Lund I.,Technical University of Denmark |
Dalsgaard J.,Technical University of Denmark |
Jacobsen C.,Technical University of Denmark |
Hansen J.H.,Innovation Center Denmark |
And 2 more authors.
Producing organic fish diets requires that the use of both fishmeal and fish oil (FO) be minimized and replaced by sustainable, organic sources. The purpose of the present study was to replace FO with organic oils and evaluate the effects on feed intake, feed conversion ratio (FCR), daily specific growth rate (SGR) and nutrient digestibility in diets in which fishmeal protein was partly substituted by organic plant protein concentrates. It is prohibited to add antioxidants to organic oils, and therefore the effects of force-oxidizing the oils (including FO) on feed intake and nutrient digestibility was furthermore examined. Four organic oils with either a relatively high or low content of polyunsaturated fatty acids were considered: linseed oil, rapeseed oil, sunflower oil and grapeseed oil. Substituting FO with organic oils did not affect feed intake (P > 0.05), FCR or SGR (P > 0.05) despite very different dietary fatty acid profiles. All organic plant oils had a positive effect on apparent lipid digestibility compared with the FO diet (P < 0.05), whereas there were no effects on the apparent digestibility of other macronutrients when compared with the FO diet (P > 0.05). Organic vegetable oils did not undergo auto-oxidation as opposed to the FO, and the FO diet consequently had a significantly negative effect on the apparent lipid digestibility. Feed intake was not affected by oxidation of any oils. In conclusion, the study demonstrated that it is possible to fully substitute FO with plant-based organic oils without negatively affecting nutrient digestibility and growth performance. Furthermore, plant-based organic oils are less likely to oxidize than FOs, prolonging the shelf life of such organic diets. © 2012 The Animal Consortium. Source
Berntssen M.H.G.,National Institute of Nutrition And Seafood Research |
Tollefsen K.-E.,Norwegian Institute for Water Research |
Tollefsen K.-E.,University of Life science |
Handy R.D.,University of Plymouth |
And 4 more authors.
Seawater adapted Atlantic salmon post-smolts were fed graded levels of technical endosulfan (0.005, 0.05, and 1 mg kg- 1) for 16 weeks. Markers of endocrine disruption (plasma vitellogenin, and plasma sex steroid-binding proteins) and oxidative stress (hepatic glutathione peroxidase activity, and α-tocopherol level) were not affected by dietary concentrations used in this study. Adaptive responses such as biotransformation (hepatic 7-ethoxyresorufin-O-deethylase EROD activity) was significantly induced at the lowest and second lowest exposure levels (0.005 and 0.05 mg kg- 1), but not at the highest exposure levels. Adverse effects such as significantly increased hepatic somatic index was observed in the 1 mg kg- 1 exposure group, however, apparent markers of liver damage (plasma aspartate aminotransferase and alanine aminotransferase level, or liver histopathological necrosis) were absent. The relative amount (%) of red pulp in spleen significantly increased in fish fed 0.005 and 0.05 mg kg- 1 whereas haematology (e.g. blood erythrocyte count and haemoglobin) remained similar to that of the control group. Levels of 0.005 and 0.05 mg kg- 1 did not cause overall adverse effects, whereas levels of 1 mg kg- 1 caused adverse effects as seen from a lacking hepatic biotransformation (EROD) activity and increased hepatic somatic index. Histological changes such as areas of vacuolization and fusion of villi in the intestine at lowest exposure levels warrant further investigation on the effects of dietary endosulfan exposure on nutritional performance and growth. © 2010 Elsevier B.V. All rights reserved. Source
Berntssen M.H.G.,National Institute of Nutrition And Seafood Research |
Ornsrud R.,National Institute of Nutrition And Seafood Research |
Rasinger J.,National Institute of Nutrition And Seafood Research |
Softeland L.,National Institute of Nutrition And Seafood Research |
And 7 more authors.
Several studies have reported on the interaction between vitamin A (VA) and aryl hydrocarbon receptor (AhR)-binding toxicants, including poly-aromatic hydrocarbons (PAHs). In aquaculture, the use of plant oils in novel aquafeeds can increase PAH levels while simultaneously lowering natural VA background levels, causing the need to supplement plant oil-based feeds with synthetic VA. To study dietary VA-PAH interactions, Atlantic salmon (initial weight 195 ± 0.15 g) were fed four identical plant-based diets that were supplemented with PAHs (100 and 10 mg kg-1 benzo[a]pyrene (BaP) and phenanthrene (Phe), respectively) or VA (retinyl acetate 8721 IU kg-1) separately or combined for 2.5 months in a 2 × 2 factorial design, with triplicate net-pens per diet. Dietary PAH significantly reduced hepatic VA storage, and VA-enriched diets restored hepatic VA. There was a significant PAH-VA interaction effect on hepatic BaP, but not Phe, accumulation, with reduced hepatic BaP concentrations in fish fed VA+PAH compared to fish fed PAH alone. Concurrently, PAH and VA significantly interacted in their effects on CYP1A phase I biotransformation as observed from increased ethoxyresorufin-O-deethylase (EROD) activity, increased CYP1A protein concentration, and elevated transcription (cyp1a1 gene expression) in fish fed PAH+VA compared to PAH alone. Dietary VA supplementation alone had no significant effect on CYP1A phase I biotransformation. Metabolomic assessment showed that dietary VA caused a restoration of metabolic intermediates involved in energy metabolism that were affected by dietary PAH. Moreover, a PAH-induced growth inhibition was partially ameliorated by dietary VA supplementation. In conclusion, dietary VA interacted with PAH toxicity on the level of CYP1A-mediated detoxification, hepatic PAH accumulation, energy allocation, and growth. © 2016 Elsevier B.V. Source
Lock E.-J.,National Institute of Nutrition And Seafood Research |
Fjelldal P.-G.,Norwegian Institute of Marine Research |
Torstensen B.E.,National Institute of Nutrition And Seafood Research |
Bjoslashrnevik M.,Bodoslash University College |
And 9 more authors.
Fish oil is the main contributor of persistent organic pollutants (POPs) in fish feed. A combination of active carbon filtration and steam deodourization can remove most of the POPs. However, other fat soluble compounds are also removed, thus possibly affecting the nutritional quality of decontaminated fish oils. Sea water-adapted Atlantic salmon were fed 18months a commercially relevant diet based on either decontaminated or non-treated fish oil until market size. The development of production-related diseases (fin/skin erosion, bone deformity, cataract) and fillet quality parameters (gutted weight, fillet fat soluble vitamin levels and fatty acid composition, colour, gaping, texture and sensory quality) were assessed. No significant differences in growth performances, feed conversion ratio or quality parameters between the two dietary groups were found. The fillet levels of fat soluble vitamins in market size fish remained unaltered, and only marginal differences were observed in fatty acid profiles. There was a significantly lower percentage of deformed vertebrae in the tail region of fish fed the decontaminated fish oil diets, indicating a positive effect of the use of decontaminated fish oil. No apparent negative effects of the use of decontaminated fish oil in Atlantic salmon diets were reported in this study. © 2011 NIFES. Source
Denstadli V.,Norwegian University of Life Sciences |
Bakke A.M.,Aquaculture Protein Center |
Krogdahl A.,Aquaculture Protein Center |
Hillestad M.,BioMar |
Holm H.,University of Oslo
Journal of Nutrition
An increasingly larger proportion of the oils used in diets for farmed fish are plant derived and rapeseed oil is most commonly used. Despite high dietary lipid levels and a marked change in lipid composition, the transport and metabolic fate of absorbed fatty acids is not fully understood in teleost fish. The main purpose of this study was to trace the postabsorptive metabolic fate of 2 fatty acids of different chain length: oleic acid [ 3H-18:1(n-9)], constituting 70% of fatty acids in rapeseed oil, and the medium-chain decanoic acid [ 14C-10:0], which does not require carrier molecules for membrane passage. The fatty acids and their metabolites were traced in portal and peripheral blood, liver, heart, skeletal muscle, and visceral adipose tissue at time intervals from 3 to 48 h after feeding. The portal vein was the primary transport route for both 10:0 and 18:1(n-9) from the intestine to the liver the first 6 h after feed intake. From 12 to 48 h, the peripheral route became increasingly more important. The study also indicates a possible direct transport route of fatty acids from the intestine to the surrounding viscera. Our data demonstrate that whereas 18:1(n-9) is primarily deposited as TG in skeletal muscle and visceral adipose tissue, 10:0 is used by the heart and skeletal muscle as a source for rapid energy production. © 2011 American Society for Nutrition. Source