Effect of Bacillus-based probiotics on improving the intestinal health and performance under enteritis challenge in broiler chickens

This study investigated the effects of Bacillus-based probiotics on performance and intestinal health in broiler challenged with Clostridium perfringens-induced necrotic enteritis. One-day-old Arbor Acre (n=480) were randomly assigned to four treatments with 10 cages of 12 birds. Dietary treatments were; basal diet negative control (NC), with no probiotics nor antibiotics formulated to contain 2,930 and 3,060 kcal/kg with 24.1 and 16.0% CP, for starter and finisher diet, respectively; basal diet + enramycin (5 mg/kg), an antibiotic growth promoter (AGP); basal diet + Bacillus subtilis DSM 32315 (1 × 10⁶ CFU per g of feed, BS) and basal diet + Bacillus licheniformis (1 × 10⁶ CFU per g of feed, BL). Growth performance, intestinal morphology, intestinal lesion scores and short-chain fatty acids (SCFAs) were assessed. Average daily weight gain was significantly (P=0.01) higher in BS and AGP-fed groups. Feed conversion ratio was lowest in BS fed group compared to other dietary treatments (P=0.06). Similarly, mortality was lower in all probiotic fed groups compared to AGP-fed group (P=0.001). Intestinal lesion scores was not different among dietary treatments at d 21 (P=0.10) while it was significantly lower (P = 0.03) in birds fed AGP at d 35. In the duodenum and jejunum villus height to crypt depth (VH: CD) was higher compared with NC and BS. Probiotics-fed groups showed higher total SCFAs, acetic and butyric acid concentrations at d21 post-challenge than other groups. The present study indicated that Bacillus-based probiotics can ameliorate the enteritis conditions caused due to Clostridium perfringens challenge and the effects are similar to AGP-fed birds.

Keywords: Antibiotic growth promoter, Bacillus licheniformis, Bacillus subtilis, broiler, necrotic enteritis.