Spontaneous Mutations? Split-Comb, Tassle, All-White?

[heatherbeast]

Hi all,

I have an F2 Egyptian Fayoumi/Bielefelder mix that has expressed some surprising phenotypes. Usually I see black barring (autosomonal dominant from the Fayoumi) or auto-sexing barring (from the Bielefelders) in varying combos of barred buff, red, or white. To my shock and surprise, this most recent batch of chicks has thrown two little platinum chicks with a bit of buff around their heads.

I kept in touch with one of my buyers, who returned one of the chicks as it turned out to be a rooster. He is WEIRD. I have NEVER seen an all-white/cream bird before, and EVERYONE in my flock has a single comb. I joke that he is "the mailman's chick" because as far as I can tell, these traits shouldn't show up like this based on the parent stock. He does have absolutely gorgeous slate legs which are ALL Fayoumi, at least. He is sweet, perky, and has a WONDERFULLY friendly temperament, a complete 180 from his mom, who would do anything to get the &(#^ away from humans.

Does anyone else have experience with spontaneous white mutations? If so, do you happen to know what genetic loci those are related to? What about the tassle/split comb, have you ever had birds spontaneously express this?

For comparison, almost all of his siblings and half-siblings look like this:

WHAT is going on? Any insights?!

 

[CascadiaRiver]

Are you 1000% sure that there was no other birds that could have contributed the genes for that top knot on the roo? There could be ways to explain how he's solid silver, but crest is a dominant trait, so one of his parents would have had some sort of crest, even if small

 

[heatherbeast]

Are you 1000% sure that there was no other birds that could have contributed the genes for that top knot on the roo? There could be ways to explain how he's solid silver, but crest is a dominant trait, so one of his parents would have had some sort of crest, even if small

This is why I'm in a tizzy -- the only roos around are a Bielefelder from McMurray, and half Fayoumi-half Bielefelder. Mom is a purebred Fayoumi. The birds are in a run, and none of my neighbors have roos.

 

[NatJ]

This is why I'm in a tizzy -- the only roos around are a Bielefelder from McMurray, and half Fayoumi-half Bielefelder. Mom is a purebred Fayoumi. The birds are in a run, and none of my neighbors have roos.

This is definitely puzzling!

Can you post pictures of the parents? Is the Bielefelder the father of the half-Bielefelder?

 

[heatherbeast]

Granddad is a Bielefelder.

Grandma is a Fayoumi.

They produced these two fellas, one of which is the white chick's dad.

Who was totally smitten with 'mom', so the same Fayoumi dam is both mom and grandmother to the white chick... (note that the birds get taken out for photography, they don't actually free range).

 

[NatJ]

This is why I'm in a tizzy -- the only roos around are a Bielefelder from McMurray, and half Fayoumi-half Bielefelder. Mom is a purebred Fayoumi. The birds are in a run, and none of my neighbors have roos.

Just to check: no chance of any other hen being the mother? For example, a Buff Laced Polish could mate with one of those mixed roosters to produce a chick like your white one.

 

[heatherbeast]

Just to check: no chance of any other hen being the mother? For example, a Buff Laced Polish could mate with one of those mixed roosters to produce a chick like your white one.

I'm fine with answering questions to rule out, please don't be shy!

No crested or silkies in my flock. This chick came out of a white egg, Zully Monster (the Fayoumi) is the only white egg layer in my flock (everyone else is brown or blue egger). She is about 5 years old, would that increase the likelihood of genetic errors?

 

[NatJ]

I'm fine with answering questions to rule out, please don't be shy!

No crested or silkies in my flock. This chick came out of a white egg, Zully Monster (the Fayoumi) is the only white egg layer in my flock (everyone else is brown or blue egger). She is about 5 years old, would that increase the likelihood of genetic errors?

Hmm, definitely a puzzle there!

Assuming you are correct about the parentage, here are some thoughts that may or may not help:

Granddad is a Bielefelder.
View attachment 4162713

Grandma is a Fayoumi.
View attachment 4162714

They produced these two fellas, one of which is the white chick's dad.
View attachment 4162718

Who was totally smitten with 'mom', so the same Fayoumi dam is both mom and grandmother to the white chick... (note that the birds get taken out for photography, they don't actually free range).

I could almost believe I see a bit of a crest on the Bielefelder (little puffs of feathers on the sides of the comb), but I don't see it in either of his sons, so I don't know what to think there. If the Bielefelder had a crest, it could be passed to his son and then on to his grandson-- but I would expect to see it on the son, not just the Bielefelder and his grandson.

Given that Bielefelders do have the same coloring at Crested Cream Legbars (autosexing), I wonder if the hatchery had a mixup at some point, and a Crested Cream Legbar got crossed into their Bielefelder line? (If any pullets from white-egg or brown-egg hens, sired by the Bielefelder or his sons, lay blue or green eggs, that would be a pretty strong indication of Cream Legbar in there somewhere. But it would also be possible to get the crest and not the egg color if a cross happened several generations ago.)

I have noticed that some Crested Cream Legbar roosters do not seem to have visible crests, even when they have the crest gene, so I suppose that might be what happened to one or both of the mixed-breed roosters. But that doesn't explain how the white chick got such a big, obvious crest. (Maybe some kind of modifier gene is involved to control the size of the crest?)

The comb also reminds me of what the combs look like on Crested Cream Legbars. They have single combs, but the crest pushes the comb a bit forward, so it crinkles instead of being straight. So no matter where the crest came from, that might be an explanation for the odd-looking comb from two single-comb parents.

The fact that your odd colored chicks came from breeding a son to his mother makes me suspect that one or more recessive genes are involved in that.

The white color might come from the recessive white gene. That "should" not be in either Bielefelders or Fayoumis, but in this case I wonder if the Fayoumi hen does have it. If she does, and if one of her sons inherited it, then breeding that son back to her would give about 25% white chicks.

(If I knew of a recessive gene for a crest, I'd be suspecting the Fayoumi of having that too. But I have only heard of crest being caused by a dominant gene, which is why I was looking hard for possible crests in the parents.)

 

[CascadiaRiver]

My guess that instead of solid white hes solid silver, but the crest is the weird part

 

[RoostersAreAwesome]

I'm fine with answering questions to rule out, please don't be shy!

No crested or silkies in my flock. This chick came out of a white egg, Zully Monster (the Fayoumi) is the only white egg layer in my flock (everyone else is brown or blue egger). She is about 5 years old, would that increase the likelihood of genetic errors?

You’ve never had any crested birds?