Vitamins are trace organic nutrients which occur in feedstuffs in varying quantities and different combinations. Vitamins are required for growth, reproduction, and the maintenance of health. Vitamins are separated into two groups, fat soluble and water soluble. Fat soluble vitamins are associated with fat during digestion and absorption and include vitamins A, D, E, and K. Since these vitamins are stored in the liver and fat tissue, there is no recommended daily requirement. Vitamin A is required for the health and functioning of the skin and the lining of the digestive, reproductive and respiratory tract. Vitamin D is required for the absorption of calcium and phosphorus. Vitamin K is involved in the body’s blood clotting mechanism. And vitamin E is an antioxidant and is involved in maintaining muscle structure.
There are nine water soluble vitamins which include all of the B vitamins and vitamin C. These nutrients are soluble in water and are not stored in the body. As a result, a daily requirement of these vitamins in needed in the diet. B vitamins are involved in energy metabolism as well as other areas of body development. Unlike humans, poultry can synthesize vitamin C and therefore is not required in the diet.
Many feedstuffs provide a portion of these vitamins in the diet. However, a vitamin premix is typically added to the ration to provide additional supplements such as vitamin A, B12,D, E, K, riboflavin, niacin, pantothenic acid, and choline.
The mineral portion of feed is inorganic matter. There are 22 metal elements known to be required by animals. Classification of minerals is based on the amounts needed in the diet. Macrominerals are minerals normally present at greater levels in the body or needed in relatively large amounts in the diet. These include calcium, phosphorus, sodium, chlorine, magnesium, potassium, and sulfur. Microminerals or trace elements are normally present at low levels in the body or needed in very small amounts in the diet. Some of these include copper, iron, manganese, iodine, zinc, and cobalt.
Minerals are involved in a variety of functions in the body. Some of these include structural components of the skeleton (calcium and phosphorus), oxygen transport (iron), nerve transmission (sodium, potassium, and chlorine), and component of enzymes (zinc, copper, and manganese). Grains are low in minerals so dietary supplements are required. Calcium, phosphorus, and salt are needed in the largest amounts. Typically defluorinated and dicalcium phosphates provide additional calcium and phosphorus needed in the diet. Limestone is often used as a source of calcium. A mineral premix is typically used to supply trace levels of minerals to the diet.