RIR x White Leghorn cross question.

[LikeTurkeys]

I was playing around recently with the Kippenjungles chicken genetics calculator, and out of curiosity, I put in a Rhode Island Red male crossed over a White Leghorn female. Now, I've made this cross with my own birds before and chicks have always hatched out white with some red down. I'm assuming they would grow up to be white with red leakage.

I know that most hatchery White Leghorns (which is what my birds are), will have at least one copy of the dominant white gene. If I assume that, according to the calculator, half of the chicks hatched should be black (which actually leads to another question, where is the black coming from?). Since they are all hatching white with red leakage, can I assume that my White Leghorns have two copies of the dominant white gene? If I did assume that, the calculator's result is that all of the chicks would be white. Dominant white is a 'leaky' gene though so that would explain where the reddish down is coming from.

Ok, so back to the original cross placed in the calculator. Where do the all black offspring come from? Maybe I am missing something quite obvious here... looking forward to someone shedding some light on the situation!

Thanks!

 

[RoostersAreAwesome]

Most chickens with one copy of dominant white are black under the white. Dominant white is dominant over black. If a chicken only has one dominant white gene, then it’s only passed to half the offspring, and the others get the black underneath.
Also, if you didn’t already know, I don’t believe the calculator accounts for leakage.

 

[LikeTurkeys]

Most chickens with dominant white are black under the white. Dominant white is dominant over black. If a chicken only has one dominant white gene, then it’s only passed to half the offspring, and the others get the black underneath.
Also, if you didn’t already know, I don’t believe the calculator accounts for leakage.

I did know that, thanks. Thanks for the explanation of black under white! Can it be another color?

 

[RoostersAreAwesome]

I did know that, thanks. Thanks for the explanation of black under white! Can it be another color?

Occasionally they will have barring, blue, or splash underneath.

 

[The Moonshiner]

Hatchery white leghorns have two copies of dominate white. Dominate white doesn't cover gold/red tones so whatever is underneath doesn't have any of those.
Never had one that was self black underneath. I've heard blue or splash but I think that would be extremely rare if at all.

 

[RoostersAreAwesome]

Hatchery white leghorns have two copies of dominate white. Dominate white doesn't cover gold/red tones so whatever is underneath doesn't have any of those.
Never had one that was self black underneath. I've heard blue or splash but I think that would be extremely rare if at all.

Dominant white can exist by itself with no black underneath? I didn’t know that. But only as long as it has two copies?

 

[The Moonshiner]

What do you mean? Exist by itself? Any bird can have dominate white. I know its common to have black underneath but I don't believe its common for leghorns to. Also not unheard of to have blue or Splash with other breeds but don't believe that would be the case with leghorns. Pretty much unheard of to have leghorns with blue genes in the states.
I've seen barred and silver duckwing only myself.
Dominate white doesn't cover gold/ red tones so if you put it over anything with those then it shows. Like dominate white over gold duckwing makes pyle.
Its also said there's some buff breeds that have dominate white but when they do it doesn't show at all.

 

[RoostersAreAwesome]

What do you mean? Exist by itself? Any bird can have dominate white. I know its common to have black underneath but I don't believe its common for leghorns to. Also not unheard of to have blue or Splash with other breeds but don't believe that would be the case with leghorns. Pretty much unheard of to have leghorns with blue genes in the states.
I've seen barred and silver duckwing only myself.
Dominate white doesn't cover gold/ red tones so if you put it over anything with those then it shows. Like dominate white over gold duckwing makes pyle.
Its also said there's some buff breeds that have dominate white but when they do it doesn't show at all.

I mean it can genetically just be dominant white instead of dominant white over black. I thought dominant white had to cover something, like recessive white does.

 

[The Moonshiner]

Its just a gene in a slot. A bird can have one copy, two copies or no copies regardless of any other genes it has or doesn't have.
The combination of all the genes determines if it shows, doesn't show or where it shows.

 

[Maiahr]

I have this cross. RIR rooster, which I hatched last year from imported eggs and White Leghorn hen which I hatched - I bought the eggs from a hatchery. The little pullet hatched December 21st last year. She has some black spots which surprised me, no red at all (disappointing). The baby chicks are from the same parents, hatched Jan 22nd, most are white with one or two having black spots, but obviously still too early. Do you happen to know what colour eggs will they lay?