Vitamins, unlike carbohydrates, fats and proteins, are found in limited amounts in natural feed materials. Therefore, in order to maintain the normal physiological function of animals, artificial vitamins are often used in animal feed.
According to the nutritional needs of different animals, feed enterprises generally mix a variety of vitamins into multi-dimensional premixes, and then mix them with other feed materials and feed additives to make compound feeds for animals to eat directly.
The known ten vitamins can be roughly divided into fat soluble vitamins and water soluble vitamins. Vitamin A, vitamin D, vitamin E and vitamin K belong to fat soluble vitamins, while vitamin B and vitamin C belong to water soluble vitamins. After being absorbed by the intestine, the water-soluble vitamin is circulated to the tissues needed by the body. Most of the excess is excreted by urine, and very little is stored in the body. Fat-soluble vitamins are absorbed by the small intestine after bile emulsification, and enter the organs in the body from the lymphatic circulation system. Excess fat-soluble vitamins can be stored in the body. Vitamins A and D are mainly stored in the liver, while vitamin E is mainly stored in adipose tissue.
The physiological functions of vitamins are important, but more is not always better. Long-term intake of vitamin A tends to accumulate in large quantities in the body, which may lead to poisoning symptoms such as bone decalcification, joint diseases, dry skin and decreased intake.
