Comparison of alternatives to in-feed antimicrobials for the prevention of clinical necrotic enteritis

Aims: The capacity for Lactobacillus johnsonii and an organic acid (OA) blend to prevent Clostridium perfringens-induced clinical necrotic enteritis (NE) in chickens was studied. Methods and Results: Cobb 500 birds were allocated into six groups (n = 25 birds ⁄ pen, eight pens ⁄ treatment); Unchallenged, Challenged, Antimicrobial (zinc bacitracin (ZnB) ⁄ monensin), OA, probiotic Lact. johnsonii and probiotic sham (Phosphate–buffered saline). All birds were challenged with Eimeria spp. and Cl. perfringens except for unchallenged controls. Birds fed antimicrobials were protected from NE development as indicated by maintenance of body weight, low mortality and clostridium levels, and decreased intestinal macroscopic lesion scores compared to challenged controls (P < 0Æ05). Lactobacillus johnsonii-fed birds had reduced lesion scores, whilst OA-fed birds had decreased Cl. perfringens levels. Both Lact. johnsonii and OA-fed birds had improved feed efficiency between days 0 and 28 compared to challenged controls; however, mortality and body weights were not improved by either treatment. Microbial profiling indicated that the challenge procedure significantly altered the jejunal microbiota. The microbiota of antimicrobial-fed birds was significantly different from all other groups. Conclusions: Whilst Lact. johnsonii and OA altered specific intestinal parameters, significant protection against NE was not observed. Significance and Impact of the Study: Lactobacillus johnsonii and OA did not prevent NE; however, some improvements were evident. Other related treatments, or combinations of these two treatments, may provide greater protection.M.S. Geier, L.L. Mikkelsen, V.A. Torok, G.E. Allison, C.G. Olnood, M. Boulianne, R.J. Hughes and M. Choc

Effects of novel feed additives on gut health and overall performance in birds challenged with Clostridium Perfringens

The capacity for Lactobacillus johnsonii and an organic acid (OA) blend to prevent necrotic enteritis (NE) was studied. Additionally, we evaluated the influence of Clostridium perfringens challenge, zinc bacitracin (ZnB), L. johnsonii and OA on the intestinal microbiota. Cobb 500 birds were allocated into six groups; unchallenged (Control), challenged (Cp), zinc bacitracin (ZnB), organic acid (OA), L. johnsonii, and vehicle (n = 25 birds/pen, 8 pens/treatment). All birds were challenged with C. perfringens except for the Control group. Only birds fed ZnB were protected from NE as indicated by maintenance of body weight, low mortality and clostridia levels, and decreased intestinal macroscopic lesion score compared to Cp-challenged controls. L. johnsonii-fed birds had reduced lesion scores whilst OA-fed birds had reduced clostridia levels. Both L. johnsonii and OA-fed birds had improved feed conversion ratios; however, mortality and body weights were not improved by either treatment. Microbial profiling indicated that C. perfringens significantly altered the jejunal microbiota. The microbiota of ZnB-fed birds was different to all other treatments. Whilst OA and L. johnsonii altered some intestinal parameters, no protection against NE was observed. The search for alternatives to antibiotics is important for the poultry industry. Knowledge of the mechanisms involved in ZnB-mediated protection may lead to the identification of compounds (or combinations) that promote a similar intestinal environment.M. S. Geier, L. L. Mikkelsen, V. A. Torok, G. E. Allison, C. Olnood, A. Setia, M. Choct, M. Boulianne and R. J. Hughe

Comparison of alternatives to in-feed antimicrobials for the prevention of clinical necrotic enteritis

Aims:  The capacity for 'Lactobacillus johnsonii' and an organic acid (OA) blend to prevent 'Clostridium perfringens'-induced clinical necrotic enteritis (NE) in chickens was studied. Methods and Results:  Cobb 500 birds were allocated into six groups (n = 25 birds/pen, eight pens/treatment); Unchallenged, Challenged, Antimicrobial (zinc bacitracin (ZnB)/monensin), OA, probiotic 'Lact. johnsonii' and probiotic sham (Phosphate–buffered saline). All birds were challenged with 'Eimeria' spp. and 'Cl. perfringens' except for unchallenged controls. Birds fed antimicrobials were protected from NE development as indicated by maintenance of body weight, low mortality and clostridium levels, and decreased intestinal macroscopic lesion scores compared to challenged controls (

Effects of novel feed additives on gut health and overall performance in birds challenged with 'Clostridium perfringens'

The capacity for 'Lactobacillus johnsonii' and an organic acid (OA) blend to prevent necrotic enteritis (NE) was studied. Additionally, we evaluated the influence of 'Clostridium perfringens' challenge, zinc bacitracin (ZnB), 'L. johnsonii' and OA on the intestinal microbiota. Cobb 500 birds were allocated into six groups; unchallenged (Control), challenged (Cp), zinc bacitracin (ZnB), organic acid (OA), 'L. johnsonii', and vehicle (n = 25 birds/pen, 8 pens/treatment). All birds were challenged with 'C. perfringens' except for the Control group. Only birds fed ZnB were protected from NE as indicated by maintenance of body weight, low mortality and clostridia levels, and decreased intestinal macroscopic lesion score compared to Cp-challenged controls. 'L. johnsonii'-fed birds had reduced lesion scores whilst OA-fed birds had reduced clostridia levels. Both 'L. johnsonii' and OA-fed birds had improved feed conversion ratios; however, mortality and body weights were not improved by either treatment. Microbial profiling indicated that 'C. perfringens' significantly altered the jejunal microbiota. The microbiota of ZnB-fed birds was different to all other treatments. Whilst OA and 'L. johnsonii' altered some intestinal parameters, no protection against NE was observed. The search for alternatives to antibiotics is important for the poultry industry. Knowledge of the mechanisms involved in ZnB-mediated protection may lead to the identification of compounds (or combinations) that promote a similar intestinal environment