Current use of prebiotic as indigestible feed additive improves health statues of host, instead of drug
and chemical material in aquaculture. The aim of this experiment was to investigate the effect of
2g.kg-1 prebiotic immunogene on hematological, biochemical and some serum enzymes parameter of
rainbow trout after 7 weeks feeding. Hundred and twenty rainbow trout (81.65 ± 1.49 g) After
checking the health status and acclimatized to laboratory condition for 10 days, they were equally
stocked in six fiberglass tanks (1000 L) assigned to two levels (0 and 2 g kg-1) of Immunogen
(commercial prebiotic, ICC Co; USA) with three replicates. During the experimental trial (7 weeks)
fish were hand-fed (2% of BW) twice daily (09:00 and 17:00). At the end of trial the blood was
collected using a hypodermic syringe from the caudal blood vessels and was used to evaluate the
hematological and biochemical parameter. The results of this experiment indicated that some
hematological parameter such as RBC, Hb, MCH, MCV and MCHC were not affected by immunogen
(p>0.05), but the Hct and WBC were increased in rainbow trout immunogen (P<0.05).Considering
serum biochemical parameter it was observed that in the group fed with prebiotic immunogen
increased the level of glucose (P<0.05), Although the level of triglyceride and serum total protein
were not affected, but the level of serum cholesterol was increased in group fed with prebiotic
immunogen (P>0.05). The results indicated that administration of immunogen no effect on ALT, AST,
LDH and ALP levels. These results indicate that fish blood parameters and serum biochemical profiles
could be affected by immunogen, which should be taken into account in future studies.