Abstract:

In order to study the effects of dietaryβ-mannanase on the growth performance and immunity function of AA+ chicken, one hundred and eighty one-day-old AA+ chicken were randomly divided into control group and treatment group, each group had 3 replicates and 30 AA+ chicken in each replicate. Control group was fed with basal diet，treatment group was fed with basal diet supplemented 0.04% β-mannanase. The experiment period is 42 days. The results showed that β-mannanase could increase significantly average daily gain，and feed conversion rate(FCR). there were significant differences between treatment and control groups (P<0.05) in 1-21d and 1-42d; enhance significantly the levels of immunoglobulin M (IgM), IgA, and IgG in viremic blood(P<0.05). Immune organ indexes, antibody level against ND and T lymphocyte transformation rate had different degrees of improvement，but no significant difference(P>0.05) between control group and treatment group. The results indicated that β-mannanase could improve respectively the growth performance. and immunity function of AA+ chicken.