Breeding for olive eggs, why cross dark brown roo over blue hen and not the other way around?

[CurvyCoop]

I've always been told that the best way to create an olive egger is to use a blue laying hen and cross her with a roo with dark brown egg genes. Why is that? Why does it work better than the other way around, with a dark brown laying hen and a blue gened roo? In the end the offspring still receives a blue gene and a dark brown gene from it's parents. Or do chicken genetics work in such a way that it matters which parent supplied which gene and that it affects gene expression in the offspring?

 

[DarJones]

Some of the genes for porphyrin are sex linked, so yes, it does matter which sex is the female parent.

 

[nicalandia]

I've always been told that the best way to create an olive egger is to use a blue laying hen and cross her with a roo with dark brown egg genes. Why is that? Why does it work better than the other way around, with a dark brown laying hen and a blue gened roo? In the end the offspring still receives a blue gene and a dark brown gene from it's parents. Or do chicken genetics work in such a way that it matters which parent supplied which gene and that it affects gene expression in the offspring?

Many Polygenic traits like egg color, egg laying have some of those genes located on the Z sex chromosome.

 

[Know it All]

I've always been told that the best way to create an olive egger is to use a blue laying hen and cross her with a roo with dark brown egg genes. Why is that? Why does it work better than the other way around, with a dark brown laying hen and a blue gened roo? In the end the offspring still receives a blue gene and a dark brown gene from it's parents. Or do chicken genetics work in such a way that it matters which parent supplied which gene and that it affects gene expression in the offspring?

It doesn't matter which parent supplies the gene. It's just that with hens, it's easier to see which genes they carry because there are more clues; not only feather coloring and comb shape, but also the eggs. I hope that answers your question!
Edit: I do believe there are certain genes (such as speckling) that carry better through the cockerel than the hen.... I'll look more into it! You've definitely piqued my interest!!

 

[The Moonshiner]

It doesn't matter which parent supplies the gene. It's just that with hens, it's easier to see which genes they carry because there are more clues; not only feather coloring and comb shape, but also the eggs. I hope that answers your question!
Edit: I do believe there are certain genes (such as speckling) that carry better through the cockerel than the hen.... I'll look more into it! You've definitely piqued my interest!!

What does feather coloring have to do with what egg shell genes a chicken has? And what would it matter even if it did? Males have feather coloring too, right?

 

[Know it All]

What does feather coloring have to do with what egg shell genes a chicken has? And what would it matter even if it did? Males have feather coloring too, right?

I'm sorry, I may have misspoken. We're all learning here. I'll have to ask around.... for some reason I feel that feathering impacts egg color. Do you know anything about that? I know that the coloring of the egg can (sometimes) be predicted based on feathering/earlobes. Not all the time, but to some extent.

 

[The Moonshiner]

I don't know of any link between feather colors/patterns and egg shell color. And I know earlobe color isn't linked.

 

[nicalandia]

I'm sorry, I may have misspoken. We're all learning here. I'll have to ask around.... for some reason I feel that feathering impacts egg color. Do you know anything about that? I know that the coloring of the egg can (sometimes) be predicted based on feathering/earlobes. Not all the time, but to some extent.

This información is incorrect. There is no link between feather color and egg color, neither earlobe color and egg color. The only external link between egg shell color and another visible trait is between Pea comb allele(P and p+) and the blue egg shell mutation Oocyan which are located on the same chomosome very close to each other

 

[DarJones]

At least one gene in the porphryin biopath is on the W/Z sex chromosome pair. Slow feathering is on the W/Z sex chromosome. Therefore if certain feather types are desired in the offspring combined with porphyrin production, it would make more sense to make the cross in one direction than the other. This is why my original cross between Silver Laced Wyandottes and blue egg laying Brown Leghorns had to be with a SLW rooster to a brown hen. I needed the slow feathering gene fixed as early as possible. I am still having to select for slow feathering as the trait takes several generations to stabilize. Just pointing out that feather color may not be linked, but feather configuration is.

If I didn't make this clear enough, SLW have slow feathering which is required to get optimal lacing. I want full lacing in a SLW type chicken that lays pure blue eggs.

 

[nicalandia]

At least one gene in the porphryin biopath is on the W/Z sex chromosome pair. Slow feathering is on the W/Z sex chromosome. Therefore if certain feather types are desired in the offspring combined with porphyrin production, it would make more sense to make the cross in one direction than the other.

The Z chromosome is quite Large, there is no linkage between Sex linked Slow/Fast feathering and Sex linked Porphyrin genes.