One of the common issues with regard to backyard flocks relates to poor or inadequate feeding programs that can lead to vitamin and mineral deficiencies for the birds. Vitamins and minerals are very important components of a chickens diet and unless a formulated ration is feed, it is likely that deficiencies will occur.
Poultry require all known vitamins except C. Some vitamins are soluble in fats, while others are soluble in water.