At present, a variety of vitamins are added to the feed to ensure the healthy growth of animals. If an animal is completely deficient in one or several vitamins, or if the intake is insufficient, some metabolic processes will be damaged, resulting in stunted growth or disease. Niacin, also known as niacin, is a vitamin involved in the enzyme system of the body. It plays a major role in the metabolism of carbohydrates, fats and proteins in the body. When the body lacks niacin, it can cause metabolic disorders. Folic acid is a B vitamin widely found in green vegetables. Lack of folic acid can make chicks grow poorly, have abnormal feathers, anemia and osteoporosis. This experiment refers to GB/T17813-1999 "Determination of Niacin and Folic Acid in Compound Premix" to determine the compound premix of 4% laying hens. Attachment download