Necrotic enteritis in broiler chickens: disease characteristics and prevention using organic antibiotic alternatives-a comprehensive review

In line with the substantial increase in the broiler industry worldwide, Clostridium perfringens- induced necrotic enteritis (NE) became a continuous challenge leading to high economic losses, especially after banning antimicrobial growth promoters in feeds by many countries. The disease is distributed worldwide in either clinical or subclinical form, causing a reduction in body weight or body weight gain and the feed conversion ratio, impairing the European Broiler Index or European Production Efficiency Factor. There are several predisposing factors in the development of NE. Clinical signs varied from inapparent signs in case of subclinical infection (clostridiosis) to obvious enteric signs (morbidity), followed by an increase in mortality level (clostridiosis or clinical infection). Clinical and laboratory diagnoses are based on case history, clinical signs, gross and histopathological lesions, pathogenic agent identification, serological testing, and molecular identification. Drinking water treatment is the most common route for the administration of several antibiotics, such as penicillin, bacitracin, and lincomycin. Strict hygienic management practices in the farm, careful selection of feed ingredients for ration formulation, and use of alternative antibiotic feed additives are all important in maintaining broiler efficiency and help increase the profitability of broiler production. The current review highlights NE caused by C. perfringens and explains the advances in the understanding of C. perfringens virulence factors involved in the pathogenesis of NE with special emphasis on the use of available antibiotic alternatives such as herbal extracts and essential oils as well as vaccines for the control and prevention of NE in broiler chickens.