Efficacy of mannanoligosaccharides and humate on immune response to Avian Influenza (H9) disease vaccination in broiler chickens.

The effect of mannanoligosaccharides (MOS) and Humate (HU) in broiler diets on antibody titers against Avian Influenza virus (AIV) was evaluated. A completely randomized experimental design was used, and chicks were divided into 8 treatment groups, with 4 replicates per treatment and 10 chicks per replicate. Treatments were: 1) negative control group (CTL-), neither vaccinated against AIV nor given additives; 2) positive control (CTL+) or broilers were vaccinated against AIV + 0 additives; 3,4 and 5) CTL+ plus diet supplemented with 0.1, 0.2 and 0.3% HU, respectively; 6,7 and 8) CTL+ plus diet supplemented with 0.1, 0.2 and 0.3% MOS, respectively. For antibody analyses, blood samples were weekly collected by wing veins and the titers of antibody against AIV were measured by haemagglutination-inhibition test (HI). Compared to the positive control, the antibody titers against AIV were determined significantly lower in negative control group from 28 to 42 days of age. The inclusion of MOS resulted in increased antibody titers against AIV in the fourth, fifth and sixth weeks of age. MOS was effective in stimulating the humoral immune responses against AIV vaccine viruses. This study demonstrated an increase in the antibody titers in broilers fed diets containing 0.3% HU. In general, results of this study demonstrated that MOS proved to be much more effective on antibody production against AIV in broiler chicks than HU. Immune function could be modified with dietary HU and MOS supplementation.