What causes double yolked eggs??

[Routhfamilyfarm]

I have twelve hens that are starting to lay for the first time. It seems like I have one hen laying double yolked eggs only (not sure which one though), and I've also seen one from one of my Easter Eggers as well. Its not my first time starting a flock, but certainly the first and only time I've had so many doubles...Don't get me wrong, I think its awesome. I'm just curious what cause it???

 

[oldhenlikesdogs]

I think something like the yolk gets made but doesn't move through like it should and the next yolk catches up, so two yolks travel together through the oviduct getting made as one, something like that, sounds like a strange movie plot.

 

[aart]

Two yolks get released instead of just one......
.....common with new layers and more common with high production hybrid breeds.

Can't remember of this video addresses double yolkers Egg Formation Video