bacitracin-methylenedisalicylic-acid and Necrosis

The efficacy of bacitracin methylene disalicylate (BMD) in the management of necrotic enteritis (NE) when fed in combination with narasin was investigated in a floor-pen study of 2,000 broiler chickens using a Clostridium perfringens inoculum challenge model. Treatments consisted of 1) nonchallenged-nonmedicated; 2) challenged-nonmedicated; 3) challenged-narasin (70 ppm); 4) challenged-BMD (55 ppm); 5) challenged-narasin (70 ppm) + BMD (55 ppm). Medication was provided in the feed from Day 0 to trial termination on Day 41. C. perfringens challenge occurred from Day 14 to 16. BMD and narasin, fed alone and in combination, reduced (P < 0.05) mortality due to NE when compared to challenged-nonmedicated birds. NE lesion scores (Days 0 through 41) were lower among birds fed BMD and narasin, alone and in combination, compared to challenged-nonmedicated birds. Improvements in NE mortality and NE lesion scores were greatest for the BMD + narasin-medicated birds, followed by the BMD-alone, and then narasin-alone treated birds. BMD and narasin, alone and in combination, provided improvements (P < 0.05) in average daily gains over the entire study (Days 0 to 41). The results of this study demonstrate the effectiveness of BMD and narasin in the management of NE in broiler chickens.

Topics: Animals; Anti-Bacterial Agents; Bacitracin; Chickens; Clostridium Infections; Clostridium perfringens; Enteritis; Male; Necrosis; Poultry Diseases; Pyrans; Salicylates; Weight Gain

The effect of dietary inclusion of Bacillus subtilis DSM 32315 on the intestinal health and growth performance of Cobb 500 male broilers subjected to a Clostridium perfringens-induced necrotic enteritis (NE) challenge was determined in 2 experiments. In experiment 1, chicks were randomly assigned to 4 treatments of 10 replicate/treatment. In experiment 2, chicks were randomly assigned to 4 treatments of 12 replicates/treatment. The experimental treatments were non-infected, non-supplemented control, infected, non-supplemented control (IC), infected + Bacillus subtilis DSM 32315 (B. subtilis DSM 32315), infected + bacitracin methylene disalicylate (BMD). In both experiments, NE was induced by oral inoculation of toxin producing C. perfringens on 3 consecutive days between 17 and 20 D of age, following exposure of birds to pre-disposing conditions. At day 28 (experiment 1), broilers fed diets with B. subtilis DSM 32315 exhibited a significantly higher body weight, lower mortality, and intestinal NE lesion score, compared to the IC treatment. At day 42 (experiment 2), B. subtilis DSM 32315 supplementation significantly improved BW, feed conversion ratio, production efficiency factor, NE lesion score, and mortality, compared to IC treatment. The effect of B. subtilis DSM 32315 on intestinal integrity of NE challenged chickens was evaluated with histomorphometry. A significantly shallower crypt depth and higher villus height to crypt depth ratio were observed in the mid-intestine of birds belonging to the B. subtilis DSM 32315 group, compared to the IC group. Furthermore, B. subtilis DSM 32315 supplementation significantly reduced the enteritis index associated with NE. In both experiments, the effect of B. subtilis DSM 32315 on the phenotypic measurements of NE and performance was comparable to the effect observed with BMD supplementation. In conclusion, supplementation of the direct fed microbial strain B. subtilis DSM 32315 can ameliorate the pathology and performance detriments associated with NE.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Bacillus subtilis; Bacitracin; Chickens; Clostridium Infections; Clostridium perfringens; Diet; Enteritis; Intestines; Male; Necrosis; Poultry Diseases; Probiotics; Salicylates