Micro-Organisms as Feed Additives – Probiotics

For many decades antibiotics (so called growth promoters) have been used as feed additives in various species of farm animals, to reduce the frequency of diarrhoea under certain conditions. Furthermore, in most cases performance parameters like body weight gain or feed conversion ratio improves to up to 5%. These beneficial effects of feed antibiotics are generally explained by modifications of the intestinal bacteria and their interaction with the host animal, including bacterial interactions with intestinal tissue (turnover of epithelial cells, surface coating – formation and secretion of mucins, cell invasion and resulting lesions) as well as the immune system (response of the lymphocyte population and formation and secretion of immune globulins). Thus, the intestinal microbiota is not only involved in nutrient conversion along the gastrointestinal tract, but may also affect or support animal health.