Efficacy of probiotics B. subtilis RX7 and B. methylotrophicus C14 strains as an alternative to antibiotics in weaned pigs

Abstract Text: After weaning, piglets face environmental and nutritional challenges due to which the morphology and functions of gastrointestinal tract are remarkably impaired. This may be due to alteration in the microbial balance in the gastrointestinal tract favoring the colonization of pathogens such as Salmonella and E.coli. Probiotic supplementation may play a positive role in improving the health status of weaning pigs.  Thus, an experiment was conducted with a total of 60 pigs by randomly allotting them to one of three experimental diets according to their initial BW and sex in a 42-d experiment to evaluate the efficacy of probiotics on the performance, digestibility, blood profiles, and fecal microflora. Each treatment consisted of 4 replicate pens with 5 pigs (3 barrows and 2 gilts) per pen. Dietary treatments consisted of:  CON; corn soybean meal based basal diet (without antibiotics and probiotics), T1; basal diet + 0.1% of 1x10⁹cfu/g Bacillus subtilis RX7 and T2; basal diet + 0.1% of C14 1x10⁹cfu/g Bacillus methylotrophicus.  The trial period was divided into two periods: period 1 of d 1-14 post weaning, and period 2 of d 15-42 post weaning. All data were subjected to the GLM procedures of SAS and differences among treatments were separated by Tukey’s multiple range tests with a P < 0.05 indicating significance. At the end of the experiment the ADFI was reduced (P = 0.01) in T1 (646.5 g) and T2 (646.5 g) than CON (681.7 g) and co-efficient of digestibility of Energy was increased (P < 0.05) in T1 (0.844) and T2 (0.841) compared with CON (0.806) during d 14. The supplementation of probiotics led to reduction of Salmonella counts (2.41, 2.44 vs 2.63 log 10 cfu/g) in the feces during d 14 and increase in Lactobacillus counts (7.46, 7.48 vs 7.03 log 10 cfu/g)) during d 42. There were no significant differences in blood profiles of pigs treated with probiotic. In conclusion, probiotic supplementation reduced feed intake, increased energy digestibility and Lactobacillus counts and reduced Salmonella counts in weaning pigs.

Keywords: B. subtilis, B. methylotrophicus, Salmonella Typhimurium