Ameliorative Effect of Bacillus subtilis on Growth Performance and Intestinal Architecture in Broiler Infected with Salmonella

SIMPLE SUMMARY: Salmonellosis is a dangerous disease in broilers that causes huge economic losses. We assumed that instead of antibiotics, a Bacillus-based probiotic may serve as an alternative to alleviate the negative effects of Salmonella infection. A control group with no feed additive, a positive control supplemented with a standard antibiotic and two groups that were supplemented with different strains and levels of Bacillus subtilis were the experimental animals of the present study. It was revealed that supplementation of probiotic bacteria induced similar results in terms of feed intake, body weight gain and feed efficiency in comparison with the group treated with antibiotics. In addition, the dimensions of intestinal villi were also improved in the probiotic-treated birds. As concluded from the results of the present study, probiotic bacteria could be used as an alternative to antibiotics against Salmonella in broilers. ABSTRACT: A total of 600 day-old broiler chicks (Ross 308) confirmed for the absence of Salmonella were randomly allocated to five treatments each with 10 replicates: negative control (basal diet only); positive control (basal diet) + infected with Salmonella; T1, Salmonella infected + avilamycin; T2, Salmonella infected + Bacillus subtilis (ATCC PTA-6737; 2 × 10(7) CFU/g) and T3, Salmonella infected + B. subtilis (DSM 172999; 1.2 × 10(6) CFU/g). The results revealed that feed intake (FI) and body weight (BW) were significantly (p < 0.01) lower in T1 compared to T2. The feed conversion ratio (FCR) was significantly (p < 0.01) lower in T2 and T3 compared to other treatments. Similarly, the performance efficiency factor (PEF) was also significantly (p < 0.01) higher in T2 and T3 compared to positive control. Villus height was significantly (p < 0.01) higher in T2 compared to all other treatments. However, villus width and surface area were significantly (p < 0.01) higher in T1. In conclusion, dietary supplementation with B. subtilis improved growth and intestinal health by reversing the negative effects of Salmonellosis.