Efficacy of phytase and glycanase enzymes on the performance, serum mineral levels and antibody titer against newcastle disease virus (NDV) of broilers fed nutritionally marginal diets

摘要

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.