Effects of direct-fed microbial (Bacillus subtilis C-3102) inclusion on tom turkey production efficiency and intestinal microbial populations

Dietary inclusions of direct-fed microbials (DFM) are becoming more common as antimicrobial use for growth promotion is no longer approved. Effects of various DFM on poultry performance have been studied; however, limited research has been conducted on the use of Bacillus subtilis C-3102 (Calsporin, Calpis America, Peachtree City, GA) in turkeys. Therefore, performance, microbial population shifts, and processing responses to Bacillus subtilis C-3102 were investigated using 720 Nicholas Select tom turkeys. Diets were formulated to be identical aside from DFM inclusion and were provided in a 6-phase feeding program. DFM diets were formulated to contain 500,000 cfu/g from d 1 to 35 and 300,000 cfu/g of the DFM from d 36 to 133. Each diet was provided to 12 replicate pens of 30 turkeys arranged in a randomized complete block design. Results from d 1 to 133 showed turkeys provided the DFM exhibited a 0.080 improvement in FCR (P < 0.001) and tended to improve BW (P = 0.099) compared to those fed the control. Fecal microbial analysis results from d 132 indicated that the ratio of Lactobacillus spp. to total anaerobes of DFM fed birds increased by 13.3% compared to those provided the control (P = 0.033). Interestingly, this ratio of Lactobacillus spp. to total anaerobes aligned with the BW progression for each phase of this study. However, d 134 processing results indicated birds consuming the control increased pectoralis minor and total breast yields (P = 0.022 and P = 0.010, respectively) compared to turkeys provided the DFM. These data indicated that Bacillus subtilis C-3102 improved tom turkey performance but reduced breast yield. Additional processing yield research using a larger sample size is warranted.