Fish & Aquatic
Alireza Afzali-Kordmahalleh; Saeid Meshkini
Volume 14, Issue 11 , November 2023, , Pages 625-630
Abstract
The effects of resveratrol as an anti-oxidant in improving growth and health have been shown in several experiments. This study aimed to evaluate the effects of different dietary resveratrol inclusion levels on digestive enzymes activity and serum biochemistry of rainbow trout (Oncorhynchus mykiss). ...
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The effects of resveratrol as an anti-oxidant in improving growth and health have been shown in several experiments. This study aimed to evaluate the effects of different dietary resveratrol inclusion levels on digestive enzymes activity and serum biochemistry of rainbow trout (Oncorhynchus mykiss). Accordingly, 225 juvenile rainbow trout with an average body weight of 10.00 ± 1.50 g were stocked in nine experimental units. The study was performed as a completely randomized design including three dietary levels of resveratrol as follows: 0.00, 400 and 800 mg kg-1 feed. During the experiment, fish were fed based on their respective body weight using standard feeding tables at three feeding times for 8 weeks. Nine fish were randomly selected from each treatment at the end of the 4th and 8th weeks of the experiment. Results revealed that supplementing 800 mg kg-1 feed resveratrol significantly increased lipase activity (31.40 ± 0.32 U mg-1 protein) compared to the control group (29.92 ± 0.52 U mg-1 protein) at the end of week eight. Also, at the same time, it increased serum high-density lipoprotein (123.04 ± 1.57 mg dL-1) compared to the control group (97.055 ± 1.463 mg dL-1). In addition, dietary supplementation of 800 mg kg-1 feed resveratrol effectively reduced serum alanine aminotransferase, alkaline phosphatase and aspartate aminotransferase activities along with glucose, cortisol and cholesterol. In conclusion, resveratrol can be used as a suitable food supplement to improve fish health by increasing digestive enzymes activities.
Sadigheh Shabanzadeh; Saber Vatandoust; Seyed Mehdi Hosseinifard; Najmeh Sheikhzadeh; Amir-Ali Shahbazfar
Volume 14, Issue 2 , February 2023, , Pages 97-104
Abstract
The potential of commercial astaxanthin on growth, biochemical factors, and antioxidant-related gene expression following a challenge with diazinon were studied in rainbow trout (Oncorhynchus mykiss). Fish (~ 20.70 g) were fed diets containing commercial astaxanthin (ASX) at 0.00 (CTR and ASX0), 0.50 ...
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The potential of commercial astaxanthin on growth, biochemical factors, and antioxidant-related gene expression following a challenge with diazinon were studied in rainbow trout (Oncorhynchus mykiss). Fish (~ 20.70 g) were fed diets containing commercial astaxanthin (ASX) at 0.00 (CTR and ASX0), 0.50 (ASX1), 2.00 (ASX2), and 5.00 (ASX3) g kg-1 for 60 days. Afterwards, the treated fish (ASX1, ASX2, ASX3) as well as the fish in ASX0 group were challenged with diazinon (0.11 mg L-1) for 96 hr whereas fish in the CTR group was not challenged with diazinon. Results showed that growth pattern improved significantly with all enriched diets compared to the ASX0 group. Metabolic enzyme activities, including alanine aminotransferase and alkaline phosphatase decreased in ASX2 and ASX3 groups with respect to the ASX0 group. Serum antioxidant status also showed the same pattern with enhancement in the fish fed with the ASX2 and ASX3 supplemented diets. Feeding the fish with astaxanthin, particularly in the ASX3 group, up-regulated the expression of some antioxidant-relevant genes, including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), and nuclear factor erythroid-2 related factor 2 (Nrf2) in the kidney and liver. Besides, the histopathological damages in kidneys and liver induced by diazinon were less pronounced in the ASX2 and ASX3 groups compared to the ASX0 group. In conclusion, commercial astaxanthin, especially at 5.00 g kg-1, enhanced the growth performance and ameliorated the oxidative stress induced by diazinon in rainbow trout.
Fish & Aquatic
Shima Khezrian; Amir Parviz Salati; Naser Agh; Hossein Pasha-Zanoosi
Volume 11, Issue 1 , March 2020, , Pages 83-88
Abstract
This study was undertaken to investigate the effects of feeding rainbow trout (Oncorhynchus mykiss) broodstocks with different ratio of plant oils to evaluate the changes in antioxidant defense status in the progenies. In the experimental diets, fish oil was replaced with different combination of plant ...
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This study was undertaken to investigate the effects of feeding rainbow trout (Oncorhynchus mykiss) broodstocks with different ratio of plant oils to evaluate the changes in antioxidant defense status in the progenies. In the experimental diets, fish oil was replaced with different combination of plant oils including corn oil, olive oil, sunflower oil, and coconut oil, to gain different levels of polyunsaturated fatty acids (PUFA) and highly unsaturated fatty acids (HUFA) in the experimental diets. Fish fed eight weeks with experimental diets before reproduction. After spawning, samples were taken on days 0, 5, 10, 15, 20, 25, 30 and 35 after fertilization. The samples were homogenized, centrifuged and the supernatant was removed for determination of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) activity and malondialdehyde (MDA) content. Results showed that SOD activity was significantly increased from the first sampling to day 35 in all treatment groups. The CAT activity showed a downward trend, as the highest CAT activity was observed in the eggs immediately after fertilization. The GPX activity declined until day five and then showed an increasing trend. The MDA content did not show significant changes in different groups and at different sampling times. The antioxidant enzymes activity was significantly influenced by the dietary PUFA level in the experimental groups but no change in MDA content was recorded, suggesting that the different percentages of fish oil replacement used in this study could not result in oxidative stress in early life stages of O. mykiss.
Microbiology
Meryem Cansu Yesiltas; Ilhan Altinok; Rafet Cagri Ozturk
Volume 10, Issue 2 , June 2019, , Pages 101-107
Abstract
Lactococcosis disease incident caused by Lactococcus garvieae has been increased with increasing aquaculture productions and outbreaks of the disease have become a threat on farmed species. To prevent lactococcosis, inactivated vaccine has been used, however, it only provides protection when given by ...
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Lactococcosis disease incident caused by Lactococcus garvieae has been increased with increasing aquaculture productions and outbreaks of the disease have become a threat on farmed species. To prevent lactococcosis, inactivated vaccine has been used, however, it only provides protection when given by injection. Other than inactivated vaccine, various vaccines such as subunit vaccines can be developed. In the present study, total protein profile of 43 strains of L. garvieae isolated from fish, milk and cheese by SDS-PAGE and virulence associated immunogenic proteins of L. garvieae strains using western blot with hyper-immune rabbit sera were determined. After analyzing whole-cell lysate protein of L. garvieae strains with SDS-PAGE, protein bands were ranged between 8.00 and 140.00 kDA. Among strains, variable protein bands were ranged between 17.00 and 48.00 kDa with some variability in the staining intensity of the protein bands and formed in 6 clusters. The immunogenic protein bands were ranged between 25.00 - 75.00 kDa. Only a variable and highly immunogenic protein band was observed between 40.00 and 45.00 kDa. Most of the strain including Lgper had 44.00 kDa immunogenic protein while nonvirulent ATCC strain had 42.50 kDA immunogenic protein. Predominant immuno-reactive proteins encoded by genes can be used as a subunit vaccine.
Food Hygiene
Fatemeh Esmaeli; Hossein Tajik; Tooraj Mehdizadeh; Mahsa Maiely
Volume 10, Issue 2 , June 2019, , Pages 109-117
Abstract
In the present study, the antioxidant and antimicrobial effects of essential oil (EO) and extract of Pimpinella affinis on the shelf life of rainbow trout during storage at refrigerator temperature based on three indicators of microbial, chemical and sensory quality parameters were evaluated. For this ...
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In the present study, the antioxidant and antimicrobial effects of essential oil (EO) and extract of Pimpinella affinis on the shelf life of rainbow trout during storage at refrigerator temperature based on three indicators of microbial, chemical and sensory quality parameters were evaluated. For this purpose, fish samples were stored in zein coatings containing 1.00% EO and 2.00% extract and in combination treatment containing 1.00% of each of them in refrigerator for 12 days. All of treatments were analyzed for microbiological count (Enterobacteriaceae, psychrophilic bacteria, mesophilic bacteria and pseudomonas bacteria) and chemical including pH, thiobarbituric acid reactive substances (TBARS), total volatile base nitrogen, peroxide value (POV) and free fatty acids (FFAs) and sensory (odor, color and texture) characteristics. Results showed that the highest levels of three factors including TBARS, POV and FFAs were related to the control sample and the least amount of these parameters was observed in EO and extract combination treatments. This effect of combined treatment was also observed in the reduction of total volatile basic nitrogen and pH parameters. Total bacterial counts during storage in fish treated with the extract and EO were remained below the acceptable level and microbial spoilage was significantly decreased compared to control. According to the sensory evaluation, treatments containing EO and extract showed improvement in this index compared to control treatment during storage. Based on the results of this study, it can be concluded that the EO and extract of P. affinis as active ingredients in zein coating successfully improve the quality and shelf life of the fish in the refrigerator.
Food Hygiene
Siavash Maktabi; Mehdi Zarei; Milad Chadorbaf
Volume 7, Issue 4 , December 2016, , Pages 295-300
Abstract
In recent years, there has been an increasing interest in using food additives from natural sources to improve taste and also extend the shelf-life of semi-preserved foodstuffs. The aim of this study was to examine the chemical and microbiological changes promoted by a local marinating process in rainbow ...
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In recent years, there has been an increasing interest in using food additives from natural sources to improve taste and also extend the shelf-life of semi-preserved foodstuffs. The aim of this study was to examine the chemical and microbiological changes promoted by a local marinating process in rainbow trout fillets during chilled storage. Fish fillets were immersed in marinades and stored at 4 ˚C for 10 days and were analyzed for total volatile basic nitrogen (TVN), thiobarbitoric acid (TBA), water holding capacity (WHC), pH, mesophilic and psychrophilic bacterial count every two days. Variations in TBA and WHC were not statistically significant between marinated and control groups. The values of TVN, pH, total psychrophilic bacteria count (TPC) and total mesophilic bacteria count (TMC) in marinated samples were significantly lower than controls. The most obvious finding of this study was that traditional marinated rainbow trout fillet stored in 4 ˚C had no undesirable changes at least for eight days.
Saeed Meshkini; Ali-Akbar Tafy; Amir Tukmechi; Farhad Farhang-Pajuh
Volume 3, Issue 1 , March 2012, , Pages 49-54
Abstract
The aim of our study was to evaluate the effects of chitosan as immune stimulator on some hematological parameters and stress resistance in rainbow trout. Nine hundred rainbow trout (with initial body weight of 25 ± 0.1 g) were obtained from a local farm and acclimated to the laboratory conditions ...
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The aim of our study was to evaluate the effects of chitosan as immune stimulator on some hematological parameters and stress resistance in rainbow trout. Nine hundred rainbow trout (with initial body weight of 25 ± 0.1 g) were obtained from a local farm and acclimated to the laboratory conditions for one week. After that fish were randomly divided into four groups in three replicates. Each group received chitosan in diet at four concentrations as 0 (Control), 0.25, 0.5 and 1 percent chitosan, respectively. The trial was conducted for 8 weeks then feeding with chitosan stopped for 3 weeks later and during this time all fish were feed by control diet. The sampling was conducted to assay the hematological parameters of all groups every two weeks. In this study we assayed the resistance of fish against some environmental stresses immediately after changing the diet to the control. The results showed that using 0.25 percent chitosan in trout diets had a significant effect (P < 0.05) on hematological indices and stress resistance of rainbow trout in comparison the control group. Serum glucose level was higher in all treatment than control without any significance difference (P < 0.05). Based on the obtained results it concluded that the adding chitosan at 0.25 percent into the diet could enhance the hematological parameters and resistance against some environmental stresses in rainbow trout.