Is egg color genetics really male driven?

[NatJ]

For example, F1 should lay all green eggs due to the cross
F2 could lay any color but who knows what color the cockerals "lay" so they are your mystery element, if you cull all hens that lay different color eggs, then breed them back to your green layer rooster, then all of their kids in the F3 generation SHOULD have just the green egg genes because you know their mothers only have green genes (they lay green eggs) and you know their father is also a green egger due to his breed.

After that F3 generation you should be able to breed them between themselves and back to the green eggers from the starting generation to get the traits you need as long as you don't outcross again to another color of egg layer the green eggs should be more or less fixed in your "breed" you are starting.

Um, that doesn't quite work.

F2 hens that lay green eggs could have OO (pure for blue egg gene) or Oo (split for blue egg gene.) So some will breed true for the blue egg gene, but some are just as mixed as the F1 hens were.

Crossing those F2 hens back to OO rooster (pure for blue egg gene) will give some that are pure for the blue egg gene, but some could still produce Oo chicks (impure for blue egg gene.)

You could test individual F2 chickens, of either gender, to see whether they are pure for the blue egg gene, although it's a nuisance because it takes a lot of time & space. Cross each one to a bird that is pure for not-blue, hatch a bunch of chicks, raise pullets to laying age, and see if any lay not-blue eggs. If you have get at least half a dozen daughters, and all of them lay blue or green, then it's a fair guess that their one parent was pure for the blue egg gene. (At which point you can use the parent in your breeding program, but you may have no use for all those pullets that were produced as part of the test--you know they have at least one not-blue gene because that was required to make the test work.)

 

[Kusanar]

Um, that doesn't quite work.

F2 hens that lay green eggs could have OO (pure for blue egg gene) or Oo (split for blue egg gene.) So some will breed true for the blue egg gene, but some are just as mixed as the F1 hens were.

Crossing those F2 hens back to OO rooster (pure for blue egg gene) will give some that are pure for the blue egg gene, but some could still produce Oo chicks (impure for blue egg gene.)

You could test individual F2 chickens, of either gender, to see whether they are pure for the blue egg gene, although it's a nuisance because it takes a lot of time & space. Cross each one to a bird that is pure for not-blue, hatch a bunch of chicks, raise pullets to laying age, and see if any lay not-blue eggs. If you have get at least half a dozen daughters, and all of them lay blue or green, then it's a fair guess that their one parent was pure for the blue egg gene. (At which point you can use the parent in your breeding program, but you may have no use for all those pullets that were produced as part of the test--you know they have at least one not-blue gene because that was required to make the test work.)

Thanks for the elaboration. I'm not super up to speed on chicken egg laying genetics so wasn't aware that they could be split and still show the blue egg. Good to know.

 

[NatJ]

Thanks for the elaboration. I'm not super up to speed on chicken egg laying genetics so wasn't aware that they could be split and still show the blue egg. Good to know.

Yes, the blue egg gene is dominant. That's why people can cross a blue layer (Cream Legbar or Ameraucana) with a dark brown layer (Marans) to get olive eggs (blue + dark brown.)

Or why the F1 will all lay green eggs.

 

[Cycomiko]

Thanks for the elaboration @Kusanar and @NatJ. I hadn't thought about the egg color past F1 before starting this thread. This goes a long way, and my homeschooled son should have a good project to document. He's 13 now, so he can see some generations on this project.

 

[Kusanar]

Thanks for the elaboration @Kusanar and @NatJ. I hadn't thought about the egg color past F1 before starting this thread. This goes a long way, and my homeschooled son should have a good project to document. He's 13 now, so he can see some generations on this project.

Keep us posted on the results!

 

[Cycomiko]

The hatch didn't go so well. 9 eggs set, 1 somehow broke, 7 didn't hatch but did evolve, and one hatched on a 19f degree day. The one that did hatch, was a Svart roo x Silverudd hen, and it did not completely fibro. crown and legs and start of feet are black, but doesn't extend. It was a horrible hatch time, as it caused another girl to go broody, and rather than give her eggs, I elected to give her fake eggs and chicks the other would hatch, but this was it. So I sent Mamma #1 to brooding hospital with the chick, and started over with the one that was only broody for a week and a half. I gave here all green eggs, 3 Svart roo x Silverudd eggs and 2 full breed Silverudds. Immediately after, I put 19 Swedish Flowers eggs, 2 Swedish Flower roo x Cream Legbar eggs (curiosity), 1 Silverudd, 2 Svart roo x Silverudd hen, and 13 Silverudd roo x Svart Hona eggs in the incubator. If getting off in extreme cold kills the next ones babies, I'll have immediate backups. What made this a problem, 2 more Svarts keep going mini broody, and the others have been mad at the nesting boxes they want being taken, it totally slowed production of this coop. Oh well, spring will be here soon enough.

 

[theoldchick]

https://microbewiki.kenyon.edu/index.php/Genetics_of_Egg_Color_in_Chickens

 

[Willawong Hill]

Hopefully you get a better hatch next time. Keep us updated!

 

[Cycomiko]

Hopefully you get a better hatch next time. Keep us updated!

Will do! I have 2 more setting on eggs, and many in the incubator to give out babies to if it's another botch. I can't believe we've had 6 Svarts go Broody since late October, and 5 since early December. And we are getting pounded with snow!

 

[DarJones]

The genes you are working with are brown egg, blue egg, and white egg.

In your breeds, the only blue is the South American variant of oocyanin. It is a dominant gene meaning that any hen with one copy of the gene will lay a blue tinted egg.

I was able to identify 3 separate genes that produce white eggs. The most desirable is the intense white as found in leghorns. The other two genes produce a washed out version of white egg shell. This does not mean that there are only three genes involved, it just means that I was able to pick out results showing at least 3 are out there in different breeds. It is important to understand that all chicken eggs start out white and are either tinted blue by the oocyanin gene or are coated brown by porphyrin.

Brown eggs are a whole nother ball of wax. There is an entire biopath dedicated to coating eggs with porphyrin. All chickens have the porphyrin biopath, but in breeds that lay white eggs, it is interrupted at one or more places to turn off the brown coating. A study of the literature showed at least 7 different genes in the porphyrin biopath with mutations in at least 3 producing white eggs. A chromosome translocation with a lot of undesirable side effects is one variation that produces white eggs. If you are crossing a green egg layer with a white egg layer, you will wind up with segregation for some brown egg layers, some white egg layers, some sky blue egg layers, and some olive egg layers. The ratios I got were 8 brown, 1 white, 1 sky blue, and 6 olive. The number of chickens I raised was not high enough to confirm this as a verifiable and repeatable result so use this with caution.

IMO, after about 4 or 5 generations of selecting for oocyanin, it would be a really good idea to dna test for the blue egg gene and try to identify a couple of homozygous roosters. Why? If a rooster with two copies of the blue egg gene mates with a random group of hens that all lay blue eggs, the next generation should all lay blue/green eggs and about 5/8 should be homozygous for the oocyanin gene.

Also worth knowing, if you combine a white egg gene with a blue egg gene, the result is sky blue eggs. In other words, with the porphyrin biopath disabled, the eggs will not be coated and will not appear greenish/brown.