Effect of Galacto-mannan-oligosaccharides or Chitosan Supplementation on Cytoimmunity and Humoral Immunity in Early-weaned Piglets

Immunomodulatory feed additives might offer alternatives to antimicrobial growth promoters in pig production. This experiment was designed to determine the effects of dietary galacto-mannan-oligosaccharide (GMOS) and chitosan oligosaccharide (COS) supplementation on the immune response in early-weaned piglets. Forty 15-day-old piglets (Duroc$\times$Landrace$\times$Yorkshire) with an average live body weight of $5.6{\pm}0.51kg$ were weaned and randomly assigned to 4 treatment groups that were fed maize-soybean meal diets containing either basal, 110 mg/kg of lincomycin, 250 mg/kg of COS or 0.2% GMOS, respectively, over a 2-week period. Another six piglets of the same age were sacrificed on the same day at the beginning of the study for sampling, in order to obtain baseline values. Interleukin (IL)-1${\beta}$gene expression in peripheral blood monocytes, jejunal mucosa and lymph nodes, as well as serum levels of IL-1${\beta}$ IL-2 and IL-6, IgA, IgG, and IgM, were evaluated for 5 pigs from each group at 15 and 28 days of age. The results indicate that weaning stress resulted in decreases in serum antibody and cytokine levels. Dietary supplementation with GMOS or COS enhanced (p<0.05) IL-1${\beta}$gene expression in jejunal mucosa and lymph nodes, as well as serum levels of IL-1${\beta}$ IL-2, IL-6, IgA, IgG and IgM compared to supplementation with lincomycin. These findings suggest that GMOS or COS may enhance the cell-mediated immune response in early-weaned piglets by modulating the production of cytokines and antibodies, which shows that GMOS or COS have different effects than the antibiotic on animal growth and health.