The nutritional status of animals affects their immune functions and resistance to diseases. Hence, nutrition deficiency can cause damage to the animal’s immune system and its organs. Therefore, the nutritional level of an animal diet has an important influence on immune function. Nucleotides and beta-glucan (as well as yeast organic trace elements) are important, immune-enhancing nutrients in yeast. Thus, the supplementation of nutrients through yeast-based products is key to improving animal immune health.