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.

An experiment was conducted from 1 to 42 day post hatching to determine the effects of a microbial phytase (Natuphos) and glycanase preparations with predominantly xylanase and β-glucanase (Feedzyme) on the performance, serum mineral levels and antibody titer against newcastle disease, of broilers fed nutritionally marginal diets. A completely randomized experimental design was used, and chicks were divided into 5 treatment groups, with 4 replicates per treatment and 10 chicks per replicate. Diets were corn-wheat-soybean meal based with the same nutritional specifications, differing only in the concentration of Ca and nonphytate P (Ca-nPP). Treatments were: (1) diet with the energy of 2900 kcal/kg and 0.63% Ca and 0.28% available P, without enzyme (CTL+);T2) diet with the energy of 2900 kcal/kg and 0.63% Ca and 0.28% available P, without enzyme (CTL−); 3, 4 and 5) diet with the energy of 2900 kcal/kg and lower level of Ca and P (experimental group 2) respectively comprising 600,800,1000 phytase unit/kg of diet from Natuphous and 42,70,98 Xylanase unit/kg and 60,100,140 β-glucanase unit/kg of diet from feedzyme. Antibody titers against Newcastle disease were increased by incremental phytase and xylanase addition in experiments. These finding indicates that broilers consuming a ME, Ca, P-deficient corn-soybean meal-wheat diet can achieve maximum humoral immunity when phytase, xylanase and β-glucanase is supplemented to 1000, 98 and140 unit/kg diet. Performances of chicks fed with low-Ca-nPP diets plus phytase, xylanase and glucanase were comparable to those obtained with the low-Ca-nPP and adequate-Ca-nPP diets. Enzymes supplementation increased plasma Ca level (P > 0.05) but had no significant effect on plasma P level.