PHYTOBIOTIC IN POULTRY NUTRITION AS AN ALTERNATIVE TO INFEED ANTIBIOTICS: A REVIEW ARTICLE
Photobiotic are contained a wide range of compounds derived from plants such as essential oils, herbs and oleoresins. These can be used in commercial animals' diets to increase productivity by improving feed characteristics, enhancing the performance of the animals during production, and enhancing the quality of the byproducts produced from these animals(Windisch et al., 2008). Antibiotic growth promoters (AGPs) have been restricted in the EU, and a number of substitute chemicals are being investigated into in their stead. Due to their high concentration of pharmacologically active chemicals, photobiotic are referred to as one potential option. A huge number of in vitro and in vivo studies have confirmed a wide range of activities of photobiotic in poultry nutrition like stimulation of feed intake, antimicrobial, coccidiostatic and anthelmintic effects. Furthermore, it addresses safety concerns which may arise during application of photobiotic (Awaad et al., 2016). Additionally, over the past 20 years, the usage of photobiotic in animal feed has expanded. Studies revealed that the chances of human infections developing a resistance to antibiotics will increase if in-feed antibiotics are used excessively. The use of antibiotics as growth promoters was questioned due to bacterial resistance and antibiotic residues in animal products, which ultimately led to a prohibition on their use in feed in the majority of developed nations. Researchers and dietitians suggested photobiotic as an option. The existing documents generally point to the benefits of photobiotic on the performance of chickens. Further studies and investigations are still required to clarify many nutritional features of photobiotic due to the inconsistencies in published results. The use of particular herbs for the treatment of a given ailment as well as the abolition of the use of plant species that are potentially dangerous or toxic were made possible by numerous observations of the reactions of the animals. Currently, a wide variety of biologically active chemicals in plants that are responsible for their beneficial effects may be identified thanks to the intensive development of analytical tools. Use of plant additions, whether fresh or dried, fermented or freeze-dried, as well as water or alcohol extracts based on them, is permitted in poultry practices (Alagawany et al., 2019). These additives' mechanisms of action are not entirely understood. In addition to influencing digestion and the release of digestive enzymes, several plant extracts also have antibacterial, antiviral, and antioxidant properties (Cross et al., 2007). Therefore, they might perform a variety of tasks for the animal's body. Animals receiving feed supplemented with photobiotic show increased feed intake and secretions from the intestines (Windisch and Kroismayr, 2006). The beneficial interactions among complex active compounds found in photobiotic are likely what causes growth augmentation when they are used (Gauthier and Tarr, 2002).