One-day-old Ross 308 male broiler chicks were used to investigate the additive effect during growth of Bacillus subtilis B2A derived from soil samples on productivity, organ weight, intestinal Salmonella microflora, and breast meat quality. Five hundred seventy-six birds (46 +/- 0.5 g) were fed 3 different levels of B. subtilis B2A (1.1 x 10(4), 1.0 x 10(5), and 1.0 x 10(6) cfu), in a basal diet based on corn-soybean meal, for 28 d. In the current study, feed intake and feed conversion during 1 to 28 d showed significant improvement as dietary B. subtilis B2A increased from 1.1 x 104 to 1.0 x 10(6) cfu (linear, P < 0.05). All blood parameters, such as white blood cells, red blood cells, and lymphocyte and haptoglobin concentrations, were not influenced by B. subtilis B2A added into the diet; however, the weights of the bursa of Fabricius were significantly increased linearly in B. subtilis B2A-fed groups (P < 0.05). Bacillus subtilis B2A supplementation was associated with reduced intestinal Salmonella burden (linear and quadratic, P < 0.05). Breast meat pH and color were not affected by B. subtilis B2A, but 1 d drip loss was decreased (linear, P < 0.05). Our observations suggest that B. subtilis B2A benefits productivity and reduces Salmonella in broilers.
