Animal health and growth performance are affected by many factors such as diet, stress, antibiotics and modern husbandry practices. The gastro-intestinal microflora of healthy birds would be maintained stable by using antibiotics in preventive dosages. However, it is also argued that antibiotics may have indirect adverse side effects with implications for human health through consumption of food animal origin. Increased bacterial resistance to antibiotics in humans has caused an increased public and governmental interest for eliminating sub-therapeutic use of some antibiotics in livestock. To decrease the use of antibiotics, the use of probiotics may be considered as one of alternative approaches to replace chemical additives by lactic acid bacteria. These bacteria have been consumed in fermented foods and feeds for several centuries without any obvious adverse effects .