Chicken Egg Color Genetics Discussion

[Brahma Chicken5000]

Legbars have white lobes and lay blue eggs.
I don't believe lobe color is linked to egg color at all.
Legbars also have single comb so not sure how pea combs are supposed to be linked to blue eggs either.

I’ve heard that about the pea comb as well. Let’s say that a rooster carrying the blue egg gene and a pea comb was used to bring the blue egg gene into the Legbar. The resulting offspring of the blue egg carrying sire and Legbar dam would be heterozygous for the pea comb (P,p) and if the cockerels were test mated and were found to carry the blue egg gene they could then be crossed back to a Legbar hen and the resulting offspring would be 50% heterozygous for the pea comb (P,p) and the other 50% would be homozygous for single combs (p,p) and then if the single comb cockerels were test mated and found to carry the blue egg gene they could then be backcrossed to a Legbar hen and all of the offspring would carry the blue egg gene and be homozygous recessive for the pea comb (p,p) which would result in all offspring having single combs.

 

[ChickenCanoe]

I was told there is a feed you can get to change the color of the eggs, Is this true

Not for shell color.
That said, the pigments are organic compounds that require several chemicals to be present in the system in order for the hen to be able to apply them to the shell. Chemicals present in the body for all sorts of functions ultimately come from food. So deficiencies can possibly cause hues to be more pale and adequate quantities could make the hue darker because more pigment was available.
When an egg is formed, the pullet that hatches from that egg has all the genetics to dictate what pigments/colors are going to be applied to the shell of her eggs. Food can't change those genes and the resultant egg color.

Feed with marigold in it will make the egg yolk a darker yellow but it will not effect the shell color

Chickens don't assimilate carotenoids and when consumed, they end up in the egg yolk affecting color. Marigold - or any feedstuff that contains carotenoids in sufficient quantity will enhance yolk color. That can be sweet potatoes, tomatoes, squash, dark leafy greens, carrots, even yellow corn.

 

[ChickenCanoe]

Here is a study that shows the brown pigment isn't just applied to the surface or cuticle portion of the egg but is applied throughout the calcification process.
https://academic.oup.com/ps/article/92/10/2783/1551175
This study is just for commercial brown layers so doesn't address heritage and dark layers' eggs. Those birds could have other pigments that are applied in greater densities and perhaps earlier in the shell building process than commercial layers or the production reds and other breeds the commercial breeds were developed from.
Sadly, I don't know of any research into the pigment makeup of dark layers.

 

[Brahma Chicken5000]

Legbars have white lobes and lay blue eggs.
I don't believe lobe color is linked to egg color at all.

Earlobe color and egg color are not linked although almost all chickens with white earlobes lay white eggs and almost all chickens with red earlobes will lay brown eggs. Which brings me to some new questions: Have you ever bred a chicken with white earlobes to a chicken with red earlobes? What color were the offsprings’ earlobes? Does it appear that white earlobes are dominant to red earlobes or vice versa?

 

[The Moonshiner]

I don't believe either white lobes or red lobes are dominate over the other.
I've crossed white with red and some offspring were white some were red but most were a mix showing red with varies amounts of white.
I'm not sure how its supposed to work.

 

[ChickenCanoe]

Brown egg layers actually have red earlobes, not brown.
I usually don't cross birds but I did cross a Penedesenca with a Welsummer and a Minorca.
I just don't remember what color lobes the Pene X Welly had.
With Penedesencas and Empordanesa, the white is more of a white cover over red lobes.
That white can be lost with poor breeding just like dark egg pigments can be lost over time.

 

[Brahma Chicken5000]

Brown egg layers actually have red earlobes, not brown.
I usually don't cross birds but I did cross a Penedesenca with a Welsummer and a Minorca.
I just don't remember what color lobes the Pene X Welly had.
With Penedesencas and Empordanesa, the white is more of a white cover over red lobes.
That white can be lost with poor breeding just like dark egg pigments can be lost over time.

My bad I meant red earlobes

 

[ChickenCanoe]

I knew you did. I just didn't want another reader to get the wrong idea.
I do that too. You get colors in your mind and that color keeps coming to mind.

 

[Brahma Chicken5000]

I knew you did. I just didn't want another reader to get the wrong idea.
I do that too. You get colors in your mind and that color keeps coming to mind.

I didn’t even realize I wrote brown earlobes until you pointed it out. I was thinking red earlobes but wrote brown because I had just wrote brown eggs

 

[Brahma Chicken5000]

@The Moonshiner I know that both the pea comb and the rose comb are dominant but what if I breed a rose combed chicken to a pea combed chicken, what type of comb will their offspring have?