Question:  query regarding some broiler showing the signs of lameness & attempting to huddling together 
Answer:  increase the temperature of the premises by increasing the nos of light, uniform distribution will indicate the optimum temperature, for lameness -if possible,  decrease the maize portion in the broiler feed for some days,[ use biovit poultry formula plus ] vitaplex -10 ml / 100 nos of bird for 3-4 days with drinking water