A feed additive is a food supplement for farm animals that cannot get enough nutrients from regular meals that the farmers provide and include vitamins, amino acids, fatty acids, and minerals. 
In some cases, if an animal does not have some specific nutrition in its diet it may not grow properly. The nutritional values of animal feeds are influenced not only by their nutrient content but also by many other factors. These include feed presentation, hygiene, digestibility, and effect on intestinal health. Even with all of the benefits of higher quality feed, most of a farm animal's diet still consists of maize, wheat, and soybean meal because of the higher costs of quality feed