Supplementation of oligosaccharide-based polymer enhanced growth and disease resistance of weaned pigs by modulating intestinal integrity and systemic immunity

BACKGROUND: There is a great demand for antibiotic alternatives to maintain animal health and productivity. The objective of this experiment was to determine the efficacy of dietary supplementation of a blood group A6 type 1 antigen oligosaccharides-based polymer (Coligo) on growth performance, diarrhea severity, intestinal health, and systemic immunity of weaned pigs experimentally infected with an enterotoxigenic Escherichia coli (ETEC), when compared with antibiotics. RESULTS: Pigs in antibiotic carbadox or Coligo treatment groups had greater (P < 0.05) body weight on d 5 or d 11 post-inoculation (PI) than pigs in the control group, respectively. Supplementation of antibiotics or Coligo enhanced (P < 0.05) feed efficiency from d 0 to 5 PI and reduced (P < 0.05) frequency of diarrhea throughout the experiment, compared with pigs in the control group. Supplementation of antibiotics reduced (P < 0.05) fecal β-hemolytic coliforms on d 2, 5, and 8 PI. Pigs in antibiotics or Coligo groups had reduced (P < 0.05) neutrophil counts and serum haptoglobin concentration compared to pigs in the control group on d 2 and 5 PI. Pigs in Coligo had reduced (P < 0.05) total coliforms in mesenteric lymph nodes on d 5 and 11 PI, whereas pigs in antibiotics or Coligo groups had reduced (P < 0.05) total coliforms in spleen on d 11 PI compared with pigs in the control group. On d 5 PI, pigs in the Coligo group had greater (P < 0.05) gene expression of ZO1 in jejunal mucosa, but less (P < 0.05) mRNA expression of IL1B, IL6, and TNF in ileal mucosa, in comparison with pigs in the control group. Supplementation of antibiotics enhanced (P < 0.05) the gene expression of OCLN in jejunal mucosa but decreased (P < 0.05) IL1B and IL6 gene expression in ileal mucosa, compared with the control. On d 11 PI, supplementation of antibiotics or Coligo up-regulated (P < 0.05) gene expression of CLDN1 in jejunal mucosa, but Coligo reduced (P < 0.05) IL6 gene expression in ileal mucosa compared to pigs in the control group. CONCLUSIONS: Supplementation of Coligo improved growth performance, alleviated diarrhea severity, and enhanced gut health in weaned pigs infected with ETEC F18 in a manner similar to in-feed antibiotics. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40104-021-00655-2.