A new low mortality necrotic enteritis challenge model

Necrotic enteritis (NE) in broilers - caused by 'Clostridium perfringens' - is largely controlled by in-feed antibiotics in Australia. Alternatives to antibiotics are being sought by industry and must be tested under simulated outbreak conditions. An existing NE challenge model employed at UNE has demonstrated differences between NE intestinal lesion score between unmedicated challenged and unchallenged controls. However, up to 20% NE-related mortality was routinely observed in challenged groups without an antibiotic (Zn bacitracin). A different model was required to minimise mortality and improve the relevance of the data to industry. In the current study, a new NE challenge model was developed by removing a protein-fortified pre-challenge diet and replacing it with standard wheat-based starter and grower diets, formulated to broiler breed standard specifications.