chick underdeveloped/ slow grower?

[Teenyfarm]

HI! I have added French Black Marans to the flock this year and got 4 as day olds. The other 3 are nice and big at 6/7 weeks but I have one that was lagging FAR behind the others and her wing feathers were oddly curled up and looked pretty scrappy. At 4 weeks the size and development difference was only widening, she still looked hardly bigger than a day old chick and the others were feathering out and she was getting trampled when she tried to eat. So I separated her and purchased 2 new day old chicks to keep her company. She has finally grown but at the same size and development as the new ones. She is 6 almost 7 weeks old and looks like she is only a couple weeks old. She otherwise seems normal. I put photos, you can kind of see the scrappiness of her feathers but it's hidden now that she has feathered out a bit. Here is a pic of one of her sisters at full size and her for comparison.

What could be wrong, why is she developing so slow and will she catch up? Is this common with this breed?
I have given her chick start and scrambled egg as well.

 

[Debbie292d]

I breed, hatch, and raise a lot of silkies, and every so often, I'll see one I call a runt. The same thing happens...slow to grow, not looking the best, etc. These I presume would have been FTT (failure to thrive) chicks, or one that wouldn't have hatched, but because we took good care of them, they live.

You've been very nice to that one to get her same-size buddies! The only thing I didn't hear mentioned was vitamins. I think she needs to be on vitamin therapy for a month or so, and that should help her. She most likely will always be smaller though.

We use Poultry Cell or Nutri-Drench for vitamins, but any complete type vitamins are fine. I'd go for the ones that mix in water as it's easier and the others can get benefits of that too. I'd just do it every other day for a couple of weeks, then down to twice a week, and once a week thereafter.

 

[Teenyfarm]

I breed, hatch, and raise a lot of silkies, and every so often, I'll see one I call a runt. The same thing happens...slow to grow, not looking the best, etc. These I presume would have been FTT (failure to thrive) chicks, or one that wouldn't have hatched, but because we took good care of them, they live.

You've been very nice to that one to get her same-size buddies! The only thing I didn't hear mentioned was vitamins. I think she needs to be on vitamin therapy for a month or so, and that should help her. She most likely will always be smaller though.

We use Poultry Cell or Nutri-Drench for vitamins, but any complete type vitamins are fine. I'd go for the ones that mix in water as it's easier and the others can get benefits of that too. I'd just do it every other day for a couple of weeks, then down to twice a week, and once a week thereafter.

Thanks for the info! The chick start liquid I bought doesn't seem to have as many vitamins as the poultry cell so I think I'll try that. Thank you!