I have a young chicken, about 5 months old. Two nights ago I noticed she was sitting on the floor of the coop instead of on the perch. She was on the floor again last night. Today I went to pick her up to check her out and she can't use her one leg. When she tries to walk it just hangs to the side and she has to shuffle. I moved her leg and felt it, it doesn't look or feel broke. I can see no injuries what so ever. They do free range so she could of gotten kicked or stepped on by one of the horses or cows, but I couldn't see anything that looked out of the ordinary. All the other chickens are fine. Could this be a vitamin deficiency or something. She's just a mix breed and looks like a big turtle dove. I feed them the layers crumbles, cracked and whole corn. I've put feed and water by her but don't know what else to do. Any suggestions would be appreciated.