One of our sexlink hens brooded a clutch of nine eggs and hatched out six of those on May 9. Now 16 days later, we discovered one of the chicks outside, alone, unable to move with a case of curled toes. Now perhaps I haven't done my research properly, but from what I can tell, this is a common reaction to vitamin B2, or riboflavin, deficiency.
Here's how I believe it happened. Momma hen has her six chicks with her foraging along side the other hens. Although I have tried to pull them aside and feed the chicks the normal chick starter/grower feed that we use for our replacement hens, it has been difficult to keep our egg layers from consuming it. As it is medicated, I don't want that feed entering our egg supply. The chick in question has always been the one to lag behind and more than likely is not receiving his fair share. My guess is that in the larger picture of our poultry set up, this little chick has simply not received adequate nutrition.
These links were helpful in doing my own diagnosis:
Merk Vet Manual
World Poultry
Backyard Chickens
Backyard Chickens
From what I could tell, if nutrition is corrected as soon as the deficiency is noticed by giving Poly Vi Sol infant vitamin drops, then it is possible to reverse the situation. We're not quite to 24 hours yet after starting this chick's recovery process, but it seems to have worsened instead. We can only hope that it will in time pull out, but frankly I'm not hopeful.
With our recent heavy bout of rain, it has been hard to keep tabs on the chicks as momma has had to keep them brooded to stay warm, and we have simply not been outside as much. Lesson learned I guess.
So what are we going to do to keep the other chicks healthy? I'm contemplating a design to allow the chicks to "creep feed" as is done with other livestock. The smaller, younger animals are able to access feedstuffs available for their consumption only and not by the older, larger animals.
Although we have not experienced this situation before raising chicks in a similar manner, it is a concern that we will need to address to keep it from happening again.
If you've had experience with a similar deficiency, leave me a comment. I'd like to hear what advice you have to offer.