Is there an explanation?

[BlueCamas]

In my first attempt at hatching eggs, I managed to hatch out one chick (more may hatch soon, but I'm doubtful). I was so excited until I saw he had light feathering on his legs

His parents are purebred Bantam Plymouth Rocks, I only have one rooster and I'm positive that the eggs was from one of my Bantam Rock hens. What could have happened? Plymouth Rocks should not have feathered legs! The chick is blue with a single comb, like a Rock should be, but his legs!
Can anyone explain this to me? I am going to cull him regardless, but I would like to know why this happened. I want to sell hating eggs and chicks in the future, but wouldn't want to sell them with the possibility mutation.
I will post pics tomorrow so you guys can have a better look.

Also, one of my Rock hens hatched out 3 of her own eggs all BBS Bantam Plymouth Rocks and all with clean legs. Unfortunately, none made it, but I'm hoping that this chick was just a fluke.

 

[Illia]

Are they from good stock that fit the SOP quite well? I find that some blues out there are a little questionable, considering also how new the color is in Rocks.

But that aside yes it can happen, even in a long-closed flock. I don't know how or why but if you got it from a not-so-closed flock/lineage it might be a recessive thing. Or it just might be a fluke. If you get it again I say track down the mother hen, cull her, and the rooster who sired the feather-shanked offspring.

I've had Ameraucanas with lightly feathered shanks. Not fun. It was a recessive trait in that case, but I've heard of it happening out of the blue too.

 

[BlueCamas]

The only main issue with culling the parents is that I only have a trio, so that would leave me with one hen. I will be setting a dozen+ eggs from them next week and I'll see if anything like this turns up again.
I think they are so-so quality. The main thing I will be working on is leg color in the blues and longer backs over-all.
I am hoping to get more adults this spring and if the feathered shanks turns up in more chicks than I will boot the parents when I have some to replace them.

 

[BlueCamas]

Here's a pic of the chick's legs. The other remaining egg hatched and low and behold FEATHERED LEGS!!! It has even less feathering than the first chick, but it's still feathering

Grrrr, I'm going to do one more hatch, but if I still get a majority of chicks with feathered legs, the parents are going bye-bye.

First chick

The possible parents with the first chicks that all had clean legs