The modulating effect of β-1,3/1,6-glucan supplementation in the diet on performance and immunological responses of broiler chickens

The object of this trial was to investigate the effect of dietary beta-1,3/1,6-glucan supplementation on the performance and immunological response of broiler chickens. Two hundred and forty 1-day old male broilers (39 +/- 1 g) were separated into six treatments which were given six different feeds containing 0 (control), 25, 50, 75, 100 and 125 mg/kg dietary beta-1,3/1,6-glucan supplementation. On days 21 and 42, body weight gain, feed consumption and feed conversation rate were recorded as measures of growth performance. The levels of key cytokines in the immuno-regulating pathway: interleukin-1 (IL-1), interleukin-2 (IL-2), interferon gamma (IFN-gamma), tumor necrosis factor alpha (TNF-alpha), and the concentrations of signal molecules: peripheral blood plasma globulin, serum Immunoglobulin G (IgG) and intestinal secretary Immunoglobulin A (slgA), were measured as indices of the immune response to determine suitable levels of dietary beta-1,3/1,6-glucan supplementation. The results indicated that performance was elevated quadratically with dietary beta-1,3/1,6-glucan supplementation. Maximal growth performance and an enhanced immunological response were obtained at a supplemented level of 50 mg/kg.