جستجوی مقالات مرتبط با کلیدواژه « قزل آلای رنگین کمان » در نشریات گروه « دامپزشکی »

In this study, we examined the effects of free and microencapsulated liposomes containing rosemary essential oil (REO) on the microbiological and physicochemical properties of rainbow trout meat coated with carboxymethyl cellulose (CMC). The essential oil was extracted using a Clevenger, and nanoliposomes of the essential oil were produced through a combination of thin-layer hydration and ultrasound waves. Gas chromatography-mass spectrometry analysis revealed that the main components of REO were compounds 1-8, cineole (30.03%), and alpha-pinene (13.09%). Antioxidant activities measured by the DPPH method were 72.21% for free REO and 71.8% for microencapsulated REO. Both types of REO nanoliposomes were separately applied with CMC to create an edible coating for rainbow trout meat, which was stored at 4°C for 15 days. Our findings on the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of REO and its nanoliposomes against Escherichia coli and Staphylococcus aureus showed that REO nanoliposomes had a significantly lower effect compared to free REO (p< 0.05). Moreover, the growth of live bacteria, psychotropic bacteria, lactic acid bacteria, and enteric bacteria in samples coated with CMC and REO nanoliposomes was significantly reduced compared to other samples and was lower than in samples with free essential oil (p<0.05). Overall, using CMC with either free REO or REO nanoliposomes effectively reduces the microbial and chemical deterioration of rainbow trout during storage.

Numerous studies have investigated the positive effect of chitosan and nano-chitosan loaded clinoptilolite on growth performance, digestive enzyme activity, and intestinal histomorphology in different fish species. However, there are no data evaluating the potential effect of the composites on the fish stomach.

In the current study, the effects of chitosan and nano-chitosan loaded clinoptilolite on histological features and pepsin activity in the rainbow trout stomach were considered.

Chitosan and nano-chitosan loaded clinoptilolite were synthesized, and then two hundred and forty fish (~27.75 g) fish were distributed in eight groups each in three replicates. Ten days after adaptation, the fish were fed with eight diets, including control diet (CTR), clinpotilolite (T1), chitosan composites (T2, T3, T4), and nano-chitosan composites (T5, T6, T7) for 70 days. Afterward, all fish in each tank were anesthetized in clove extract (50 μl/l), and tissue samples were obtained for pepsin activity (n= 5) and histological assay (n = 5).

The groups administrated with nanochitosan composites showed the highest pepsin activity (P˂0.05). Additionally, histological examinations exhibited a higher epithelial height, increased mucosal density, and oxynticopeptic cells hypertrophy in fish fed composites compared to the CTR group (P˂0.05). Meanwhile, nanochitosan composite administration could cause higher reaction of secreted granules to periodic acid–Schiff (PAS) staining.

The findings demonstrated the potential application of chitosan and nano-chitosan loaded clinoptilolite composites for improvements in the histomorphology and pepsin activity of the rainbow trout stomach, resulting in higher growth performance.

In recent decades, several studies have been performed on the evaluation of probiotics in fish and their positive has been reported on different species. In this study, rainbow trout (Oncorhynchus mykiss) with 115±2 g average initial weight were randomly assigned to tanks and fed with different levels of Weissella confusa (0 [control] and 3 g W. confuca powder per 10 Kg diet [3× 107 CFU/g count]) for 8 weeks. At the end of the experiment, tissue samples were taken from different parts of the intestine and fixed in 10% formalin. After tissue preparation, sections were stained with hematoxylin-eosin. The results showed that morphology parameters including villi length and width in the anterior and posterior intestines of the treatment group were significantly increased compared to the control group (P<0.05). According to the results, W. confusa probiotic can have positive effects on intestinal morphology and its absorptive surface area in rainbow trout.

Bisphenol A (BPA) is a chemical used in the manufacture and hardening of plastic products. Iran is one of the top 10 countries in the world in terms of consumption of plastic products, and as a result, the release of plastic waste turns into the release of substances such as BPA in water resources and in aquaculture systems. One of the ways to evaluate the presence of chemical factors in the environment of fish is to measure antioxidant defense indicators in fish tissues. This study investigated the antioxidant defense responses of rainbow trout exposed to BPA. The liver tissue of 110 pieces of rainbow trout (55 ± 0.4 grams) were sampled after 14 days of experimental fish exposure to zero, 10 and 50 micrograms per liter of BPA for antioxidant defense indicators assay such as catalase, superoxide dismutase, malon di-aldehyde and glutathione peroxidas. All indicators were significantly increased after exposure period of 14 days to 10 and 50µg/L of BPA (P˂0.05) which confirms the possibility of benefiting from these indicators in following the trace pollution with plastic products in the water and food sources of humans and the aquatic environment.

Streptococcosis is one of the most critical and economically damaging diseases in the aquaculture industry, especially in rainbow trout, and it causes much damage to this industry annually. On the other hand, this disease is most common among humans and fish, leading to disease among consumers of infected fish. To survey the incidence and etiology of rainbow trout suspected of streptococcosis, 50 samples of alive trout which had symptoms similar to streptococcosis were captured from selected farms in Yasuj province. After the autopsy, bacterial sampling of the kidney, liver, and brain was done on a Blood Agar medium. Sampling was done near the flame and with sterilized instruments. Samples were taken to the laboratory of the veterinary school of Islamic Azad University, Kazerun branch, and kept in an incubator for 72 hours at 25 degrees centigrade. Then, gram-negative samples were omitted by the Gram-stain technique and catalase tests, and then complementary biochemical tests were performed after recultivating the samples. The results showed isolated bacteria, including Streptococcus iniae and Lactococcus garvieae. The incidence of infected rainbow trout with a clinical sign of S. iniae and L. garvieae was 68% and 25%, respectively. Infection was not isolated from 7%. Isolation of S. iniae and L. garvieae from kidney, brain, spleen, and liver was 60%, 65%, 58%, 92%, and 26%, 36%, 32%, and 6%, respectively.

Lactococcus garviea is a gram positive, facultative anaerobic, oxidase and catalase negative that belong to the lactic acid group bacteria. This bacterium is the cause of Lactococcosis, an acute disease with hemorrhagic septicemia in rainbow trout and causes a lot of economic damage to the aquaculture industry. In this study, 10 diseased rainbow trout were bacteriologically sampled from head kidney and brain in one of fish farms of Khuzestan province, Located in Masjed Soleyman. The obtained isolates were further evaluated by biochemical tests and molecular method (with 16S rRNA specific primers). Samples were also taken from different organs and fixed in formalin 10% for pathological examination. To investigate the lesions, sections were prepared from 5 μm and stained with Hematoxylin-Eosin. The results of bacterial culture, biochemical tests and PCR confirmed the presence of Lactococcosis in the studied farms. Macroscopic examination revealed lesions in the liver, kidneys and intestine of affected fish. The liver was pale and the kidneys were relatively swollen. No other complications or lesions, including abdominal discharge, were observed in affected fish. In histopathologic examination of liver, degeneration, and focal necrosis were seen. In kidneys, tubules degeneration and melanomacrophage cells accumulation were seen. In intestines, moderate inflammation and inflammatory cells aggregation was seen. According to the confirmation of the presence of lactococcosis, it is necessary to take measures to prevent lactococcosis (especially vaccination).

Viral Hemorrhagic Septicemia is one of the most important infectious diseases of cultured fish, causing mass mortality, especially in rainbow trout. This study aimed to investigate the occurrence and pathological lesions of VHS in Chahrmahal va Bakhtiari, Lorestan, and Isfahan Provinces, between 2014 and 2018. The virus was identified using the RT-PCR method in clinically suspected fish. According to the obtained results, 202 samples (13.33%) of 1515 studied samples were infected with Viral Hemorrhagic Septicemia Virus. The infection rates during the study were 14.65% in Chaharmahal va Bakhtiari, 15.16% in Lorestan, and 8.5% in Isfahan Provinces. Comparison of the infection rate in fish with different weights indicated that the highest level of infection was in the fish weighing above 200 g (28.22%). The infection rate in fish with 5-200 g and 1-50 g weight was 19.44 and 8.6%, respectively. Considering that the disease has been fluctuating in the range of 9-19% during the study, full-scale and drastic actions are necessary for eradicating Viral Hemorrhagic Septicemia.

The present study was conducted to compare the histology of renal proximal tubules (I) and (II) in two species (Rainbow trout and Oscar). Rainbow trout, known as Oncorhynchus mykiss scientific name from the Salmonidae family which is cultivated and freshwater. Oscar fish, the scientific name is Astronotus Ocellatus, which is one of the most well-known ornamental fish of the Chichlidae family. Five piece of the two fish species were selected randomly and their macroscopic specification and morphometric measurements were recorded. Samples were fixed in %10 formalin buffer and the cuts were prepared with a thickness of five micron and then they were stained by Hematoxylin and eosin and Periodic acid–Schiff method and studied by light microscopy. The data were analyzed with SPSS software and T-Test statistical test (P <0.05). Proximal and distal tubes were detected and the variables were measured. The size of the cell nucleus and the outer diameter of the proximal (I) had a significant difference (P<0.01). There has been significant difference in the number and the size of cell and its nucleus, the inner and outer diameter of the proximal II between two species (P<0.001). The number, cell size of the distal tubules has been significant difference between two species (P<0.01). The size of the cell nucleus, the inner and outer diameter of the distal tubules have been significant difference between two species (P<0.001). According to the results, the anatomy and histology of kidney tissue are different in the Rainbow trout and Oscar fish.

Intensive aquaculture and commercialization production are believed to be needed for improving fish health status and probiotics are candidates to achieve this goal.

In this study, we utilized Lactobacillus plantarum and Lactobacillus pentosus as autochthonous food supplementation for biochemical investigation in rainbow trout.

In the current study, 240 juvenile rainbow trout with an average weight of 15 ± 2 g were randomly divided into four groups with three replications. Group 1, 2, and 3 were fed with 108 CFU/g of L. plantarum, L. pentosus, and the combination of these two probiotics, respectively. The control group was fed with the normal diet, for 60 days (2 % of body weight, 3times per day). Samples were taken at days 0 and 60 and biochemical parameters and hepatic enzymes activity were then investigated.

Most biochemical factors had positive changes in the fish fed with probiotics, particularly in L. plantarum group (p < 0.05). Furthermore, the results exhibited a significant decrease in ALP level in the probiotic groups, particularly in L. pentosus group (p < 0.05). Meanwhile, AST enzyme activity in plantarum+pentosus group was higher than that in the other groups (p < 0.05).

The present results indicated the effectiveness of food supplementation with probiotics in fish diet with the preference of probiotic to improve the biochemical factors and hepatic enzymes activity of rainbow trout, Oncorhynchus mykiss.

Some herbs have a wide range of beneficial properties, including stimulating and strengthening the immune system, their use in fish farms improves growth. Sixty healthy rainbow trout were selected with 150 g weight. They were randomly divided into 2 groups of 30 each with 3 replications. The essential oil was added to the daily diet with 10 g / kg feed and after 3 months the fish were assayed and sampled. some blood parameters was performed. The results showed that the control group had lower food conversion ratio (p < 0.05). Also, consumption of essential oil at this dose had negative effect on liver function and liver enzymes significantly increased (p < 0.05). Total protein, albumin, and blood glucose were decreased and uric acid and creatinine were significantly increased (p < 0.05). The blood cells were significantly decreased. In the histological examination around the central veins of liver was severe degeneration. Evaluation of blood biochemical values showed that AST, ALT in the treatment group significantly increased and total protein and albumin in the treatment group decreased significantly (P <0.05). Uric acid was significantly higher in the treated fish than in the control group (P <0.05).oral administration of Pistacia atlantica essential oil at this dose is not recommended in rainbow trout and causes tissue damage.Until it is decided whether or not to consume or conditionally consume these essential oils and to increase the efficiency of production and productivity in the country by increasing the clinical and localization of the country in fish farms.

Fish and other aquatic animals, directly and indirectly, can be contaminated with Listeria monocytogenes and consequently, fish and their products are considered a carrier for this bacterium. The present study investigated the contamination of farmed rainbow trout and common carp with this bacterium as well as the phylogenetics of the isolates. A total of 50 samples of farmed fish were obtained from local fish supply centers in Shahrekord City from July to September 2018. Based on the molecular experiments, 18 (36%) of the 50 studied samples were contaminated with L. monocytogenes as 26% and 10% of the isolates were found in trout and carp, respectively. From 18 isolates, 12 samples (66.66%) belonged to serotype 4b, one belonged to serotype 1/2a and the other 5 samples belonged to serotype 1/2b. According to the results of the present study and regarding the importance of the bacteria in terms of public health, continuous and accurate hygienic monitoring seems to be necessary.

In this study, the effects of selenium nanoparticles on the reproductive performance of rainbow trout breeders (Oncorhynchus mykiss) were investigated. A total of 84 male reproductive strains were selected from among the breeders of the Genetic and Genetic Research Center of Shahid Motahari Yasouj. After adaptation, the fish were divided into 4 experimental groups with 3 replications. Male broilers fed with commercial foods (without selenium nanoparticles) (control group) and male brooders fed diets containing 0.5, 1 and 2 milligrams of selenium nanoparticles per kilogram of diet. After evaluating the quantity and quality of sperm, replication and fertilization were performed for different groups using female oocytes. The results showed that the highest volume of sperm and the highest sperm density were observed in rainbow trout fed with 2 mg selenium nanoparticles per kilogram of diet. The lowest sperm volume was observed in the control and 0.5 mg selenium nanoparticles and the lowest sperm density was observed in the control group. The duration of sperm motility in fish fed diets containing selenium nanoparticles (0.5, 1 and 2 mg) was significantly higher than that of the control group fed with selenium nanoparticle diet. No significant difference was found between the percentage of sperm motility and spermatocrit between experimental groups. The highest percentage of fertilization, laceration and hatching of eggs were from rainbow trout breeders fed with 2 mg nano-selenium per kilogram of diet. In this study, the supplementation of the male breeder diet with selenium nanoparticles did not have a significant effect on progeny survival at the onset of active feeding. Selenium nanoparticles seem to have a positive effect on hatching eggs ob n embryos and larvae, but in the onset of active nutrition, there is no significant effect on the survival of larvae. selenium nanoparticles of diet improve the reproductive performance in male rainbow trout.

In recent years, the use of natural substances in nanoparticle forms in the aquatic animal diet is routine to improve the growth performance, immune system, disease resistance and fillet quality. In this study for the first time, the effects of zeolite/chitosan and zeolite/nanochitosan composites in rainbow trout diet on fillet quality were evaluated. Therefore, six treatment diets including zeolite/chitosan and zeolite/nanochitosan composites were prepared as follows: control group (without any additives), Z group (with 14.28 g kg-1 zeolite), Ch0.5% group (with 0.5 g kg-1 chitosan loaded in 14.28 g kg-1 zeolite), Ch5% group (with 5 g kg-1 chitosan loaded in 14.28 g kg-1 zeolite), NCh0.5% group (with 0.5 g kg-1 nanochitosan loaded in 14.28 g kg-1 zeolite) and NCh5% group (with 5 g kg-1 nanochitosan loaded in 14.28 g kg-1 zeolite). Prepared diets were fed to rainbow trout with a mean weight 50 g for 60 days. On day 60, fish were weighed, and growth parameters were evaluated. Then, microbiological and chemical parameters during three months period in freezing storage temperature (-18) were studied. Results showed that growth performance was enhanced in all treatment groups, but bacterial growth did not change by experimental diets. Meanwhile, lipid peroxidation product and peroxide value significantly decrease in fish fillet administrated with NCh5% diet. This study showed that the administration of zeolit/nanochitosan composite at 5g/kg to rainbow trout diet could improve the fish fillet in terms of chemical characteristics.

Replenishing fish oil with vegetable oils and using dietary supplements plays an important role in the metabolism of fats in aquatic animals. Corn oil is one of the vegetable oils that can be a good alternative to fish oil.

The aim of this study was to investigate the effects of replacing fish oil with corn oil and the use of dietary supplements L-carnitine and betaine on the metabolism of fats and blood indices of rainbow trout.

450 rainbow trout (9.12±0.26 g) were divided into four treatments (three replicates) and were fed with manual diet containing fish oil (1st treatment), corn oil (2nd treatment), fish oil with 500 mg/kg of food containing L-carnitine and betaine (3rd treatment) and corn oil with 500 mg/kg of food containing L-carnitine and betaine (4th treatment) for eight weeks. At the end of study, fatty acid profiles of the treatments were determined by gas chromatography (GC) and blood indices and their weights were also examined.

At the end of the experiment, the weight index did not show a significant difference. In the replacement of fish oil with corn oil, the levels of PUFA n-3, C18:3n3, C20:3n3, C20:5n3 and C22:6n3 fatty acids significantly decreased in fish carcasses and the PUFA n-6, C18:2n6, C20:2n6 and C20:4n6 increased significantly, but no significant difference was observed in total SFA and MUFA fatty acids. L-carnitine and betaine increased the EPA accumulation in fish oil and corn oil significantly, and the number of white blood cells in corn oil, L-carnitine and betaine fed fish (fourth treatment) were increased compared to fish oil treatment (first treatment), significantly (p < /em><0.05).

Considering the effect of corn oil, L-carnitine and betaine supplements on increasing the n-6 PUFA fatty acids, essential EPA and white blood cell counts, the use of corn oil and L-carnitine and betaine supplements in rainbow trout diet is recommended.

Nowadays, the tendency to use food packaging with antimicrobial activity of natural origin has increased. The use of edible and biodegradable films has been considered as an appropriate alternative to non-degradable plastic coatings.

In this study, the effect of coating with wheat starch and Pennyroyal (Mentha pulegium essential oil was investigated on microbial and physicochemical characteristics of rainbow trout fillet in cold conditions.

For this purpose, different treatments under the influence of starch, starch and Pennyroyal essential oil (1%), starch and Pennyroyal essential oil (2%) were prepared and physicochemical and microbial changes were evaluated at specified intervals (0, 4, 8, 12 and 16 days).

In the microbial test, the count of total bacterial and other bacteria by starch and starch + 1% and 2%, the essential oil was decreased in different days, also the difference between the control group and other treatments was significant (p < /em>≥0.05). The highest effect of pH reduction belonged to starch + 1% and 2% essential oil in different studied days. The level of pH was not different among different treatments on day 0 of storage. However, there was a significant difference between the control group and treatments on the fourth, eighth, twelfth, and sixteenth days of storage (p < /em>≥0.05). The results of the oxidative test showed that on the 16th day of storage, the lowest level of TBA was related to the treatment with starch + 2% essential oil and the highest value was related to the control group. In fact, the application of the coating layer delayed the oxidation process.

This study demonstrated antioxidant and antibacterial properties of the composition of edible starch and pennyroyal essential oil on the increased shelf-life of Rainbow trout fillet.

The use of natural immune stimulants is one of the most effective methods for strengthening immunity and preventing diseases in fish.

Due to the abundance of red algae (Laurencia caspica) in the Caspian Sea, the aim of this study was to investigate the effect of this algae on growth performance and blood indices of rainbow trout.

The present study was performed on 750 randomly selected rainbow trout (Oncorhynchus mykiss) in 5 experimental treatments including an algal extract-free diet (control), and diets supplemented with 0.5, 1, 1.5, and 2% of algal hydroalcoholic extract. During the experimental period, fish were sampled to measure growth performance and blood indices every two week for 8 weeks.

Growth indices were not affected by the algal extract at the end of eight weeks of feeding. There were no significant differences in fish survival at different treatments. Total counts of red blood cells, white blood cells, hematocrit percentage, hemoglobin concentration and neutrophil and monocyte percentages were affected by algal extract with significant increases compared to the control group (p < /em><0.05). Results of serum biochemistry showed that significantly increased total protein, albumin and globulin and also significantly reduced ALT, AST and ALP compared to the control in rainbow trout.

Based on the results of this study oral use of red algae (L. caspica) as an immune stimulant in rainbow trout (O. mykiss) was recommended.

The present study aimed to isolate and identify superficial fungal flora of the skin and gills of rainbow trout in the Shahrood city. Specimens were taken from the gill and skin of 100 rainbow trout from 5 fish farms during winter and spring, then were cultured on SDA and GPA medium. Isolated fungi were identified according to the colony morphologies and microscopic characteristics. In this study, 11 genera of fungi, including Aspergillus sp., Fusarium sp., Phoma sp., Cladosporium sp., Alternaria sp., Penicillium sp., Rhodotorula sp., Candida sp., Geotricum sp., Trichosporon sp., and Malassezia sp. were isolated that Phoma sp. and Fusarium sp. are pathogenic aquatic fungi. The most prevalent fungi were related to Aspergillus (16.66% on the skin and 23.8% in gill). Variety of isolated fungi indicated that sanitary and environmental condition of the farms are unfavourable and would cause a decrease in total production, an increase of fungal infection and treatment cost. Ecological differences play an important role in the species diversity of superficial fungal flora.