double yoke eggs

I have had a few 17gm double yolkers. Usually from new layers.

 

Never had this happen but sounds interesting. I've always wondered if a double yolker is fertilized would both yolks be fertilized or just one? Or can doubles even be fertilized since they are technically considered mishap eggs? Would it grow two babies? Would be interesting to know if anyone has ever tried it...

 

On my last hatch I did have a double yolk that made it to full term but the chicks never hatched. I opened the egg after the rest had hatched and there was two full term normal looking chicks but I guess they suffocated because they both couldn't pip into the air sac.

 

Amazing. I have heard of this

 

There are several threads on the BYC incubating forums about hatching double-yolkers. They do produce twins, but most often they're not able to hatch successfully (with some notable exceptions). In the event that one baby dies along the way inside the egg, the other would die also, as it wouldn't be able to process the excess waste and bacteria produced by its dead companion. Likewise, in the event of only one yolk fertilized, I'd think the second yolk would eventually go putrid and kill the other.

Do a quick search for "double yolker incubation" and see what you turn up.

 

Here is a picture of one of the 17gm ones. I have never tried to incubate any that big as all I have read about doing so it very rarely ends well.

 

I've heard stories of double yoked eggs hatching out birds with a 3rd leg growing out their butt or other crazy deformities.