Using Dark Cornish in White Cornish breeding

[Redhead Rae]

Someone in a Cornish FB group posted a picture of a Bantam cockerel and pullet that were white with flecks. He said that they were Whites crossed with Dark (didn't say which were the hen and which the cockerel). He said he was using them to add genetic variation to his Whites and got a few Blacks out of the breeding as well. I asked him to explain how that works, but he never answered. Does anyone else know how the genetics of Dark Cornish coloring works? I've done some research but I haven't been able to find anything.

FYI: I have LF Darks and I have a few LF white eggs due to hatch this week.

 

[Redhead Rae]

Just tagging you @The Moonshiner because you are VERY knowledgeable about color genetics.

 

[The Moonshiner]

I've never raised cornish so don't know much about them.
I was thinking dark were black laced red and white were recessive white but don't know.
It really doesn't make sense though.
When you say white chicks with specks it sounds like the whites were dominate white so chicks got one copy and specks are bleeding through.
If that was the case he shouldn't have gotten any black chicks.
I also don't know what's under the white in white cornish. It makes more sense they would be recessive white as it hides everything and dominate white doesn't hide red so they couldn't have red anywhere underneath if dominate white.
The way it could work is that the whites were two genes for recessive white and one copy of dominate white.
The white would pass on one recessive white gene to all chicks but it wouldn't be expressed.
Half the offspring would get dominate white explaining the white with speck chicks.
Half the offspring wouldn't get a dominate white gene which would explain the black chicks.
Now I don't know what is under the white and I don't know a lot about crossing laced patterns so with the unknown and the black laced red in the mix would the chicks be black or would the lace genes not allow that?
Maybe they would hatch black maybe not.
Tag @Sneebsey I'm pretty impressed with their genetic knowledge.
Maybe they could help.

 

[Redhead Rae]

I've never raised cornish so don't know much about them.
I was thinking dark were black laced red and white were recessive white but don't know.
It really doesn't make sense though.
When you say white chicks with specks it sounds like the whites were dominate white so chicks got one copy and specks are bleeding through.
If that was the case he shouldn't have gotten any black chicks.
I also don't know what's under the white in white cornish. It makes more sense they would be recessive white as it hides everything and dominate white doesn't hide red so they couldn't have red anywhere underneath if dominate white.
The way it could work is that the whites were two genes for recessive white and one copy of dominate white.
The white would pass on one recessive white gene to all chicks but it wouldn't be expressed.
Half the offspring would get dominate white explaining the white with speck chicks.
Half the offspring wouldn't get a dominate white gene which would explain the black chicks.
Now I don't know what is under the white and I don't know a lot about crossing laced patterns so with the unknown and the black laced red in the mix would the chicks be black or would the lace genes not allow that?
Maybe they would hatch black maybe not.
Tag @Sneebsey I'm pretty impressed with their genetic knowledge.
Maybe they could help.

I think it depends on the breeder. Some are trying for recessive white and others want dominant to cover the White Laced Red and Dark that have been used in their breeding. I'm hoping for at least a pair out of my eggs. I have 6 in lock down, but I'm only hopeful about 3. So it would be hard for me to find more eggs this time of year to hatch more.