Crested duck breeding...

[learycow]

That is so cool! So, I looked up the genetics, because I LOVE genetics. And, the crested gene is a dominant gene. The single dominant gene makes crested. Two crested genes results in a dead duckling.

Thus, any duck which doesn't look crested, isn't.

Breeding two crested ducks together will result in an average of twenty five percent of the ducklings dying. Fifty percent of the ducks will have a crest. Twenty five percent of the ducks will be normal (no crested gene).

Bred to a duck with no crest, the results are fifty percent crested and fifty percent non crested.

Thus, there is no point in breeding two crested ducks as there is no increase in crested offspring. Plus, who wants to breed ducks knowing that a quarter of them are going to be fatally deformed?

There is no such thing as a duck with two crested genes, since that is fatal. So, if you breed your duck to a non crested duck, you very well may end up with a good proportion of crested offspring and there is almost no chance that the offspring will have the fatal double dose of the crested gene.

I say almost no chance because, as you've observed, the gene can occur spontaneously.

BUT SO COOL!!!!

This isn't entirely correct. As ducks CAN carry the crested gene and not show it. And therefore produce it when mated properly.
And crested to crested will produce crested, higher chances of LARGER crests too which is why some people do breed this way.

 

[chickens really]

Here’s the pretty little one! He is soooo sweet and loves to snuggle. This was a few weeks old, he is now growing in adult feathers and looks so sillyView attachment 1479008

His crest is tiny...

 

[dotporter]

This isn't entirely correct. As ducks CAN carry the crested gene and not show it. And therefore produce it when mated properly.
And crested to crested will produce crested, higher chances of LARGER crests too which is why some people do breed this way.

Oh that's neat. When I researched it, every resource stated that the crested gene is dominant, and two copies are always fatal. Is there, then, a recessive form of crested? Or some other mechanism that I'm missing.

If you could point me in the right direction, I'd love to take a look.

 

[learycow]

Oh that's neat. When I researched it, every resource stated that the crested gene is dominant, and two copies are always fatal. Is there, then, a recessive form of crested? Or some other mechanism that I'm missing.

If you could point me in the right direction, I'd love to take a look.

Yes. As you can produce crested ducks from non crested flocks. Which means it is recessive as birds can carry it and not show it. But produce offspring with it

 

[dotporter]

Yes. As you can produce crested ducks from non crested flocks. Which means it is recessive as birds can carry it and not show it. But produce offspring with it

OH ok, I get you. No, the crest is absolutely a dominant gene. But, it's origin is a spontaneous mutation. This is why you can see it pop up in a population which isn't crested.

While I don't have crested, I'm familiar with the spontaneous occurrence of genetic mutation. I've had ducks which produce dwarfism. For some reason I even had one hen who repeatedly produced dwarfs. Sure it was maybe one every other year, but she was predisposed to it. Probably a flaw in her own genetics which repeatedly produced mutation.

That isn't common, nor typical. Usually spontaneous mutation is just that. One time.