In this study various health status, growth and biochemical parameters following use of oregano oil ( BiorganoTM 10%Thomson Biochorporation, China ) and blend of Bacillus subtilis ( QZ-TossMR , containing 2 B cfu/ kg -QB Lab. USA) .
Six groups, in each group has 20 O.niloticus were kept in 3x4m concrete tank . Namely, group one as control, group 2 fed regular diet ( 30% protein) and QZ-Toss was added to the pond spring water , group 3 fish fed diet containing 250gm/ton Biorganoand QZ- Toss , group 4 fish as in group 3 plus addition of QZ-Toss , group 5 fish fed diet containing 500 gm/ton Bioorgano and group 6 as in group 5 plus addition of QZ-Toss.
The time of experiment was 30 days in which QZ-Toss was added in first and second weeks 2gm/m3 and one gm/m3 third and fourth weeks.
At the end of experiment, ammonia was measured in each pond water, total growth weight was measured and blood was collected for serum separation from each fish. Kidney and liver function enzymes were evaluated as well as some antioxidants levels were measured.
Tissue samples from liver, kidney, spleen and intestine were collected and use for expression of immune-related genes and histopathological changes.
The results revealed decreased in ammonia levels and increase in body weight in all groups compared to the control. Moreover, liver and kidney function enzymes were showed no significant difference compared to control. The both concentration of Bioorgano enhanced oxidative stress reduction but did not affect GPx antioxidant levels.
Both use of Bioorgano and QZ-Toss significantly induced the expression of cytokines and immune-related genes. Namely, IL-1B, TLR-7, MX, TL8 and TCR.