Strange deformity?

[triplepurpose]

This is not precisely an emergency, I doubt it's a disease, doesn't seem to be an injury, and probably doesn't have a direct "cure," but I didn't know what other section to post this in, so forgive me:

I've noticed in a recent clutch of pullets and cockerels that we hatched (under a hen) and raised (outdoors with the main dual-purpose flock), that a least a few of the young birds are missing toenails on a least one, but usually several, toes. (If it seems odd to you that no one noticed before now, it's because these chicks weren't hand-raised, but were raised by their brood mother, and grew up with the rest of the flock and running all over in a big coop with multiple runs--so I've probably handled each one individually only a few times, and it never would have occurred to me to check that they had toenails!)

Anyway, anyone else ever seen this? Is this genetic, environmental, nutritional, the result of a pathogen, or what? None of them seems to suffer for it, and they have no other faults I can see. They are quite healthy and vigorous and behave normally (hence why this wasn't noticed earlier).

I'm curious, in part, because from a practical standpoint I'll have to decide soon whether to keep the pullets on to lay/breed (as I had hoped), or whether I'll need to cull.

 

[ChickensAreSweet]

I have noticed a few chickens missing toenails also over the past few years, from different sources (hatcheries). I believe personally that it is genetic but don't know...some things are tied to incubation temperatures and so you never know.

Sometimes it is no toenails on all the toes and sometimes just on one toe.

 

[triplepurpose]

These birds didn't come from a hatchery, and some of their parents did, but others were hatched on the farm. Yet only this clutch has this deformity. The feed and environment has remained the same. It's very strange!