Sebahattin Ergün

Effect of dietary Ulva and Spirulina on weight loss and body composition of rainbow trout, Oncorhynchus mykiss (Walbaum), during a starvation period.

A study was conducted to determine the effect of dietary algal supplementation on weight loss and proximate composition in rainbow trout, Oncorhynchus mykiss, during starvation. An algae-free control diet (C) and four experimental diets, including varying levels of raw Ulva meal (5% = U5; 10% = U10) and Spirulina meal (5% = S5; 10% = S10) were formulated. Fish were fed to satiation for 12 weeks and then subjected to a 3-week starvation period. Body weight, viscerosomatic index (VSI, %), hepatosomatic index (HSI, %), dress-out (DO, %) and chemical composition of carcass were analysed at the end of each starvation week. The accumulated weight loss of the fish fed dietary algae was almost 50% less than the control group (p < 0.05) after 2 and 3 weeks starvation. No significant differences in weight loss were observed among the fish fed different algal diets during the starvation period. Total body protein and ash contents remained constant in all groups throughout the starvation period. Fish in all treatments lost a significant level of total lipids and changes of liver fatty acid profiles were also observed. Results indicate that low level inclusion of algae in aquafeeds may have economical advantages in terms of reducing weight loss in fish when subjected to a short-term fasting period, that sometimes is necessary after a heavy rainfall or when fish stocks are held back to meet market demand.

Effects of garlic and ginger oils on hematological and biochemical variables of sea bass Dicentrarchus labrax.

This study was conducted to investigate the effects of garlic and ginger oils on hematological and biochemical health characteristics of sea bass Dicentrarchus labrax. Fish were exposed to garlic oil (0.01 or 0.02 mL/L), ginger oil (0.01 or 0.02 mL/L), or a combination of the two oils (each oil at a concentration of 0.005 or 0.01 mL/L) for 96 h via bath immersion. Results showed that the red blood cell count, hematocrit (%), hemoglobin (Hb) concentration (g/dL), mean corpuscular volume (μm(3)), mean corpuscular Hb (pg), and mean corpuscular Hb concentration (%) were not significantly affected by herb oil exposure. However, some changes in biochemical variables were observed. Sea bass exposed to the 0.005-mL/L garlic oil-ginger oil mixture exhibited a significant increase in serum glucose. Serum total protein and albumin levels decreased in sea bass that were exposed to a garlic oil-ginger oil mixture (0.005 or 0.01 mL/L) or to garlic oil at 0.02 mL/L. Serum globulin levels decreased and triglyceride levels increased in sea bass exposed to 0.02-mL/L garlic oil or to the 0.01-mL/L mixture. The serum lipase level decreased and the cholesterol level increased in fish that were exposed to 0.02-mL/L garlic oil. In summary, ginger oil at 0.01-0.02 mL/L can be used without negative effects, while the garlic oil or garlic oil-ginger oil mixture should be applied at a concentration below 0.005 mL/L for bath immersion of sea bass. This is the first study to examine how garlic oil and ginger oil exposure via bath immersion affects the hematological and biochemical status of sea bass.

Effect of Dietary Herbal Supplements on Some Physiological Conditions of Sea Bass Dicentrarchus labrax

This study was conducted in order to investigate the effects of dietary thyme Thymus vulgaris, rosemary Rosmarinus officinalis,and fenugreek Trigonella foenum graecum as feed additives on total liver fat levels and biometric indices of Sea Bass Dicentrarchus labrax. Four isonitrogenous (48% crude protein) and isocaloric(21 kJ/g) diets were formulated to contain 0% (control), or 1% of thyme, rosemary, or fenugreek. In a 45-d feeding trial, 12 fiberglass tanks (140 L) were each stocked with 17 fish (20.43 ± 0.03 g).Herbal supplemented diets significantly decreased the total liver fat, visceral fat index, viscerosomatic index, hepatosomatic index,and increased the spleen–somatic index and bile–somatic index(P<0.05). In conclusion, the results indicated that a dietary level of1.0% for thyme, rosemary, or fenugreek could improve some of the physiological parameters of Sea Bass. Thus, this work provides anew perspective for the use of medicinal herbs that can be added to fish feed to improve the status of fish organs. Thyme, rosemary, and fenugreek contain a number of different active components, which possibly play an important role in improving these conditions, but the mechanism by which this is achieved needs further and more detailed study.

Trans-cinnamic acid application for rainbow trout (Oncorhynchus mykiss): I. Effects on haematological, serum biochemical, non-specific immune and head kidney gene expression responses

ABSTRACT The present study investigated the effects of dietary trans‐cinnamic acid (CA) on pre‐ and post‐challenge haematological, serum biochemical, non‐specific immune and head kidney gene expression responses of rainbow trout, Oncorhynchus mykiss juveniles. In this regard, fish with an average weight of 17.01±0.05g were divided into five groups, and fed daily with an additive free basal diet (control); 250, 500, 750 or 1500mgkg−1CA for a 60‐day period. Fish were sampled every 20 days during the experiment. On days 20, 40 and 60 (the pre‐challenge period), the dietary CA especially at 250 and/or 500mgkg−1 significantly increased blood granulocyte percentage, and serum total protein, globulin, lysozyme and total immunoglobulin values. Furthermore, dietary CA increased activities of phagocytic activity, respiratory burst and potential killing, and increased the expression levels of immune related genes [serum amyloid A (SAA), interleukin 8 (IL‐8), interleukin 1, beta (IL‐1&bgr;), transforming growth factor beta (TGF‐&bgr;), tumor necrosis factor (TNF‐&agr;), and immunoglobulin T (IgT)] in the head kidney of fish fed with 250 and/or 500mgkg−1CA. Following 60 days of feeding, fish were challenged with Yersinia ruckeri and mortality was recorded for 20 days. Highest percentage survival (%) rate was found in the 250 and/or 500mgkg−1 CA‐supplemented feeding groups. During the post‐challenge period, red blood cell (RBC) count, hematocrit (%), respiratory burst activity, and total antiprotease activity increased in fish fed with feed containing 500mgkg−1 content. Moreover, markedly up‐regulated the expression of related genes (SAA, IL‐8, IL‐1&bgr;, TGF‐&bgr;, TNF‐&agr;, IFN‐&ggr; and IgM) in fish fed 250, 500 and/or 750mgkg−1CA. Therefore, feeding O. mykiss for 60 days with dietary CA at 250–500mgkg−1CA incorporation levels can be suggested as optimal to enhance the immunity and disease resistance against Y. ruckeri. HIGHLIGHTSDietary CA had several positive effects on haematological, serum biochemical and non‐specific immune responses of fish.Dietary CA orchestrated the inflammatory response by up‐regulating the SAA, IL‐8, IL−1&bgr;, TGF‐&bgr;, IFN‐&ggr;, TNF‐&agr;, IgM and IgT.CA enhanced the protection of rainbow trout against Yersinia ruckeri.

Effects of medicinal herb extracts on egg hatching of the angel fish (Pterophyllum scalare).

Bu calismada, bazi kimyasallar ve tibi bitki ozutlerinin melek baligi (Pterophyllum scalare) yumurta acilimi ve sudaki bakteri yuku uzerine etkisi incelenmistir. Bu amacla metilen mavisi 0.5 ppm ve potasyum permanganat 0.2 ve 0.4 ppm uygulanmistir. Biberiye, civanpercemi ve sumak ozutlerinin herbiri ise 1.000, 5.000 ve 10.000 ppm olarak uygulanmistir. Metilen mavisi 0.5 ppm, potasyum permanganat 0.2 ppm, biberiye 1.000, 5.000, ve 10.000 ppm ve civanpercemi 5.000 ppm uygulamalari sudaki bakteri yukunu azaltmis ve yumurta acilimini onemli oranda arttirmistir (P<0.05). Biberiye ozutunun konsantrasyonu arttikca bakteri yuku azalmis ve yumurta acilimi artmistir. Tum sumak uygulamalari bakteri yukunu azaltmis, ancak yumurta aciliminini olumsuz etkilemistir. Elde edilen bulgular yumurta acilimi icin en uygun tibbi bitki ozutunun biberiye oldugunu gostermistir. Sonuc olarak bu calismada biberiye ozutunun sentetitik kimyasallar yerine kullaniminin daha uygun ve melek baligi yumurta acilimi icin optimum biberiye ozut dozajinin 1.000 ppm oldugu bulunmustur.

Bioaccumulation of trace metals in Mediterranean mussels (Mytilus galloprovincialis) from a fish farm with copper-alloy mesh pens and potential risk assessment

ABSTRACT Concentrations of trace metals were determined in the muscle tissue, digestive gland and gills of Mediterranean mussels (Mytilus galloprovincialis) collected from different locations around an offshore copper alloy fish farm. Levels of copper (Cu), zinc (Zn), manganese (Mn) and iron (Fe) as mg/kg wet weight in the edible part of the mussels collected from distant zone (upstream Zn7.33 > Fe2.8 > Cu0.13 > Mn0.07 and downstream Zn9.9 > Fe5.67 > Cu0.18 > Mn0.17) were significantly lower (p < 0.05) than those sampled from the cage zone (bottom panel Zn22.25 > Fe13.75 > Cu2.39 > Mn0.85 and cage frame Zn17.1 > Fe8.74 > Cu1.39 > Mn0.26). Trace metal concentrations in mussels were significantly higher (p < 0.05) in the samples from the frame and bottom panel of the copper alloy mesh pen, compared to those from distant areas, namely the farm affected downstream -and non-affected upstream locations. However, the rates of target hazard quotients (THQ) for all tested trace metals from all locations in the present study were smaller than “one” (THQ < 1), indicating that the consumption of mussels grown around a cage farm with copper alloy mesh pens were within safe limits and did not exceed maximum levels suggested by the US Food and Drug Administration (USFDA) and European Union (EU) regulations for seafood consumption.

Dietary olive leaf (Olea europea L.) extract alters some immune gene expression levels and disease resistance to Yersinia ruckeri infection in rainbow trout Oncorhynchus mykiss

ABSTRACT The aim for the present study was to investigate the effects of olive leaf (Olea europea L.) extract (OLE) on the control of Yersinia ruckeri infection in rainbow (Oncorhynchus mykiss) trout and to assess the impact on the expression of immune‐related genes in the spleen and serum biochemical parameters of rainbow trout. Five experimental diets were prepared by adding 0.0%, 0.1%, 0.25%, 0.50% and 1.0% of OLE. Each diet was fed to triplicate groups of fish (mean body weight 51.22±3.04g) twice a day (at 09:00 and 17:00h) for 60 days. The dietary supplementation of OLE did not affect growth performance and feed utilization (P>0.05). Major changes due to graded levels of OLE in the diets were observed in blood biochemical parameters (P<0.05). TNF&agr;, IL1‐&bgr; and IL‐8 gene expressions were significanlty up‐regulated in OLE 0.1% group compared with others (P<0.05). Also, diet supplemented with OLE reduced mortality in rainbow trout fed with OLE 0.1% added diet. Present study suggests that OLE especially at 0.1% added feed may effectivelly enhance the serum biochemical parameters, survival rate and immune gene expression in rainbow trout. HIGHLIGHTSAn nature plant extract show enhancement on immune responce in rainbow trout.Increasing disease resistant against fish pathogen.Short term application of olive leaf extract gave a valuable result for fish farms.This study result obtained in natural enviromental condition in a trout farm.

Hazelnut meal in diets for seawater farmed rainbow trout (Oncorhynchus mykiss): effects on growth performance and body composition

Abstract A 77-day feeding trial was designed in order to assess the effect of partial or total replacement of soybean meal by hazelnut meal (HNM) on feed intake, growth performance, nutrient utilization and body composition of rainbow trout (initial mean body weight: 80.0±3.5 g) in seawater conditions. A control and three experimental diets were formulated in which soybean meal level (25.5%) in the control diet was replaced by hazelnut meal at 39.2 (HN 39), 78.4 (HN 78) and 100% (HN 100) to provide 44% crude protein and 20% crude lipid diets. Diets were fed to 125 rainbow trout to apparent satiation by hand twice daily at 09.00 and 16.00 hours under natural photoperiod conditions. At the end of the feeding trial, fish of all groups almost tripled their body weight and no significant difference (P>0.05) was revealed in final weight or specific growth rate between treatments. However, feed conversion ratio (FCR) of the HN100 group was significantly higher than other treatments (P<0.05). There was a slightly decreasing trend in protein efficiency ratio (PER) and net protein utilization (NPU) with increasing level of dietary hazelnut meal, but it was only significant in groups of fish fed HN100. All groups of fish displayed similar carcass and muscle compositions. According to the results of the present study, it can be stated that hazelnut meal can replace soybean meal at up to 200 g kg-1 in grow-out diets of rainbow trout without any detrimental effects on growth performance.

Chickweed (Stellaria media) Leaf Meal as a Feed Ingredient for Tilapia (Oreochromis mossambicus)

A study was undertaken to determine the effect of the inclusion of chickweed (Stellaria media) leaf meal (CLM) on growth performance, feed utilization, nutrition retention, and whole body composition of tilapia, Oreochromis mossambicus. Five isonitrogenous (35% crude protein) and isoenergetic diets were formulated to contain chickweed leaf meal at levels of 0%, 2.5%, 5%, 10%, and 20%. A 45-day feeding trial was carried out on triplicate groups of 225 mixed sex fish in 140-L fiberglass tanks. There were no particular differences in protein retention, fat retention, energy retention, whole body dry matter, and ash levels of fish fed experimental diets (P > 0.05). However, 20% chickweed supplementation significantly decreased final fish weight, weight gain, feed conversion ratio, whole body protein, and fat levels (P < 0.05), probably as a result of oxalic acid toxicity. Inclusion of CLM can be used at 10% in tilapia diets without significant reduction in growth.