Using competitive exclusion, mannan-oligosaccharide and other intestinal products to control necrotic enteritis

Clinical and subclinical necrotic enteritis (NE) caused by the ubiquitous bacteria Clostridium perfringens can have a significant economic impact in broiler chickens. This impact is especially apparent when antibiotic feed additives are not used. In this study, the effectiveness of five nonantibiotic feed additives and two competitive exclusion (CE) cultures were compared using an NE challenge model. Untreated male broiler chickens housed in an environmentally controlled facility were challenged with C. perfringens and had high mortality, gross intestinal lesions, poor feed utilization, and reduced body weights. Broilers treated with a defined lactic acid bacterial CE culture at 1 d and fed a diet containing 2 g/ton of mannan-oligosaccharide had the lowest mortality from necrotic enteritis. The feed efficiency of this combined treatment was similar to that of broilers fed a diet containing 50 g/ton of bacitracin methylene disalicylate. The treatment in which broilers were given an undefined CE or the mannan-oligosaccharide alone, as well as three other feed additives, did not have any significant effect on feed efficiency, mortality, or body weight over the NE challenge control birds. The findings of this study are very important in developing nutritional strategies to provide options for prevention of NE without continuously using antibiotics in feed.