scholarly journals Influence of dietary linseed and sunflower oil on sensory characteristics of rainbow trout (Oncorhynchus mykiss)

2011 ◽  
Vol 51 (No. 11) ◽  
pp. 475-482 ◽  
Author(s):  
Z. Drobná ◽  
J. Zelenka ◽  
E. Mrkvicová ◽  
D. Kladroba
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Sunflower Oil ◽  
Linseed Oil ◽  
Sensory Characteristics ◽  
Partial Replacement ◽  
Control Group ◽  
Fish Feed ◽  
Fish Fillet ◽  
Rainbow Trout Oncorhynchus Mykiss

This study describes the effects of dietary linseed and sunflower oil on the sensory characteristics of rainbow trout (Oncorhynchus mykiss) fillets. Rainbow trout were fed a diet containing either 2.5% or 5% of linseed or sunflower oil or 5% mixture of both oils (2.5% of each). Control group received a commercial feed mixture. A selected and trained panel carried out descriptive sensory tests on fish fillet cross-sections. The addition of vegetable oil into fish feed did not affect firmness, juiciness or intensity of total taste but had a significant impact on colour, intensity of odour and fish oily taste. A higher content of n-3 polyunsaturated fatty acids (PUFA) in linseed oil, in comparison with sunflower oil, is often responsible for the development of an off-flavour. No trout fillet was rejected owing to the off-flavour presence. Both concentrations of linseed oil decreased the intensity of fish oily taste. Therefore, for the partial replacement of fish oil in rainbow trout feed it is recommended the use linseed oil, which is a good source of n-3 PUFA.  

scholarly journals The Effect of Mycotoxin Deoxynivalenol on Haematological and Biochemical Indicators and Histopathological Changes in Rainbow Trout (Oncorhynchus mykiss)

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Iveta Matejova ◽  
Helena Modra ◽  
Jana Blahova ◽  
Ales Franc ◽  
Petr Fictum ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Histopathological Examination ◽  
Control Group ◽  
Fish Feed ◽  
Histopathological Changes ◽  
Biometric Parameters ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Commercial Feed ◽  
Biochemical Indices

Deoxynivalenol (DON), produced by theFusariumgenus, is a major contaminant of cereal grains used in the production of fish feed. The effect of mycotoxin deoxynivalenol on rainbow trout (Oncorhynchus mykiss) was studied using a commercial feed with the addition of DON in a dose of 2 mg/kg feed. The fish(n=40)were exposed to the mycotoxin for 23 days. The trout were divided into two groups, control and experimental groups. Control groups were fed a commercial feed naturally contaminated with a low concentration of DON (225 μg/kg feed); experimental groups were fed a commercial feed with the addition of DON (1964 μg/kg feed). Plasma biochemical and haematological indices, biometric parameters, and histopathological changes were assessed at the end of the experiment. The experimental groups showed significantly lower values in MCH(P<0.05). In biochemical indices, after 23-day exposure, a significant decrease in glucose, cholesterol(P<0.05), and ammonia(P<0.01)was recorded in the experimental group compared to the control group. Our assessment showed no significant changes in biometric parameters. The histopathological examination revealed disorders in the caudal kidney of the exposed fish. The obtained data show the sensitivity of rainbow trout (O. mykiss) to deoxynivalenol.

scholarly journals Evaluation of Yeast Biomass (Candida utilis) in a Practical Diet for Rainbow Trout (Oncorhynchus mykiss)

1999 ◽  
Vol 4 (1) ◽  
pp. 47
Author(s):  
J.S. Goddard ◽  
G. Deveau ◽  
A.M. Martin
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Crude Protein ◽  
Candida Utilis ◽  
Fish Meal ◽  
Partial Replacement ◽  
Peat Moss ◽  
Control Group ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Yeast Biomass

A yeast, Candida utilis, cultured on a substrate derived from a mixture of peat moss and fish processing waste, was substituted for fish meal in a practical diet for rainbow trout, Oncorhynchus mykiss. The formulated diets were isonitrogenous (40% crude protein) and isoealoric (gross energy 20 kJ per g dry matter). During a 50-day feeding trial fish tripled in weight, and there were no significant differences in the mean final weights of groups of fish fed diets in which 0%, 25% and 35% of fishmeal had been replaced by yeast biomass. Diets containing yeast were palatable, as determined by food intake, and were highly digestible for protein. Carcass analysis revealed that the fish fed with yeast biomass had slightly higher crude protein and ash contents, and lower lipid levels than those of the control group. Significant reductions were recorded in food conversion efficiency as the yeast content of the diets increased. The results indicate the potential for partial replacement of fish meal (between 25-35%) by Candida utilis biomass in feeds formulated for rainbow trout.

scholarly journals Apparent Digestibility of Macronutrients and Fatty Acids from Microalgae (Schizochytrium sp.) Fed to Rainbow Trout (Oncorhynchus mykiss): A Potential Candidate for Fish Oil Substitution

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 456
Author(s):  
Amélie Bélanger ◽  
Pallab K. Sarker ◽  
Dominique P. Bureau ◽  
Yvan Chouinard ◽  
Grant W. Vandenberg
Keyword(s):  
Fatty Acids ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Fish Oil ◽  
Nutrient Digestibility ◽  
Fish Feed ◽  
Potential Candidate ◽  
Apparent Digestibility ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Aquaculture Feed

Aquaculture feed formulation has recently turned its focus to reduce the reliance on marine-derived resources and utilise alternative feedstuffs, as an approach to improve the environmental sustainability of the aquaculture sector. The fish oil market is highly volatile, and availability of this commodity is continuously decreasing for use in aquaculture. Currently, a growing number of commercial efforts producing microalgae are providing omega 3-rich oil for sustainable aquaculture feed. This study was focused to determine the nutrient digestibility of a marine microalga, Schizochytrium spp., which is rich in docosahexaenoic acid (DHA) and long-chain polyunsaturated fatty acids (LC-PUFA), as a novel dietary lipid source that could be utilized effectively by rainbow trout (Oncorhynchus mykiss). A whole-cell Schizochytrium spp. biomass was used in the digestibility experiment at two different temperatures, 8 °C and 15 °C. No significant differences were detected between the two temperatures for the apparent digestibility coefficients (ADCs) of the dry matter (94.3 ± 4.9%), total lipids (85.8 ± 0.0%), crude proteins (89.5 ± 1.8%), energy (83.1 ± 1.7%) and fatty acids (85.8 ± 7.5%). The ADCs of the nutrients, energy, DHA and other fatty acids showed that Schizochytrium spp. is a high-quality candidate for fish oil substitution and supplement of LC-PUFA in fish feed with vegetable oils.

Effect of Dietary Ascorbate on the Concentration of Tissue Ascorbic Acid, Dehydroascorbic Acid, Ascorbic Sulfate, and Activity of Ascorbic Sulfate Sulfohydrolase in Rainbow Trout (Oncorhynchus mykiss)

1990 ◽  
Vol 47 (8) ◽  
pp. 1518-1525 ◽  
Author(s):  
Konrad Dabrowski ◽  
Reinhard Lackner ◽  
Cristine Doblander
Keyword(s):  
Ascorbic Acid ◽  
Rainbow Trout ◽  
Vitamin C ◽  
Oncorhynchus Mykiss ◽  
Dehydroascorbic Acid ◽  
Control Group ◽  
High Demand ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Dietary Treatments ◽  
Kidney Liver

The concentrations of ascorbic acid in several tissues of rainbow trout (Oncorhynchus mykiss) are significantly influenced by various dietary treatments. Ascorbic acid was taken up readily by erythrocytes, kidney, liver, intestine, spleen, and brain in fish fed an ascorbate supplemented diet (AA group), the concentration being from 1.5 to 14.8-fold higher than in fish fed a diet lacking ascorbate (control group). In fish fed a diet supplemented with an equimolar amount of ascorbic acid in the form of ascorbic sulfate (AS group) the ascorbic acid concentrations in kidney, intestine, and erythrocytes were significantly elevated above those of the control group. Ascorbic sulfate was found in kidney, liver, and intestine of the AS group, but not in other groups. In fish fed a diet devoid of vitamin C the ascorbic acid concentrations in kidney, liver, intestine, and spleen were signficantly lower than in fasting fish over the same period of time (28 d), suggesting a high demand for vitamin C in an actively feeding animal. Salmonid fish are therefore probably unable to utilize ascorbic sulfate sufficiently to prevent the appearance of vitamin C deficiency, and thus resemble scurvy-prone mammals in this respect.

scholarly journals Immune Response of Rainbow Trout (Oncorhynchus mykiss) to Selected Antigens of Yersinia ruckeri

2009 ◽  
Vol 78 (1) ◽  
pp. 145-150 ◽  
Author(s):  
Unal Ispir ◽  
H. Bayram Gokhan ◽  
Mikail Ozcan ◽  
Mustafa Dorucu ◽  
Naim Saglam
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Metabolic Activity ◽  
Control Fish ◽  
Phagocytic Index ◽  
Control Group ◽  
Yersinia Ruckeri ◽  
Whole Cells ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Fish Group

In this study, effects of Yersinia ruckeri antigens on the immune mechanisms of rainbow trout (Oncorhynchus mykiss) were examined. The weight of the 120 fish used in this study was 20–30 g. After injecting 1 mg of formalin-inactivated whole cells (FKC) and O-antigen (Ag-O) intraperitoneally, blood was taken from the caudal vein of anaesthetized fish and metabolic activity of leukocytes (Nitroblue tetrazolium (NBT) activities), phagocytic activity (PA), phagocytic index (PI), serum protein and serum total immunoglobulin (TIg) levels were determined on day 30 after the first immunization. The same procedure was conducted in the control group. In all the experimental groups, considerable increases in the immune indicators were found and significant differences detected between the control and experimental groups (p < 0.05). Metabolic activity of leukocytes decreased significantly (p < 0.05) during the following treatment with antigens compared to the control fish group.

Effect of animal and vegetal protein diets on feed intake and apparent digestibility of nutrients in rainbow trout (Oncorhynchus mykiss) infected by Aeromonas salmonicida, with and without chronic hypoxia stress

1998 ◽  
Vol 55 (9) ◽  
pp. 2019-2027 ◽  
Author(s):  
H Néji ◽  
J de la Noüe
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Feed Intake ◽  
Chronic Hypoxia ◽  
Phosphate Buffer Solution ◽  
Aeromonas Salmonicida ◽  
Animal Protein ◽  
Fish Feed ◽  
Apparent Digestibility ◽  
Rainbow Trout Oncorhynchus Mykiss

This study was undertaken to investigate the effects of bacterial infection (Aeromonas salmonicida) and chronic hypoxia on mortality, feed intake, and apparent digestibility of each of two diets in rainbow trout (Oncorhynchus mykiss). The diets were isonitrogenous (gross basis); one was based mainly on animal protein and the other on vegetal protein. In each of two separate and successive experiments, where the first served as a control for the second, fish were immersed on day 0 (d0) in either a sterile phosphate buffer solution (first experiment) or a suspension of A. salmonicida (second experiment). Thereafter, the fish were either exposed on d2 for 12 days to hypoxic conditions (60% of water oxygen saturation) or maintained under normal conditions. Feed intake was measured daily, while apparent digestibility coefficients for gross energy, dry matter, and crude protein were measured on d0, d2, d5, d9, d11, and d14. Among all infected fish, feed intakes were reduced (P < 0.05), regardless of the source of dietary protein or the degree of water oxygenation. Also, regardless of infection, the feed intakes of hypoxic fish that were fed the vegetal protein based diet were significantly less than those of fish that were fed the animal protein based diet. This response, however, was transitory, since normal levels of feed intake in the former fish were found by d3. The apparent digestibility coefficients for all parameters were unaltered by hypoxia (P > 0.05), but they were significantly reduced (P < 0.05) by A. salmonicida infection, especially during the critical period of infection (d5 and d9).

scholarly journals Antioxidant responses and plasma biochemical characteristics in the freshwater rainbow trout, Oncorhynchus mykiss, after acute exposure to the fungicide propiconazole

2011 ◽  
Vol 56 (No. 2) ◽  
pp. 61-69 ◽  
Author(s):  
Z.-H. Li ◽  
V. Zlabek ◽  
J. Velíšek ◽  
R. Grabic ◽  
J. Machová ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Control Group ◽  
Antioxidant Responses ◽  
Stress Indices ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Plasma Enzymes ◽  
Plasma Characteristics ◽  
The Brain

In this study, the toxic effects of PCZ, a triazole fungicide present in aquatic environment, were studied in rainbow trout, Oncorhynchus mykiss, by an acute toxicity test. Compared to the control group, fish exposed to PCZ (96-h-LC50, 5.04 mg/l) showed significantly higher (P &lt; 0.05) plasma NH3 and GLU concentration and the activities of plasma enzymes including CK, ALT, AST, LDH, but the TP content was not significantly different (P &gt; 0.05). The oxidative stress indices (levels of LPO and CP) of brain and muscle in the experimental group were higher compared to the control group, especially for a significant change (P &lt; 0.05) in the brain. SOD, CAT, GPx and GR activity in the brain of experimental groups was significantly lower (P &lt; 0.05), however, an opposite tendency was found out in muscle. In addition, there are significant correlations between TBARS and CAT, TBARS and GPx, CP, and CAT, GR, and GPx in the fish brain. Thus, PCZ exposure changed the oxidative stress indices and plasma characteristics, and these changes may be used as potential bioindicators of the exposure and effect of PCZ in the controlled experiment. The use in monitoring of PCZ exposure under natural field conditions is possible, but it needs further investigations.

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