Beak Birth Defect - Input Needed

[Buns]

I do not hatch my own chicks, I deliver the eggs and then pick up the chicks after hatch. My hatcher friend noted that of the three peafowl eggs I brought her, two hatched within hours of each other. The third chick continued to cry, but never pipped. Because it continued to cry and apparently showed signs of wanting to live, she helped it out of the shell forty eight hours after the other two chicks were born. She was shocked to find that it had no upper beak at all.

I have not encountered this type of defect before in any type of poultry although I heard of it once with a parrot who received a prosthetic beak. The peachick died within hours of his birth and unfortunately she didn't think to take a picture of it. I wondered how common this defect occurs. Any input would be appreciated. Is it due to a fluke, or line or inbreeding possibly?

Our adult breeders are on a high quality game bird feed (crumble) and receive scraps from the house when evailable. We have not wormed or medicated any of the birds during the breeding season.
Thank you!

 

[Kedreeva]

I know beak deformities are fairly common in poultry (missing portions of beaks, crossed beaks, under/over bites, malformed beaks) and can be due to incubation inconsistencies or handling of the eggs at certain times. It can also just be a fluke- I don't think it's strictly genetic, but keep track of who lays what and what hatches just in case. If you notice a hen hatching chicks with deformities, you may want to remove her from the breeding pool, or don't hatch her eggs.