True or False? Olive egg genetics.

[The Kooky Kiwi]

@DarJones - Do you have any further wisdom to add re: speckled?

@Allsfairinloveandbugs asked about speckled and I'll confess I'm also interested to see how that works

 

[Kiki]

 

[Allsfairinloveandbugs]

@The Kooky Kiwi , Thank you again! I believe you explained why i was able to retain the blue egg genes in my flock despite a lot of outcrossing. Except for the easter egger/welsummer roo i mentioned, have Mostly only ever kept easter egger roos hatched from blue eggs with the easter egger hens. Also, chose Many blue eggs to hatch. (I understood i could never be certain the roos carried double blue egg color genes). Since am now getting a few white egg layers from the easter egger parents, understand thats likely coming from the blue andalusians, introduced to get blue-Feathered easter eggers. (Darn on the white eggs though). I do think many of the original easter egger flock members had double blue egg genes. (Early in this thread i became confused if this was even possible).

Also, when i first started crossing those slate-shanked easter egger roos with yellow-shanked hens, discovered another sex-linked trait. All the next generation pullets had blue shanks, while all the boys had yellow shanks. I was very surprised, & researched to verify that yes that is a real thing!

One question in your example crossing a Blue/Blue hen and a "white egg" rooster carrying -/-. You said that mom contributes one blue egg gene to 100% of the chicks, & dad contributes one blue egg gene to 50% of the chicks, & one - (white?) egg gene to 50% of the chicks. I guess i'm clueless again. Cause i would have thought that cross would result in all chicks carrying Blue/-.

Its late, and i cant comprehend anymore info tonight. But i WILL revisit this thread this weekend, & keep trying to absorb all the information being communicated here. Have learned a lot already!

 

[Allsfairinloveandbugs]

@DarJones , im not gonna be able to comprehend your latest post tonight. But i will Definitely read it this weekend asap. And, will probably have more questions to ask you too. Thank you for your input also; it has been very helpful.

 

[The Kooky Kiwi]

One question in your example crossing a Blue/Blue hen and a "white egg" rooster carrying -/-. You said that mom contributes one blue egg gene to 100% of the chicks, & dad contributes one blue egg gene to 50% of the chicks, & one - (white?) egg gene to 50% of the chicks. I guess i'm clueless again. Cause i would have thought that cross would result in all chicks carrying Blue/-.

WOOPS! Oh you are so right! Sorry yes I'm also tired and miswrote that - So I've now amended my original post to avoid confusing any future readers

You are right yes - Blue/Blue mom with -/- roo = ALL babies are Blue/- (Blue egg layers)

 

[Allsfairinloveandbugs]

Thats ok i only know enough to be dangerous.

 

[DarJones]

I saw the statement re blue/blue hens and a white egg rooster and decided to let someone else point it out. Glad to see OP saw it!

Anything I say regarding speckled eggs will just be spec...ulation.

I have seen eggs with small extra pimples of calcium deposited on top of porphyrin in some instances. I have seen small dots of extra dark porphyrin on some eggs. From this, I would guess that some chickens carry a trait where small clumps of cells in the egg tube preferentially either produce calcium slightly out of sequence or produce additional porphyrin on small spots. This is bound to be genetic. If you save eggs from chickens that express this trait, you should be able to increase the frequency and eventually stabilize a line with heavily spotted and speckled eggs. I really don't know any more than this as the chickens I am working with have been heavily selected away from these traits.

 

[The Kooky Kiwi]

Anything I say regarding speckled eggs will just be spec...ulation.

 

[nicalandia]

Cross of Brown X Blue is not going to give precisely the same result as crossing Blue X Brown. Reciprocal crosses are affected by the W/Z chromosomes as some of the genes in the porphyrin biopath are on the sex chromosomes.

That said, you can still generalize that crossing a blue egg layer X a brown egg layer and carrying forward to the F2, 1 in 16 will lay white eggs, 3 in 16 will lay some shade of brown egg, 1 in 16 will lay some form of blue egg (caused by recombination of the blue and white genes where the white gene disables the porphyrin biopath), and 11 in 16 will lay some form of egg carrying the blue egg gene with varying overlay of porphyrin producing olive green, teal, spearmint green, tan green, or other slightly nuanced color on top of the blue egg shell.

I agree that reciprocal crosses will affect the shade of green on the F1 because there is at least two mutations affecting brown pigment expression on the shell(inhibitor and enhancer), but I dont agree that 1/16th of the F2s will lay blue eggs(homozygous or Heterozygous for Oocyan and a complete lack of brown pigment genes), we are dealing with more than a dozen genes here.

 

[DarJones]

we are dealing with more than a dozen genes here.

How about you set up a breeding flock of brown X blue layers and hatch out 320 F2 chicks (160 females) then count how many lay blue eggs. This should conclusively demonstrate how many genes are involved in turning off porphyrin production. I'll even suggest which breeds would work really well. Get some Whiting Blue hens and use a good brown egg laying breed like Wyandottes for roosters.

I'll even up the ante. I've already hatched @300 chicks from my birds in 2021. I'll be hatching out about 200 more before stopping for the season. I'll track the number of blue egg layers and see how the ratio stacks up.

This is not intended to be confrontational. I am simply stating that the way to answer the question in the real world is easy to set up.