Showing 23 results for Oncorhynchus Mykiss
Volume 1, Issue 1 (3-2013)
Abstract
The main concern in fish transportation is minimizing stress during transportation. In this study, the effect of zeolite and clove essence in terms of transportation on survival and stress rainbow trout was investigated. 4 treatments (each treatment included 3 replicate) including control treatment, clove essence (25 mg/l), zeolite (14g/l) and clove essence (25mg/l) + (14g/l) were considered. 156 fish (with average weight 80 ± 4.4 g) were randomly distributed with a 130 kg/m3 density. At time zero, 6, 12 and 18 hours after starting transportation, survival rates, cortisol and glucose levels (as indicators of stress) were measured and analyzed. In the end, results showed a significant difference in the survival rates that control treatment had the lowest survival rates (P
Abdolhamid Azari, Roshada Hashim, Ghobad Azaritakami, Aboulghasem Roohi,
Volume 1, Issue 4 (12-2013)
Abstract
An 84-day feeding trial was carried out onfingerling (4.44 ± 0.06 g) rainbow trout (Oncorhynchusmykiss, Walbaum, 1792) to evaluate the effect of dietary supplementation with a commercial prebiotic GroBiotic®-A (G-A) on the growth, feed efficiency, haematology and immunlogical parameters. Ttreatments containing various inclusions of G-A (0 %, 0.5 %, 1.0 %, 1.5 %, 2.0 %, 2.5 %, and 3.0 %) were added to a commercial fish dietand were fed twice daily at 2-6 % of body weight. The highest weight gain (WG), specific growth rate (SGR) and average daily gain (ADG) were obtained in fish fed the diet containing 2.5 % G-A followed by 3.0 % inclusion (P<0.05). The highest feed efficiency (FE), protein efficiency ratio (PER) and net protein utilization (NPU) were also recorded in the 2.5 % G-A inclusion (P<0.05). Survival was significantly higher (P<0.05) in fish fed with 2 % and 2.5 % G-Asupplement (P<0.05). Although higher Hb, haematocrit, RBC, WBC, MCH, MCHC, MCV, lymphocytes, and neutrophils were observed at all G-A supplemented diets, the differences among themwerenot significant (P>0.05). On the other hand,significantly higher differencee (P<0.05) in lysozyme and immunoglobulin (IgM) concentrations wereobserved in 2.5% G-A inclusion. The results of this study indicated that 2.5 % G-A inclusionhad a better performance on growth and haematoimmunological parameters in rainbow trout fingerling.
Volume 2, Issue 3 (12-2013)
Abstract
The effect of the antioxidant extracts on the quality indices of rainbow trout fillet stored at refrigerator (4±1ºC) for 15 days was investigated. The fillets in 3 treatments, including salted in 10% brine, salted in 10% brine plus 1% nettle leaf extract, and salted in 10% brine plus synthetic antioxidant BHT were evaluated at every 3 days interval, using the quality indices including the free fatty acids (FFA), thiobarbituric acid (TBA), peroxide (PV), moisture content, pH levels and sensory characteristics. The results showed that TBA and FFA values increased significantly (p<0/05), but PV significantly decreased in all treatments during the course of storage (p<0/05). Samples containing antioxidants had significantly lower TBA, PV and FFA values in comparison with the control sample throughout the storage. Also, the methanol extract from nettle leaves (at 1% balance) controlled the TBA, PV and FFA indices and entirely replaced the synthetic BHT antioxidants (at 1% balance). Since the sensory evaluation (smell, texture, taste and after taste elements) showed no significant differences between the two antioxidants, both are recommended to preserve the quality of rainbow trout fillet. The nettle leaf extract was found to be more efficient on shelf life extension the fillet.
Volume 2, Issue 4 (3-2014)
Abstract
A 9-week feeding trial was conducted to determine the effect of dietary vitamin E levels (0, 100, 200 and 1000 mg kg diet) on the growth performance and hematological indices in rainbow trout (Oncorhynchus mykiss) fingerlings (initial weight of 2.1 ± 0.1). Results indicated significant effect (p<0.05) of vitamin E levels on the fish growth performance. In terms of hematological indicators, vitamin E levels significantly affected the hematocrit, hemoglobin, red blood cell (RBC) count, monocyte and eosinophil in rainbow trout. However, it did not change MCHC, lymphocyte and MCH values.
Volume 3, Issue 3 (12-2014)
Abstract
Morphological changes of the chloride cells and the α1b subunit gene expression of Na+-K+-ATPase in triploid rainbow trout (70.6 g average weight) were studied upon direct transferring to 6, 12 and 18 ppt salinities. Changes in abundance, distribution pattern, and the sectioned area of the chloride cells was studied through classic histology and Na+ K+-ATPase localization was performed through immunofluorescence light microscopy using a mouse monoclonal antibody IgGα5. Gene expression of Na+-K+-ATPase α1b subunit was studied by semi-quantitative gene expression methods.No mortality occurred among the fish in all salinities during the 10-days experimental period and treated fish kept their plasma osmolality at standard physiologic levels. All the fish also showed similar distribution pattern in their chloride cells that were distributed on filaments, between and over lamella. Histological studies confirmed some abnormal morphological changes such as lamella interruption. Immunohistochemical studies showed the highest number of the chloride cells on lamella and between lamella in 18 ppt and the maximum sectional area of the chloride cells in freshwater. Gene expression of Na+-K+-ATPase α1b subunit had direct correlation with increasing trend of salinity. In conclusions, triploid rainbow trout was found to be adaptable to the various experimented salinities and could be recommended for rearing in brackish water.
Volume 5, Issue 1 (6-2016)
Abstract
The aim of this study was to assess the effects of triploidy induction on survival, growth performance, body composition and fatty acid profiles in rainbow trout. Eight female (1600±246 g) and 6 male (1393±186 g) of four-year rainbow trout broodstock were selected and stripped. Heat shock treatment achieved 10 min after fertilization, for 10 min and in 28˚C water bath. Based on red blood cell analysis, the overall triploidization success level was 87.1±1%.The survival rate from fertilization to eyed stage in triploid group (86.31 ± 1.21%) was significantly (p < 0.05) lower than that of diploid group (92.12 ± 1.59%). The survival rate from eyed stage to hatching in triploids (94.04 ± 1.33%) was significantly (p < 0.05) lower than that of diploids (98.10 ± 0.45%). Growth performance (initial and final weight, weight gain, specific growth rate and condition factor) was significantly higher in diploids as compared to triploids (p<0.05) after 38 days of rearing. Proximate compositions of fish including protein, fat and ash were not affected by triploidization, but triploids showed higher moisture content compared to that of the diploids. Moreover, the results showed that the levels of saturated fatty acids increased and the levels of unsaturated fatty acids decreased as an effect of triploidy induction.
Volume 5, Issue 2 (9-2016)
Abstract
Protein compounds were extracted from the mucus of sea anemone, Stichodactyla haddoni, and their effects on the gills of rainbow trout, Oncorhynchus mykisswere examined. Sea anemone samples were collected from the intertidal zone of the eastern coast of Hormuz Islandand frozen samples were transported to the laboratory. Then the mucus was extracted using of the PBS solvent and doses of 5, 10 and 24 mg/dry weight of total protein was injected into the tail vein of the fish. Upon the inactivation of fish, histopathological changes were examined using of the classical histological method. Lethal signs were observed in the gills, including aneurysm, hypertrophy of epithelial cells, lamella clubbing and deformation, subepithelial edema, lamella congestion in the interlamellar region and necrosis. The damages were more serious with increasing doses. The results showed that protein compositions of the mucus can cause numerous lesions in the gill tissue of fish, which act as an excretory, respiratory and ionic regulation tissue, the failure of which can lead to failure of fish’s vital functions that can be one of the reasons for the death of the hunted fish.
The results showed that the protein compositions of mucus can cause numerous lesions in the gill tissue, as an excretory, respiratory and ionic regulation tissue lead to failure of it functions that itself can be one of the reasons hunted fish death.
Volume 5, Issue 2 (9-2016)
Abstract
The present study was conducted to evaluate the effect of Lactobacillus plantarum (KC426951) isolated from the intestine of rainbow trout Guilan on growth factors, carcass composition and the intestinal bacterial flora of rainbow trout (Oncorhynchus mykiss) was conducted. Rainbow trout weighing 3.56±2.24 for 2 weeks were consistent with environmental rearing conditions. Five groups of fish were fed with diets containing 106 (T1), 107 (T2), 108 (T3), 109 (T4), 1010 (T5) cfu g-1 of L. plantarum and control group (T6) without diet containing probiotics were fed for 60 days. Results showed that final weight, final length, growth rate, percent weight were gained in treatment 2 the highest and 5 the lowest level in treated. Also, FCR lowest rates in treatment 2 and treatment 5 were accounted for most (p<0.05). The highest total count of lactic acid bacteria were obtained in the intestine of T4(p<0.05). Maximum carcass protein was observed in T4, and low fat content is related to the control treatment (p<0.05). According to the results obtained from the use of Lactobacillus plantarum could be considered as a positive factor for the improvement of the intestinal bacterial flora, growth performance and carcass composition could be used.
Volume 6, Issue 2 (9-2017)
Abstract
The effect of different lipid extraction methods (including, Bligh & Dyer, Smeds, Bligh & Dyer using Dichloromethane, Folch, Roese Gottible, Soxhlet used petroleum ether – dry and wet- and Soxhlet used N-hexane) on total fat and fatty acid composition in rainbow trout (Oncorhynchus mykiss) was investigated. According to the results, the Bligh & Dyer method showed a higher fat extraction efficiency than Soxhlet (wet), Smeds and Roese Gottible, while no significant difference was observed with the other methods. No significant differences were found in total SFA, total MUFA, and total PUFA of different extraction methods. The omega-3/omega-6 ratio ranged between 0.20-0.29. The highest amount of polyene index (PI) was 0.34, but no significant differences were found between different extraction methods. Taking fat quality and quantity, finance, toxicity, and theease of operation, the most efficient method for rainbow trout lipid extraction was the “optimized Bligh & Dyer using Dichloromethane”.
Volume 7, Issue 1 (3-2018)
Abstract
Aims: Increasing the aquatic consumption, developing aquaculture, and the need for aquatic food production will make unclear the availability to fish oil in the future. The aim of this study was to investigate the effect of replacement of fish oil by grape seed oil on growth indices and protease enzymes activity in Rainbow Trout.
Materials & Methods: This study was conducted on 450 Rainbow Trout during a 60-day period. In this study, control diet (A) containing 100% fish oil and 25% (B), 50% (C), 75% (D), and 100% (E) grape seed oil were used instead of fish oil. The data were analyzed by Graph pad prism and SPSS 20 software, using one-way ANOVA test.
Findings: The highest final weight and weight gain was in diet C and the lowest was in D, having a significant difference. Specific Growth Rate (SGR) and Protein Efficiency Ratio (PER) had no significant difference. The highest and lowest feed conversion ratio (FCR) was observed in diets E and C, respectively, with a significant difference. The highest fat efficiency was in diet C. The highest feed efficiency was in diets C and D and the lowest was in E, and the diets were not significantly different. The most activity of pepsin and trypsin was observed in pyloric additions in diet C and in intestine in C and D. The optimal amount of fish oil replacement was satisfied by grape seed oil 50% (diet C).
Conclusion: The diet containing 50% fish oil and 50% grape seed oil is effective in improving the growth indices and activity of pepsin and trypsin enzymes in Rainbow Trout.
Volume 7, Issue 2 (6-2018)
Abstract
Aims: Today, a part of studies on food science has investigated the effect of cooking methods on the oxidation of various types of meat and the use of natural herbal preservatives instead of synthetic preservatives. The aim of the present study was to evaluate the oxidative stability of pre-cooked rainbow trout (Oncorhynchus mykiss) fillet treated with Dill (Anethum graveolens L.) essential oil (EOs).
Materials and Methods: In the present experimental research, rainbow trout fillet with dill EOs and Butylated hydroxytoluene (BHT) were treated, each at 3 different concentrations, and cooked by 3 methods, including frying, oven baking, and steaming. The cooked samples were stored at -18◦C for 4 months and analyzed at the end of each month. The extracted oil was used to measure the value of free fatty acid (FFA), peroxide value (PV), and thiobarbituric acid (TBARS). The data were analyzed by SPSS 20, using two-way ANOVA, Tukey's post hoc, Kruskal-Wallis, and Mann-Whitney U tests.
Findings: The FFA formation showed increase in all samples, especially oven baked rainbow trout fillets (p<0.05). The highest value of PV was also obtained from the fried fillets treated by BHT. After cooking, TBARS values in treated samples with essential oil showed decrease in all samples cooked with EOs. FFA, PV, and TBARS increased in all samples, but the samples cooked with EOs had lower FFA, PV, and TBARS than the control samples.
Conclusion: In rainbow trout, the lipid oxidation increases with the thermal process, but the essential oil postpones the oxidation during the storage period as frozen. The samples cooked with Dill EOs have lower amount of FFA, PV, and TBARS compared with the control peers.
Volume 7, Issue 3 (9-2018)
Abstract
Aims: In this study, the replacement effect of dietary fish meal with AquPro (Processed soybean meal) was assessed on growth performance, body composition and total protease activity of rainbow trout (Oncorhynchus mykiss) over a period of 6 weeks.
Materials and Methods: In this experimental study, at the beginning of the trial, 5 experimental diets were formulated with fish meal as control (A) and diets with 25% (B), 50% (C), 75% (D) and 100% (E) AquPro, respectively. At the end of the feeding trial, growth performance, body composition and total protease activity from pyloric caeca and intestine were measured.
Findings: The results indicated that the WG, SGR and ADG in experimental diet C were the highest and showed a significant difference with other treatments (p<0.05). However, the status index in experimental diet C was lower than other treatments, but did not show significant differences (p>0.05). The moisture content, fat, and body ash were respectively, significantly higher in experimental diets A, B and E than those of other treatments (p<0.05), But the highest amount of protein was observed in the experimental diet of C, which did not show any significant difference with other treatments (p>0.05). The highest total protease activity from pyloric caeca and the intestine was observed in the fish fed with diet C which showed a significant difference with other diets (p<0.05).
Conclusion: Based on the results of growth performance, body composition, and total protease activity was revealed that the diet containing 50% AquPro could be appropriate for rainbow trout growth.
Volume 7, Issue 24 (4-2010)
Abstract
The biogenic amines content of whole rainbow trout (Oncorhynchus mykiss) and its related bacterial load (psychrotroph and psychrophiles, pseudomonads and mesophiles) were monitored during ice storage in a period of eighteen days (zero, 3, 6, 9, 12, 15 and 18). The levels of putrescine, cadaverine and histamine and bacterial loads increased (P<0.05) during storage but tyramine was not detected in any of the samples. Initial concentration of putrescine was 0.4 and finally reached to 8.97 mg/g, and psychrotroph and psychrophiles were the dominant microorganisms. The best correlatios were found among putrescine and psychrotroph and psychrophile and its regression equation derived relating PUT, pse and psy (R=./98): [PUT =0.83 pse + 0.69psy+ 0.41[. In adition another regression equation derived relating CAD and time (R=0.955): [CAD =0.576 time - 3.49[.It is therefore concluded that although the quality control of Rainbow trout can be approximately estimated by measurement of either putrescine or psychrophiles with the usage of derived equation, but it's much better to evaluate some of these factors simultaneously to accomplish a precise quality assessment.
Volume 8, Issue 1 (3-2019)
Abstract
The aim of the present study was to investigate the effects of ascorbic acid and density on reproductive performance and steroid hormones in rainbow trout (Oncorhynchus mykiss). In this regard, six treatments were considered included three diets containing 0, 100, and 1000mg ascorbic acid as L-ascorbyl-2-polyphosphate per kilogram of food in contrast to two densities 4.33kg/m3 and 2.16kg/m3. Triplicate groups of fish were fed one of the test diets for 16 weeks. A total of 81 females with an average weight of 812.1±1.5g were introduced to tanks (910 liters). At the end of the 16th week and when preparing fish for spawning, from each replication of high and low densities, 4 and 2 fish after bleeding of fish to measure the concentrations of progesterone, testosterone, and estradiol were spawned. After that, reproductive parameters such as work fecundity, ova per gram, and ova diameter were measured and then fertilized. During the incubation period, fertilization and mortality rates were recorded. The results showed the interaction between ascorbic acid and density and also the significance of this effect in reproductive parameters (number per gram of egg, oocyte diameter, coagulation, and fertilization percent; p<0.05). In the case of steroid hormones, the effect of treatments on the amount of each of the three hormones and their interaction on the level of estradiol and testosterone were significant (p<0.05), but the effect of density and diet on progesterone was not significant (p>0.05). The results of this study confirm the use of higher levels of ascorbic acid in breeders compared to grow-out period and also the positive role of this vitamin in reproductive indices.
Volume 8, Issue 32 (10-2011)
Abstract
Salting and vacuum packaging, each of them has disadvantages for fish preservation in non-frozen mode. This study was aimed to investigate the The effect of light salting, vacuum
packaging and their synergistic effect on on shelflife of rainbow trout (Oncorhynchus mykiss) fillet during storage at 4°C±1. For this purpose the rainbow trout fillets were brined in 10 salt solution and vacuum packaged. Measuring of PH, total volatile bases nitrogen compounds (TVB-N), tiobarbitoric acid (TBA), total viable microbial count (TVC) and sensory evaluations, were performed during 18 days in refrigerator temperature. Obtained results showed that all of chemical and microbial indices increased during storage period. PH, TBA and TVB-N indices and microbial growth in salted, vacuum packaged was lower than other treatments and in light salted treatment was lower than control group (p<0.05). The results of sensory evaluations showed that light salting of rainbow trout fillet situation improved these indices rather than control group. Salted vacuum packaged treatments had a better sensory evaluations scores than salted treatment (p<0.05). with regarded to allowable restrict of TVB-N indices (25 mg/100g fillet) and total viable count (6 Log cfu/g) and also sensory evaluations, light salting and salted vacuum package treatments increased the shelflife of rainbow trout fillet in 4°C about 3 and 7 days, respectively and the major problems of each method of salting and vacuum packaging was removed.
Volume 9, Issue 1 (1-2020)
Abstract
Aims: The present study intends to assess the toxicity of CuO and ZnO nanoparticles (NPs) at laboratory conditions on some pathogenic bacteria for the reared fish, as well as, a bioassay on rainbow trout.
Material & Methods: For this purpose, the sensitivity of them to the mentioned NPs with a reference antibiotic (florfenicol) was assayed through the well diffusion method, as well as, minimum inhibitory concentration (MIC) and minimum bacteriocidal concentration (MBC) were determined by microdilution technique. On the other hand, the lethal toxicity test has been accomplished to the calculation of median lethal concentration (LC50) on some rainbow trout (55.3±7.6 g) in static condition for the 96 consecutive hours. We use one-way ANOVA and Probit regression in order to data analysis.
Findings: Results show that NPs of copper oxide and zinc oxide could significantly inhibit the growth of Streptococcus iniae or kill it at 0.18 and 0.24 µg/ml and more, respectively. The comparison between LC50-96h quantities of CuO NP (107.4 µg/l) and ZnO NP (102.3 µg/l) indicated that the CuO NP has more toxic potential.
Conclusion: According to the laboratory findings, the susceptibility of S. iniae and L. garvieae to ZnO NP were close to florfenicol. The mortality in the fish species due to lethal toxicity would occur if the effective concentration of NPs on the bacterial pathogenic agents being used directly.
Volume 9, Issue 1 (1-2020)
Abstract
Aims: The aim of this study was to investigate the effect of dietary lemon peel (Citrus limon) essential oil on growth, hematological parameters, some of serum biochemical parameters and liver enzymes in rainbow trout (Oncorhynchus mykiss) juveniles. Materials & Methods: For this purpose, 144 rainbow trouts with an average initial weight of 95.05 ± 0.41 g were randomly stocked in four treatments containing different levels of lemon peel essential oil ( 0 (control), 200, 400 and 600 mg lemon peel essential oil/kg diet) and fed for eight weeks. Findings: The results showed the highest growth factors in treatments of 400 and 600 mg lemon peel essential oil/kg diet (p<0.05). Inclusion of essential oil in diet increased hematological parameters as compared to the control except MCV, MCH, MCHC and increased serum biochemical parameters by contrast to the control except glucose, triglyseride and cortisol (p<0.05). liver enzymes of ALT and AST showed no significant differences among treatments containing essential oil and LDH exhibited no significant differences among 400, 600 mg essential oil/kg diet and the control treatment (p>0.05), but ALP amount significantly increased in essential oil treatments in a comparison to the control (p<0.05). Conclusion: Overall, these results indicated using 400 mg essential oil in rainbow trout diet could improve growth, hematological and some serum biochemical parameters of rainbow trout without any negative effects on liver.
Volume 9, Issue 4 (11-2020)
Abstract
The present study intends to assess the effects of Na diformate oral use with citric acid on some skin mucosal immunity indices (total protein, total immunoglobulin (TIg), lysozyme, protease, esterase, and alkaline phosphatase (ALP)) of rainbow trout following experimental challenge with Yersiniosis agent (Yersinia ruckeri). Subsequent to the determination of the 7-day median lethal dose (LD50) of Yersinia ruckeri, fish were stocked in eight groups and two repetitions. The acidifiers separately with a dose of 0.2%, and combined 0.1+0.1% was added to the commercial diet. Five days after inoculation, feeding of fish with acidifiers commenced, and following 15 days, the mucus samples were gathered from the skin of anesthetized fish to measure immune indices. Results showed that the 7-day LD50 of Y. ruckeri was 8.91×105 CFU/ml. In the main experiment, findings indicated the significant effect of Na diformate on the increased levels of mucoid total protein and proteolytic activity of healthy or diseased fish. The acidifiers-contained diet because of potentially having synergistic effect caused inducing the mucus TIg. It seems that the orally use of Na difirmate in 0.2% of the diet separately or combined with citric acid, at least for 15 days, can improve the cutaneous mucus immunological indices that its result is an increase in the survival rate of farmed rainbow trout.
Volume 11, Issue 2 (5-2022)
Abstract
This study was conducted from April 2017 to June 2018 in a Trout aquaculture farm in Firoozkoh, Tehran province, to distinguish environmental and managerial risk factors affecting incidence of viral diseases in the fish farm under study. Averaged visit from fish farm was 2 times a month and all biosecurity measures were advised and applied during every visit. Some of the physico-chemical parameters were recorded daily. Samples from all cargoes of eyed-eggs imported from abroad and also from larvae after active swimming and absorption of yolk sac were taken for RT-PCR test. Virology, bacteriology, parasitology and mycology tests in the farm and authorized laboratory were done. Clinical observations, macroscopic and microscopic examinations, checking all the sanitarian and productional managerial factors, also checking all the physical and chemical factors affecting the outbreak of viral diseases were done. During clinical observation of fishes, these symptoms were observed; anorexia, gathering at the raceway’s side and outlet, cachexia, one and two side exophthalmia, melanosis, integument ulcers, hemorrhage in ventricular and ocular areas, petechia in ventricular area, fecal casts, high mortality and also presence of a large number of moribund fishes. The result of the laboratory examinations was IHN positive of Rainbow trout fries. This disease caused about 80% mortality of the fries produced from the imported eyed-eggs cargo. The other fatalities with different reasons were also recorded such as; the Lutra’s attack at nights, the farm’s personnel running amongst other farms and transferrin pathogens, the transportation vehicles not being proper disinfected while inter to and exit from the farm and the severe food intoxication of fries. Regarding the results of this study, instruction of scientific and practical models has presented to decrease the effect of environmental and managerial risk factors in the incidence of the disease.
Volume 12, Issue 48 (9-2015)
Abstract
The aquatic zoonotic bacterial Streptococcus iniae represents a threat to the worldwide aquaculture industry. This study was carried out to evaluate the antibacterial activity Cuminum cyminum essential oil and nisin for control of S.iniae in fillets of Rainbow trout (Oncorhynchus mykiss) in 4 Cº on basis hurdle technology between 2012 and 2013.The effect of different concentrations of nisin (0, 0.25 and 0.75 µg/ml) and Cuminum cyminum (0, 0.005, 0.135 and 0.405 %) were conducted on growth of S.iniae GQ850377 for 15 days. The results showed that growth of bacterial delayed in samples treated with nisin and essential oil singly to 9 days and together to 3 days. Samples treated with essential oil showed a significant decrease on the growth of the bacteria compared with nisin and control sample (P<0.05). No significant different was observed on the growth of S.iniae in samples treated with higher concentrations of C.cyminum (0.135 and 0.405 %) (p>0.05), but different concentrations of nisin was statistically significant (p<0.05). Synergistic effects were observed at concentration of 0.405% C.cyminum and 0.75 µg/mL nisin.
