Curled toe paralysis disease in poultry is caused by

Curled toe paralysis disease in poultry is caused by Deficiency of vitamin-B₂.
Curled toe paralysis is a low riboflavin diet that may cause two types of nutritional deficiency. One of these produces a rapidly acute paralysis characterized as neuromalacia and a more slowly developing form that causes 'curled toe' paralysis in the growing chick.
The signs and symptoms of riboflavin deficiency include skin disorders, hyperemia and edema of the mouth and throat, angular stomatitis, cheilosis, hair loss, reproductive problems.