Effect of different levels of essential oils (Satureja hortensis) in diet on improvement growth, blood biochemical and immunity of Angelfish (Pterophyllum scalare Schultze, 1823).

The aim of this study was designed to analyse the effect of Savoury essential oil (Satureja hortensis) on growth performance, biochemical parameters and immunity of angelfish (Pterophyllum scalare). The angelfishes (average body weight of 5.12 ± 0.01 g) were treated with three effective dosage of Savoury essential oil 100, 200 and 400 mg/kg in three separated aquaria water with one control group for 60 days. At the end of experiment, the angelfishes treated with 400 mg/kg Satureja showed minimum Feed Conversion Ratio, maximum Specific Growth Rate and Survival Rate. There was significant difference (p < 0.05) between the treated and control fish in the serum total protein, albumin, globulin, triglyceride, cholesterol, glucose and cortisol. Maximum significant amount (p < 0.05) in immunoglobulin is found in both 200 and 400 mg/kg Savoury concentration group, while significant enhancement in serum lysozyme was only found in 200 mg/kg group. Overall, the results presented in the current study revealed that savoury is a beneficial dietary supplement to improve growth performance, stress resistance and innate immune response of angelfish and the best level of inclusion was 200 mg/kg.

The protective role of vitamin E on Oreochromis niloticus exposed to ZnONP.

The present study evaluated if ZnONPs induce oxidative stress, immunological impairment and cellular damage in tilapia (Oreochromis niloticus), as well as the possible protective effect of vitamin E. Fish were fed for ten days and five study groups were investigated: controls, two ZnONPs concentrations (1.5 and 2.5mgL-1) and 1.5 and 2.5mgL-1 of ZnONPs + vitamin E (500mgkg-1 of food). O. niloticus treated with ZnONPs, showed decreased health in comparison with the control group and the groups that combined nanoparticles and vitamin E-supplemented diet. ZnONPs caused cell impairment by increasing ALT, AST and ALP activity and generated oxidative stress by inhibiting SOD and CAT activity. Biochemical changes of these biomarkers were prevented by vitamin E, although this compound did not confer complete protection. In conclusion, ZnONPs are toxic to O. niloticus, affecting antioxidant defenses, with vitamin E acting protectively against this toxic effect.

Protective effects of the prebiotic on the immunological indicators of rainbow trout (Oncorhynchus mykiss) infected with Aeromonas hydrophila.

The aim of this study was to investigate the protective effects of dietary administration of commercial prebiotic, Immunogen, on immunological indicators, enzymatic responses and stress tolerance in juvenile (81.65 ± 1.49) rainbow trout (Oncorhynchus mykiss) following Aeromonas hydrophila infection. The first group of fish was fed with the diet containing 2 g kg(-1) Immunogen whilst the control group received the diet free of Immunogen. There were three replicates per group. After 6 weeks feeding, the control group were divided into two treatments injected with saline buffer (control), and 1.5 × 10(8) CFU A. hydrophila respectively. The fish fed with the Immunogen supplemented diet were also injected with 1.5 × 10(8) CFU A. hydrophila. Our results revealed that dietary Immunogen increased the level of white blood cell (WBC) and percentage of lymphocyte (P < 0.05), however, the level of red blood cell (RBC), Hematocrit (Hct), hemoglobin (Hb) and percent of monocyte decreased in Untreated-Challenged group but unaffected in the group fed with Immunogen (P < 0.05). The level of lysozyme, alternative complement, antiprotease activity, total protein, albumin and globulin decreased in Untreated- Challenged group compared to control group. However, there was an increase in the level of lysozyme, alternative complement, antiprotease activity, bactericidal activity, in the Treated- Challenged group compared to other groups (P < 0.05). Serum alkali phosphatase (ALT) and aspartate aminotransferase, significantly increased fallowing challenge with A. hydrophila but in the Treated-Challenged group, there was no significant difference compared to the control group (P < 0.05). Lactate dehydrogenase (LDH) level was not different between groups (P > 0.05). Serum cortisol and glucose levels were higher in the challenge group, but these levels were lower in fish under challenge that were fed Immunogen-supplemented diet in contrast to the group fed control diet. The stress responses affected by A. hydrophila challenge (P < 0.05). Serum sodium, potassium and calcium concentration decreased by A. hydrophila exposure (P < 0.05), and Immunogen showed protection effect against this change.