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This study is aimed to assess the effects of pomegranate seed oil (PSO) supplementation on growth performance, some hematological, biochemical and immunological parameters, and disease resistance against Yersinia ruckeri in cultured rainbow trout Oncorhynchus mykiss (Walbaum, 1792). 240 fish in total were randomly assigned into four triplicate groups (20 fish/per aquarium) corresponding to four dietary treatments: control (PSO0; no addition of PSO), 0.5% (PSO5), 1.00% (PSO10), and 2.00% (PSO20) of PSO, respectively. After the 60 day-feeding trial, fish blood samples were collected and compared. Statistical analysis (one-way ANOVA) showed a significant (P < 0.05) effect of PSO on red blood cell count, hemoglobin concentration, mean corpuscular volume, mean corpuscular hemoglobin concentration, cholesterol, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase parameters in PSO5 and PSO10 with regard to control. Moreover, a pronounced (P < 0.05) increased in weight gain, growth and feed conversion was found in fish fed with PSO supplemented diets. After the feeding trial, fish were challenged with Y. ruckeri and survival recorded for 20 days. Cumulative survival was 45.10% in fish fed with the control diet, whereas in fish fed with PSO5, PSO10, and PSO20 supplemented diets, survival was 58.82, 56.86, and 56.86%, respectively. In conclusion, dietary administration of PSO induced a reduction in mortality of rainbow trout infected with Y. ruckeri, intercalary significant differences occurred on growth performance and some blood values among treated groups. These positive effects of PSO could be considered for new applications in aquaculture.

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The authors studied the effect of pepper (capsicum sp.) oil on the growth performance and 21 blood parameters in rainbow trout fed. pepper oil was added to rainbow trout feeds at the rates 22 of HPO 0‰ (0 mg/kg) (control), HPO 1‰ (1 mg/kg), HPO 2‰ (2 mg/kg), HPO 4‰ (4 mg/kg) and 23 HPO 6‰ (6 mg/kg), and the fish were fed with experimental feeds for 60 days. The group fed with 24 HPO 4‰ showed the highest percentage growth rate and the lowest feed conversion rate. Our 25 results showed the significant differences serum biochemical parameters, a decrease of serum liver 26 enzymes, glucose, cholesterol and triglyceride levels and an increase of total protein and albumin 27 levels compared with the control. The use of HPO 1‰ in rainbow trout showed a positively affects 28 the growth performance, haematological and serum biochemical parameters.

In this research the effects of oat Avena sativa extract on the non-specific immune system of common carp (Cyprinus carpio) was examined. For this purpose, the fishes (average weight 9.91 ± 1.52 g) were fed with 5 g kg À1 , 10 g kg À1 and 20 g kg À1 oat extract supplemented diets for 60 days. Following 60 days of feeding, the fishes were injected with Aeromonas hydrophila and mortalities were recorded. Lysozyme and myeloperoxidase activity, improved in all groups that received feed supplemented with oat extract. Serum glucose and cholesterol decreased while total protein and albumin in fish increased with the use of the diet supplement with oat extract. Haemoglobin (Hb), mean cell hemoglobin (MCH) and mean cell haemoglobin concentration (MCHC) increased with diet supplemented with oat extract. Oat extract at the concentration of 10 g kg À1 showed significantly higher relative percentage survival (67%) when compared with the control against A. hydrophila injection. Also the dietary supplementation with oat extract caused a significant increase in growth parameters (final weight (FW), weight gain (WG), specific growth rate (SGR) and feed conversion ratio (FCR), when compared to non-supplemented control basal diet. The results suggest that A. sativa extract can be used as a feed supplement to enhance fish immune response and disease resistance against A. hydrophila.

The aim of the present study was to evaluate the effects of essential oil extracted from bergamot (Citrus bergamia) peel on growth performance and health status of European sea bass juveniles (5.10 + 0.05 g). Test diets supplemented with 0.0%, 0.5%, 1.0% and 2.0% bergamot peel oil (BPO0, BPO0.5, BPO1 and BPO2) were fed to experimental fish for 60 days. At the end of the experiment, the best growth performance was obtained in the BPO0.5 and BPO1 groups (p < .05). No significances were found for haematological parameters including red blood cell count, haematocrit and haemoglobin concentration at the end of the feeding experiment. There were significant differences between the total protein, cholesterol, alkaline phosphatase and glutamic oxaloacetic transaminase (p < .05) between the BPO0.5 and BPO1 supplemented groups and the control group with no BPO addition. The addition of BPO showed significant differences in immune parameters such as lysozyme activity, total myeloperoxidase content, superoxide dismutase and glutathione peroxidase activity between BPO0 and BPO supplemented groups (p < .05). It might be concluded that dietary addition of 0.5%‐1% BPO could increase the growth performance and feed utilization with improved health status in sea bass juveniles.

A feeding study with Two-banded Seabream Diplodus vulgaris was conducted to determine the effects of replacement of fish oil (FO) by unrefined peanut oil (PO) on growth performance, feed utilization, body composition, fatty acid composition, and serum biochemical and hematological variables. Three isonitrogenous (35.8%) and isoenergetic (21.15 kJ/g) diets were formulated by replacing dietary FO with PO at levels of level 0% (PO 0 ), 50% (PO 50 ), or 100% (PO 100 ). Fish were fed twice a day until satiation for an experimental period of 8 weeks. The best growth performance was observed in fish fed with the PO 0 and PO 50 diets. A significant increase was observed in hematocrit and mean corpuscular volume levels of fish fed with PO 50 diet compared with the other groups. Hemoglobin, mean corpuscular hemoglobin, total protein, albumin, and globulin were not affected by dietary PO treatment and did not differ among experimental groups. The glucose level was highest in the PO 100 group. Triglyceride and cholesterol levels were lower in fish fed diets with PO inclusions than in those fed the control diet. The fatty acid composition of fish was significantly affected by the experimental diets. Glutamic oxaloacetic transaminase, glutamic pyruvictransaminase, lactate dehydrogenase, and alkaline phosphatase were not affected by dietary PO treatment. The n-3:n-6 ratio in fish fed the PO 0 diet was also higher than in fish fed the PO-supplemented diets. The results of the present study showed that FO could be substituted by PO up to 50% in Two-banded Seabream diets without any negative effect on growth performance or serum biochemical and hematological features.The marine aquaculture industry in the Mediterranean region is mainly concentrated on two fish species, namely the Gilthead Seabream Sparus aurata and European Seabass Dicentrarchus