Phytogenics are materials of plant origin such as herbs, spices, essential oils or plant extracts. They are already used for thousand of years as flavors, food preservatives and medicines The oldest written evidence of medicinal plants usage for preparation of drugs has been found approximately 5000 years ago on a clay tablet.
Since the discovery of penicillin and its use in humans, the use of herbal products, pure for its health sustaining properties, has been put in the background. Years after the discovery of the first antibiotics, people already found out that dosing antibiotics in sub-therapeutic doses improved growth and feed conversion efficiency, especially when the animals were kept in non-optimal circumstances. Instead of using the term antibiotic, people started calling them “antibiotic growth promotors or AGP’s”. Improvements in growth were estimated to be between 4 and 8% while feed utilization was improved by 2 to 5%. The explanation of this effect is probably linked with an antibacterial action and therefore a decreased intestinal competition for nutrients, although there is also a theory that AGP’s decreased the proinflammatory response.
Around the same period as the discovery of the growth promoting effect, researchers found that dosing antibiotics in substherapeuthic doses induces an increase in microbial resistance. Nevertheless, it was not before 1986 that the first country, Sweden, prohibited the use of antibiotics as growth promotors. Since the 1st of januari 2006, there is a ban for AGPs in the entire European Union. In other countries and states, the use of antibiotics in livestock feed for non therapeutic use is under great scruteny, partially due to an increasing consumer awareness of the growing problem of the development of “superbugs”. Nowadays, consumers are more aware of the benefits of healthy food, and are putting more and more pressure on the market for antibiotic –free animal production system.
Alternatives for antibiotic use had to be found and the use of phytogenic products have become popular again. Although this is not the only alternative for antibiotics, it is one of the more interesting pathways.
References: Dibner, J.J & Richards, J.D. (2005). Antibiotic growth promotors in agriculture: history and mode of Action. Poultry Science, 84: 634-643.
