Effects of Supplementation of Bacillus subtilis LS 1–2 Grown on Citrus-juice Waste and Corn-Soybean Meal Substrate on Performance and Gut Health of Weaning Pigs

The present experiment was conducted to investigate the effects of dietary supplementation with Bacillus subtilis LS 1–2 grown on citrus-juice waste and corn-soybean meal substrate on performance and gut health of weaning pigs. A total of 240 weaning pigs (Landrace x Yorkshire x Duroc) were randomly allotted to 4 treatments, each with 4 replicates of 15 pigs. Dietary treatments included basal diet without any antimicrobial (NC; negative control) or with 150 mg/kg apramycin (PC; positive control), 0.45% B. subtilis LS 1–2 grown on corn-soybean substrate (P1) and 0.45% B. subtilis LS 1–2 grown on citrusjuice waste substrate (P2). The experimental diets were fed in a meal form for 2 phases (d 0–14, phase I and d 14–28, phase II). Overall ADG, ADFI, FCR and ATTD of DM and GE (d 14, d 28) were better (P<0.05) in pigs fed the PC, P1 and P2 diets than pigs fed the NC diet. Also, the ATTD of CP (d 14 and d 28) in pigs fed the PC and P2 diets was greater (P<0.05) than pigs fed the NC diet. At d 28, pigs fed the PC diet had lower (P<0.05) caecal total anaerobic bacteria, Clostridium spp. and coliforms than pigs fed the NC diet. In addition, pigs fed the P2 diet had lower (P<0.05) caecal coliforms than pigs fed the NC diet. Pigs fed the PC, P1 and P2 diets had greater (P<0.05) villus height and villus height: crypt depth than pigs fed the NC diet. In addition, growth performance, ATTD of nutrients, caecal microbial population and intestinal morphology of pigs fed P2 diet were not different (P>0.05) from pigs fed the PC diet. These results indicate that B. subtilis LS 1–2 inclusion at 0.30% level had beneficial effects on weaning pigs growth performance, ATTD of nutrients, caecal microflora and intestinal morphology. Additionally, citrus-juice waste can be used as substrate for growth of probiotic B. subtilis LS 1–2.