What can cause loss of egg color in pure Ameraucanas?

[Guest]

Would it be a recessive gene that might cause the blue to be lost after 4 or 5 years of breeding only blue eggs?

Or is the most obvious reason that somewhere before that, there was a cross?

[John]

Would it be a recessive gene

Probably.  Blue egg shell color is dominant to white, so if a hen and cock in your flock both carry at least one gene for white egg shell color they could produce offspring that are pure for it.
I\'ve had the same thing happen with a couple bantam wheatens (one last year and one this year) that lay tinted white to light brown eggs after about 20+ years or breeding from only blueish eggs.
 

[Mike Gilbert]

The only way to be sure your birds are homozygous for blue egg gene is to test mate them with brown or white egg laying chickens.   It\'s a long process, because you have to raise the test pullets up to egg laying age.    Best to furnish a disclaimer when making sales, but I think most knowledgeable buyers are aware of the potential problem.
The hatcheries get away with it by claiming some of their chickens might lay \"pink\" or other colored eggs.

[Blue Egg Acres]

Is it necessary to cull tinted white/light brown layers to eliminate the problem? or can one cross them with a cockerel that is out of a blue egg from another line  and get birds that produce blue eggs?

[Guest]

Would it be a recessive gene

Probably.  Blue egg shell color is dominant to white, so if a hen and cock in your flock both carry at least one gene for white egg shell color they could produce offspring that are pure for it.
I\'ve had the same thing happen with a couple bantam wheatens (one last year and one this year) that lay tinted white to light brown eggs after about 20+ years or breeding from only blueish eggs.
 

That is probably what happened, the rooster was used on his daughers concentrating the genes.

So,  there shouldn\'t be a problem breeding pullets from that rooster who do lay a blue egg  to an unrelated rooster?

[Mike Gilbert]

Depends on your objective.   Do you just want a generation that lays bluish eggs, or do you want a pure line?  They are two different things.   If the latter, the only way to be sure is to do what I said in my previous post.

[grisaboy]

That is probably what happened, the rooster was used on his daughers concentrating the genes.
So,  there shouldn\'t be a problem breeding pullets from that rooster who do lay a blue egg  to an unrelated rooster?

You have to assume that all of the pullets from that rooster carry the recessive gene for non-blue eggs.  It might not show up in the next generation but it will eventually.
You would have to test mate them to a non-blue egg breed to be sure which ones are pure for blue eggs.  Only about one third of the blue egg laying pullets from that rooster would be pure for blue eggs.
If they are the best in your flock, you can still keep them.  Mark them with a white legband or something so you can tell who they are.  Breed them back to their father and you can probably find out which ones are carrying the non-blue egg genes.  Any that hatch all blue egg layers are probably pure.  You have to continue the process for the next generations too since those pullets also could be spilt.
As soon as you have enough females that have proven to be pure for blue eggs, you should get rid of all of the ones that carry the non-blue egg genes.

Curtis

[John]

Is it necessary to cull tinted white/light brown layers to eliminate the problem? or can one cross them with a cockerel that is out of a blue egg from another line and get birds that produce blue eggs?

Yes and yes, but the second option shouldn\'t be considered if you implement the first one.
Cull any that lay eggs without a hint of blue.
I\'ve seen some blue eggs that almost look white.  The strains that produced them may carry white (o), so the eggs may not be as blue as the ones from a hen carrying two copies of the blue (O) egg gene.  If the strain produces some true white, tinted white or brown eggs from time to time it would be a good time for an outcross with another strain.
Even though Ameraucanas should lay blue eggs the standard and more importantly the ABC has never defined what shade of blue a blue egg should be.  We know it shouldn\'t be green, but for many they desire a shade that is darker than a pure blue (O/O) egg without brown modifiers.  The blue eggs that are most appealing to the eye and photograph well have a bit of tint or very light brown surface coating that blends with the blue to make the normally very light pastel blue egg look closer to the Robin\'s egg blue some dream of.

[Blue Egg Acres]

Ok, so. . . what can we expect out of the males that are sibling to the brown/white egg laying pullets all of which are from the blue eggs?

[Mike Gilbert]

Barb, there is no way to know without test mating.   He could have inherited the O gene from both parents (homozygous), from one of them (heterozygous), or from neither.    Anything other than homozygous can lead to brown or white eggs down the road.

[grisaboy]

Ok, so. . . what can we expect out of the males that are sibling to the brown/white egg laying pullets all of which are from the blue eggs?

If  OO is pure for blue eggs
    oo is pure for non-blue eggs
   Oo is split.
Obviously with the males you can\'t tell which are carrying non-blue egg genes like you can with the pullets. But the percentages will be the same. 25% OO; 50% Oo; 25% oo.
The only way to determine which ones carry the non-blue egg genes is to test mate to a non-blue egg laying female.  If any non-blue egg laying females are produced, then the male is a carrier.  
It might be best to assume all of these males are carriers and only keep them if they are very superior for other traits.

Curtis

[John]

Barbara,

I\'ve known you for years and know you have bred some great birds, so please don\'t think this is a really big deal.  It is just one more of many traits that have to be worked on and improved.  Remember the black in the hackle, lacing in the breast and all the other things that come to our attention over the years?  This is just one more to add to the list.  They are a work in progress, like every other breed and variety.
As Curtis and Mike said test mating is the only way to truly find out if a bird is pure are blue (OO) eggs, but I don\'t know of anyone that plans to do it.  
Just as you can generally tell by looking at a bird\'s muffs if they are pure for muffs and only breed from those that appear to be you can try to do the same with egg color.  If you have some pullets that end up laying actual white eggs then some of your birds are not pure for blue eggs.  In that case I would suggest not breeding from any birds that come from those extremely light blue eggs...assuming those are the birds that are not pure.  

[Blue Egg Acres]

Thanks guys. Your advice is, as always, much appreciated!

[Tailfeathers]

Very interesting comments!  Thought I\'d throw my two-cents into the mix.

Over the years, I have kept detailed records on my various birds.  Each bird is toe-punched at birth according to the Pen # from which it came.  Each pen consists of a specific male over a female (or females if they are full-blooded sisters).  

In doing so I have been able to backtrack the results of some traits.  One of those has been the elimination of brown in most of my eggs.  I am now only getting a greenish tinted egg from one pullet - I think.  However, this year I have two pullets giving me a totally white egg.  But, on the other hand, I have a few pullets that I think are giving me a bluer egg than I\'ve ever had.

I think (as I have not caught the culprit on the nest yet) that the two white egg layers are probably from my #10 hens.  I had two #10 hens, one of which gave me a white egg, and the other an almost white with very light blue hue to it.  

I bred them though to my rooster that I think is carrying my best blue egg genes and I did so because I was having terrible productivity problems.  I had 6-8 birds that hadn\'t given me an egg in over 6 months.  My #10\'s would give me 4-5 eggs each per week.  So my thought was, \"I\'ll get the productivity up and then weed out the white gene in subsequent generations.\"  

This may be obvious but my point is that I can rarely afford to focus on just one trait.  It always seems to be a matter of priorities for me.  My hope is that with time and continued good record keeping, thru the process of elimination and repeating successes while not repeating mistakes, I can get to where I want to be.

Lastly, I thought I\'d mention something - again that may go without saying but will perhaps be of benefit to someone - with regard to the test mating.  Mike\'s idea of test mating is an excellent idea.  But just remember that if you do it, you\'ve got to hatch a whole lot of birds so that if the recessive gene is there, it will show up in the percentages.  

At least if I understand the process that is correct.  If I have a rooster carrying Oo and mate it to a hen that is oo, then I still have a 75% chance of blue eggs.  Right?  So I would have to hatch a lot of chicks to get the pullet that lays the white egg in order for me to know that I\'ve got a rooster with the recessive white.  If I only hatch a handful of chicks, I might not get the white egg and would mistakenly assume that I had a rooster that was OO.

God Bless,

[Mike Gilbert]

- with regard to the test mating.  Mike\'s idea of test mating is an excellent idea.  But just remember that if you do it, you\'ve got to hatch a whole lot of birds so that if the recessive gene is there, it will show up in the percentages.  

At least if I understand the process that is correct.  If I have a rooster carrying Oo and mate it to a hen that is oo, then I still have a 75% chance of blue eggs.  Right?

Nope.  Royce, blue eggshell is a single gene dominant trait.  Birds that are Oo mated to oo should yield about half that lay blue or green eggs and half that do not.   It should come out about 50/50.  The real problem with the test mating is that you end up with all these pullets that are useless in where you are trying to go with your breeding program.   It helps if there is a market for backyard layers in your area.   The roosters from the test matings could either be raised for fryers or culled as soon as their sex is determinable.