The objective of the current study was to evaluate the effects of a commercial prebiotic (Hemicell^®)
as a growth promoter on growth performance, intestinal morphometry and IL-1 and IL-2 gene
expression in spleen of Japanese quail. A total number of 360 one-day-old Japanese quail chicks
were randomly allocated into 4 equal groups. Group 1(control group) fed on the basal diet that not
supplemented with prebiotic, group 2 fed on basal diet supplemented with 0.5 g Hemicell/kg diet,
group 3 fed on basal diet supplemented with 1.0 g Hemicell/kg diet and group 4 fed on basal diet
supplemented with 1.5 g Hemicell/kg diet. To evaluate growth parameters, 30 birds from each
group were weighed weekly for six successive weeks. Spleen tissues were collected at 21 and 42
days after supplementation from all quail groups (control and experimental groups). At the end of
the experiment, the results of the current study revealed that, feeding Japanese quails on diet
supplemented with Hemicell resulted in improved growth and growth performance as indicated by
increased body weight and weight gain. Also, intestinal morphometry revealed an increase in height
and base width of intestinal villi in a dose dependent manner. Moreover, Real time PCR indicated
upregulation of the IL-1 and IL-2 genes expression in a dose and time dependent manner. In
conclusion, addition of β-mannanase in Japanese quail diets would have beneficial effects on
performance and immunity in birds.