Buff Orpington roo on Cuckoo Marans sex linked questions

[chickenmama22]

I incubated eggs from a Buff Orpington roo on Cuckoo Marans hens. Only one hatched successfully and I would like to know if it's a girl or boy. Here's what he/she looks like:








Has anyone done this type of cross? I have read that it's sex-linked; I've searched all over the byc site and haven't found anything about what the cockerels vs pullets look like at hatch.

Thanks in advance!
Nancy

 

[aoxa]

You are positive that it is fathered by the orp and mothered by the marans?

 

[chickenmama22]

Yes, quite sure. Buff Orp roo, Cuckoo marans hen. It looks a lot like the offspring of a Cuckoo Marans roo on Buff orp hen. The chick's face looks like the BO, but with a dot on the head. The fuzz has a black "undercoat."

I didn't mention that the 2 chicks that pipped, did so at the middle of the shell and seemed to be upsidedown in the shell (breach?) with huge tummies, too. The other hatchling's yolk was protruding and didn't survive. I've made some temperature adjustments, so hopefully the next batch will do better.

 

[chickenmama22]

I just found this info:

Buff (e.g. Buff Orpington) roosters with cuckoo/barred hens will produce:
Cuckoo/barred cockerel chicks (in brown or grey tones). The hens will be either solid brown or solid black sex link chickens.
Source:
http://www.small-farm-permaculture-and-sustainable-living.com/black_sex_link_chickens.html

Would this chick be "solid brown" and therefore female?

 

[aoxa]

50% Pullets, black unicolor
50% Cockerels, black unicolor barred
This is what I get when I enter the two in the chicken calculator. I didn't think they would look anything but black as chicks.

https://www.backyardchickens.com/t/261208/sex-linked-information

 

[aoxa]

Black Sex-linked

There are two important genes that must be a part of a black sex-linked cross; the E locus allele called extended black (E) and the sex-linked barring gene (B). The Barred Plymouth rock carries both E and B and both genes are used as the female side in commercial black sex linked crosses while the male side of the cross is a Rhode Island Red or a New Hampshire. Birchen birds at times can be used in black sex linked crosses. It is best to leave the use of birchen birds to individuals that have tested the birds for the correct genotype. If birchen birds do not have the correct genotype, the offspring will not be black sex linked.

A few specifics to remember about a black sex-linked cross are:

1) the female must carry sex-linked barring (barred),

2) the male can not carry sex-linked barring (male can not be barred),

3) one of the birds must be homozygous for extended black or carry two extended black genes and

4) neither of the birds can carry dominant white or in other words be a white bird. Some recessive white birds may work on the male side of the cross but you never know if it will work or not work. So I suggest not using white birds.

5). Almost any variety (color) of male ( not including white or barred ) can be used in a black sex linked cross. White birds sometimes carry dominant white and or barring which would not work in a black sex linked cross. White males that do not carry dominant white or barring will work as the male in a black sex linked cross. White males like the white wyandotte or the white plymouth rock will work if they do not carry dominant white or barring.

In a black sex-linked cross, the female will only contribute the barring gene to the male offspring. So the adult males will be black and barred. The female offspring will receive their sex linked trait from the father; in this case, the recessive gene for no barring. So the females will not be barred as adults.

It is also important that the chick down has a black dorsal surface, back and top of the head; this allows for the barring gene to be expressed as a white or cream spot on top of the male chicks head. See Illustration 5. This is why a white bird that carries dominant white can not be used to produce black sex linked chicks. The top of the head would be white and the white spot will not show. Males that carry barring can not be used because the males will produce females chicks with white spots on their heads.

The top of a female chicks head will be a solid black colour. See Illustration 6. The chicks in the pictures do not have a white belly like many other black sex linked chicks.

Illustration 5 male black sex-link

Illustration 6 female black sex-link

Examples of breeds that can be used for black sex linked crosses.

 

[farmerChef]

it has a white spot on its head, so its a male. It looks similar to my barred lemon blue chicks

 

[chickenmama22]

Thanks!

I think it's interesting that when I hatch pure Cuckoo Marans, the chicks all have a spot on their heads. I tell the males from females by the color of their backs -- the black ones are females and the grayish ones are males. I *thought* I'd know by the dot on their heads. Granted some of the pure Marans chicks I raise have yellowish dots and some have white ones, but I haven't paid enough attention to see if there's a connection between dot color and gender.

That chick is starting to get some feathers. I'll wait a few more days and take a picture. Maybe that will help.

 

[LAFreewayChickens]

I would guess the dot color difference is gold or silver gene. (There as gold and silver CM). You could theoretically use it in a (red) sex-linked cross, but it would be hard to get a reliable read on such a small area. Plus you'd have to be sure the roo was homozygous for gold.

That said, if you have a gold CM roo (he'd have gold on his hackles: http://www.feathersite.com/Poultry/CGK/Marans/GoldAndSilverCuckooMaranPs.JPEG), and (only) silver cuckoo hens, you could keep track of the relationship of dot color and sex. If the roo was homozygous for gold, the girls would have yellow spots and the boys would have white spots. If you established that was consistently the case, you could use it to sex at hatch. (In addition to size/shape of spot).

 

[nicalandia]

I would guess the dot color difference is gold or silver gene. (There as gold and silver CM). You could theoretically use it in a (red) sex-linked cross, but it would be hard to get a reliable read on such a small area.

Silver Or Gold is not expressed on Extended black background, any cream or white regions found on E chicks(Extended Black) including the headspot(barring) is only representing the delayed migration of aumelanoblasts not an expression of S or s+