Vitamin B3 (niacin/nicotinamide) is an important water-soluble vitamin in animal feed. As a key component of coenzymes NAD and NADP, it is widely involved in the body's energy metabolism, protein synthesis, and cell repair processes. In animal husbandry, vitamin B3 can promote the utilization of carbohydrates, fats and proteins by animals, enhance feed conversion rate and growth rate. Maintaining the health of the skin and digestive system may lead to problems such as pellagra in pigs, oral inflammation and poor feather growth in poultry, and decreased forestomach function in ruminants when lacking. It also has a positive effect on maintaining reproductive performance and alleviating stress. Since most animals do not synthesize enough on their own, especially during the rapid growth period or under high-grain diets, they must be supplemented with feed to meet their needs