recessive, in order for any chicks to have both copies and show the recessive trait.

So, yes..the cock was Bb and the hen was Bb.  So you have a 25% chance of BB (pure for blue eggs), 50% chance of Bb (mixed for blue eggs. Eggs will all show blue, but can pass on the trait for non-blue to offspring), and 25% chance of bb (pure for non-blue) in the chicks.
Susan Mouw
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Lindsay Helton

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Re: Genetics of egg color
« Reply #5 on: February 09, 2017, 01:48:04 PM »
Thank you for the feedback! Maybe before its all said and done, I'll have this genetics thing understood. Lol! Would you guys cull the cock from that pen, regardless of his type? I am breeding for show first and foremost, but I do want to keep egg color in mind along the way.
-Lindsay

"If you continuously compete with others, you become bitter, but if you continuously compete with yourself, you become better."

Don

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Re: Genetics of egg color
« Reply #6 on: February 09, 2017, 04:20:46 PM »
Lindsay,  As you've read there are a number of genes involved that correlate to blue color and the brown overlay of the eggs.  We don't know how these are triggered or how they may be related.  So it's only safe to assume that both male and female contribute to each of the genes.  It is frustrating when your pullets start laying off colored eggs for sure.  And many new people are ready to call anything that does not produce perfect blue eggs something other than pure AM.  Could be that one of your hens last year was carrying something that triggered a gene or two to activate.  It would not be the first time a female was carrying something that she did not express herself.  You did say that you only had one pullet laying an off color.  But you did not mention how many pullets are laying a good colored egg?  Do you think that most of the hens were OO and only one hen was Oo, therefore you only had one hen that was oo?  From my limited understanding, would this not provide a white egg?  JMO, but this might not answer the pink egg problem.  Especially if you have nice eggs from your other offspring.  I wonder, Could pink come from some brown egg coloring?  I don't have any good solid answers for this.     

You said your male came from a blue egg and some of his offspring is producing good colored eggs.  So if your male is really that great, it might be worth test mating him this season to see if he really is the carrier.  Mark the youngsters well and see how they produce.  I would think that if he is the problem you will have more off colored eggs.  If not then you may have saved a good brood stock.   
« Last Edit: February 09, 2017, 04:44:05 PM by Don »
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Lindsay Helton

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Re: Genetics of egg color
« Reply #7 on: February 09, 2017, 06:37:41 PM »
Hi Don,

Thanks for your response. I'm guessing that apparently only one of the hens was carrying the recessive trait that led to the pinkish egg, or there would be more of them. I tried to attach a photo of the egg color that I'm seeing from the other pullets, but it said the file size is too large. When I'm on a computer instead of my phone, I'll reduce the file size and submit it. I need to buy one of those handy egg color charts so that I can just say the number. :) I'll do that this week.  They range from faint sky blue to baby blue in color, with fairly good saturation of color overall. I agree with you, I think the pinkish color relates to the brown egg gene. I have heard of some self blues laying pinkish colored eggs.

Thanks for the help. Several people have encouraged me to keep the cock since he has good type. I think I'll keep him around and see what he produces this year. The hens that were in his pen last season were culled, and he has a new set of hens this year. I'll probably reduce the size of his breeding pen and mark all the chicks that hatch from his pen to monitor them closely for egg color. I have two other pens that I can work with during the mean time.
« Last Edit: February 11, 2017, 07:01:34 PM by Lindsay Helton »
-Lindsay

"If you continuously compete with others, you become bitter, but if you continuously compete with yourself, you become better."

Paul

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Re: Genetics of egg color
« Reply #8 on: February 26, 2017, 09:21:17 AM »
  Egg color is influenced by many modifier genes-the Punnett square is useless with egg color!  If egg color was only dominate and recessive-the good blue egg would be the only eggs laid by now-with as many generations as there has been since their creation.

  Our original start of wheaten/blue wheaten came from Wayne Meredith, on September 25, 1999.  Every breeder added was also a descendant of Wayne's.  Wayne is credited for the creation of the large fowl wheatens.  He used an oversize bantam cockerel from Mike Gilbert, on his large fowl EEL flock that mostly resembled the wheatens.  Most of the good wheatens in the US can trace their roots to Wayne's flock.

  We raised the wheatens for several years before a pink egg was ever laid!  Occasionally one will surface from a pullet.  She is sold as a layer for eggs to be eaten ASAP.  We have never set a pink egg and don't recommend setting any of them.

  I recommend departing with the pink egg layer pullet, and keeping all the other birds as breeders that are in the breeding program.

 
Paul Smith

Lindsay Helton

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Re: Genetics of egg color
« Reply #9 on: February 28, 2017, 10:56:05 PM »
  Egg color is influenced by many modifier genes-the Punnett square is useless with egg color!  If egg color was only dominate and recessive-the good blue egg would be the only eggs laid by now-with as many generations as there has been since their creation.

  Our original start of wheaten/blue wheaten came from Wayne Meredith, on September 25, 1999.  Every breeder added was also a descendant of Wayne's.  Wayne is credited for the creation of the large fowl wheatens.  He used an oversize bantam cockerel from Mike Gilbert, on his large fowl EEL flock that mostly resembled the wheatens.  Most of the good wheatens in the US can trace their roots to Wayne's flock.

  We raised the wheatens for several years before a pink egg was ever laid!  Occasionally one will surface from a pullet.  She is sold as a layer for eggs to be eaten ASAP.  We have never set a pink egg and don't recommend setting any of them.

  I recommend departing with the pink egg layer pullet, and keeping all the other birds as breeders that are in the breeding program.

 

Thank you for your response Paul! I appreciate it. That puts my mind at ease.

I didn't want to cull the cock from that pen, because he has produced a blue wheaten pullet that received reserve champion LF at a show, Champion AOSB at another show, and he also produced a blue wheaten hen that received reserve of breed at the Dixie Classic against a fairly good size class of Ameraucanas. I kept a lot more hens this year and am setting enough eggs now that I can start focusing in more on egg color. I continue to look at type first and foremost. A special thank you to all of those that lend an ear when I have breeding questions.

« Last Edit: February 28, 2017, 10:58:06 PM by Lindsay Helton »
-Lindsay

"If you continuously compete with others, you become bitter, but if you continuously compete with yourself, you become better."