Effect of Bacillus subtilis C-3102 spores as a probiotic feed supplement on growth performance, noxious gas emission, and intestinal microflora in broilers

Bacillus subtilis C-3102 has been used as a direct-fed microbial or probiotic product since 1986 to improve production performance in broilers worldwide. This study was conducted to determine and confirm the effect of B. subtilis C-3102 spore supplementation to feed on growth performance, nutrient digestibility, carcass quality, blood profiles, noxious gas emission, and intestinal and excreta microflora in broilers. A total of 816 one-day-old male Ross 308 broilers (46.06 +/- 0.67 g) were used in a 5-wk study with Calsporin, B. subtilis final product (1.0 x 10(9) cfu/g of B. subtilis). Broilers were randomly allotted to 1 of 3 dietary treatments consisting of 16 replicate cages with 17 broilers each: I) CON (control, basal diet), II) BS300 (CON + 300 mg of B. subtilis/kg of feed), and III) BS600 (CON + 600 mg of B. subtilis/kg of feed). Regarding probiotic effect, B. subtilis significantly increased Lactobacillus counts in the cecum, ileal, and excreta, and reduced Escherichia coli counts in the cecum and excreta, compared with CON. In addition, supplementation also tended to reduce Clostridium perfringens counts in the large intestine and excreta, while linearly reducing Salmonella counts in the cecum, ileal, large intestine, and excreta, compared with CON. Regarding growth performance, B. subtilis enhanced ADG in the starter and overall experimental periods, without any effects on feed intake compared with CON. Consequently, feed conversion ratio in the grower-finisher and overall experimental periods decreased significantly. The inclusion of B. subtilis improved the digestibility of DM and gross energy, as well as reducing ammonia emission, compared with CON. No significant difference in breast muscle color, water holding capacity, and drip loss, and relative organ weights, as well as in white blood cells, red blood cells, lymphocyte counts, and IgG amount, were observed. Overall, B. subtilis C-1302 is capable of providing a probiotic effect leading to improved growth performance and feed efficiency, due to the manipulation of intestinal microflora, with minimal side effects in broilers.