| 1. |
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| 2. |
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| 3. |
- Abro, Rani, et al.
(författare)
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Evaluation of chitinolytic activities and membrane integrity in gut tissues of Arctic charr (Salvelinus alpinus) fed fish meal and zygomycete biomass.
- 2014
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Ingår i: Comparative Biochemistry and Physiology - Part B: Biochemistry & Molecular Biology. - : Elsevier BV. - 1096-4959 .- 1879-1107. ; 175, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Chitinolytic activity, nutrient uptake and intestinal barrier functions were investigated in gut tissues of Arctic charr (Salvelinus alpinus) fed iso-nitrogenous diets based on fish meal, with or without inclusion of zygomycetes (Rhizopus oryzae). We found that gut tissue of Arctic charr had significant chitinase activity, of both endo- and exo-chitinase iso-forms. Moreover, the distribution pattern along the GI tract of Arctic charr differed between endo-chitinase and exo-chitinase. The endo-chitinase activity in stomach tissue and in the distal intestine was several hundred-fold higher than the exo-chitinase activity in stomach tissue. The greatest exo-chitinase activity was found in the distal intestine. The zygomycete-based diet resulted in higher chitinolytic activity in gut tissue compared to the fish meal-based diet. Disturbed intestinal integrity and increased uptake rate of the amino acid lysine were observed in the distal, but not proximal, intestine of fish fed the zygomycete-based feed.
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| 4. |
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| 5. |
- Bankefors, Johan, et al.
(författare)
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A comparison of the metabolic profile on intact tissue and extracts of muscle and liver of juvenile Atlantic salmon (Salmo salar L.) - Application to a short feeding study
- 2011
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Ingår i: Food Chemistry. - : Elsevier BV. - 0308-8146 .- 1873-7072. ; 129, s. 1397-1405
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Tidskriftsartikel (refereegranskat)abstract
- The metabolite profiles from muscles and livers of Atlantic salmon were investigated using high resolution nuclear magnetic resonance (HR-NMR) spectroscopy of aqueous extracts and magic angle spinning (MAS) NMR spectroscopy of intact tissues. Comparison of the data showed that most small metabolites present in the aqueous extracts were also identified in the Carr-Purcell-Meiboom-Gill (CPMG) MAS NMR spectra of the intact tissues. Not only the total omega-3 fatty acid content, but also the EPA and DHA content, in the muscle and liver tissues could be calculated directly from the diffusion-edited MAS NMR spectra without the need for lipophilic extraction. The effect of replacing a normal fish meal during a period of 3 months with a diet containing 20% zygomycete was also investigated by multivariate analysis of the NMR spectra. Principal component analysis (PCA) was used to study the small metabolites distribution in the aqueous extracts of liver and muscles, and revealed that the feed containing zygomycete could have an influence on the metabolites profiles of juvenile Atlantic salmon. (C) 2011 Elsevier Ltd. All rights reserved.
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| 6. |
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| 7. |
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| 8. |
- Gräns, Albin, 1979, et al.
(författare)
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Post-Surgical Analgesia in Rainbow Trout: Is Reduced Cardioventilatory Activity a Sign of Improved Animal Welfare or the Adverse Effects of an Opioid Drug? : Effects of Post-Operative Analgesia in Fish
- 2014
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:4
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Tidskriftsartikel (refereegranskat)abstract
- The use of fish models in biomedical research is increasing. Since behavioural and physiological consequences of surgical procedures may affect experimental results, these effects should be defined and, if possible, ameliorated. Thus, the use of post-surgical analgesia should be considered after invasive procedures also in fish, but presently, little information exists on the effects of analgesics in fish. This study assessed the effects of an opioid drug, buprenorphine (0.05 mg/kg IM), on resting ventilation and heart rates during 7 days of postsurgical recovery in rainbow trout (Oncorhynchus mykiss) at 10°C by non-invasively recording bioelectric potentials from the fish via electrodes in the water. Baseline ventilation and heart rates were considerably lower compared to previously reported values for rainbow trout at 10°C, possibly due to the non-invasive recording technique. Buprenorphine significantly decreased both ventilation and heart rates further, and the effects were most pronounced at 4–7 days after anaesthesia, surgical procedures and administration of the drug. Somewhat surprisingly, the same effects of buprenorphine were seen in the two control groups that had not been subject to surgery. These results indicate that the reductions in ventilation and heart rates are not caused by an analgesic effect of the drug, but may instead reflect a general sedative effect acting on both behaviour as well as e.g. central control of ventilation in fishes. This resembles what has previously been demonstrated in mammals, although the duration of the drug effect is considerably longer in this ectothermic animal. Thus, before using buprenorphine for postoperative analgesic treatment in fish, these potentially adverse effects need further characterisation.
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| 9. |
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| 10. |
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| 11. |
- Kiessling, Anders
(författare)
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Anaesthesia of Atlantic halibut (Hippoglossus hippoglossus) - Effect of pre-anaesthetic sedation, and importance of body weight and water temperature
- 2011
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Ingår i: Aquaculture Research. - : Hindawi Limited. - 1355-557X .- 1365-2109. ; 42, s. 1235-1245
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Tidskriftsartikel (refereegranskat)abstract
- The efficacy of the anaesthetic agents benzocaine, metacaine (MS-222), metomidate, 2-phenoxyethanol, quinaldine and isoeugenol was studied in Atlantic halibut (Hippoglossus hippoglossus). Fish with an average body weight of 33 g were anaesthetized at 8 degrees C and fish with an average body weight of 1243 g were anaesthetized at 8 and 15 degrees C. Agents were tested individually and as combination anaesthesia comprising pre-anaesthetic sedation, followed by anaesthesia. Induction and recovery times varied in relation to the body weight and water temperature. Large fish had longer induction times and shorter recovery times, and displayed reduced responsiveness to handling compared with small fish. A higher temperature resulted in shorter induction times, longer recovery times and increased responsiveness to handling. Lower dosages were used for all agents in combination anaesthesia. In small fish, this had no effect on the induction times but resulted in shorter recovery times and reduced responsiveness to handling. In large fish, combination anaesthesia resulted in shorter induction times whereas no uniform trend in recovery times and no differences in responsiveness to handling were observed. Neither individual agents nor combinations blocked all reflex reactions to external stimulation in all fish of any treatment group. MS-222 and benzocaine, used separately or in combination anaesthesia, were the most effective agents in reducing reflex reactions.
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| 12. |
- Kiessling, Anders
(författare)
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Anaesthesia of farmed fish: implications for welfare
- 2012
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Ingår i: Fish Physiology and Biochemistry. - : Springer Science and Business Media LLC. - 0920-1742 .- 1573-5168. ; 38, s. 201-218
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Tidskriftsartikel (refereegranskat)abstract
- The analgesic effects of currently used agents, in spite of their proven local effects, are currently being debated as the agents are administrated to fish via inhalation rather than locally at the target site. We therefore recommend that all protocols of procedures requiring general anaesthesia should be complemented by administration of agents with analgesic effect at the site of tissue trauma.
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| 13. |
- Kiessling, Anders
(författare)
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Anesthesia induces stress in Atlantic salmon (Salmo salar), Atlantic cod (Gadus morhua) and Atlantic halibut (Hippoglossus hippoglossus)
- 2010
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Ingår i: Fish Physiology and Biochemistry. - : Springer Science and Business Media LLC. - 0920-1742 .- 1573-5168. ; 36, s. 719-730
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Tidskriftsartikel (refereegranskat)abstract
- Stress in response to anesthesia with benzocaine, MS-222, metomidate and isoeugenol was studied in Atlantic salmon (Salmo salar), Atlantic halibut (Hippoglossus hippoglossus), and Atlantic cod (Gadus morhua) with no concomitant stress from handling or confinement in association with anesthesia or sampling. All of the anesthetics tested induced a stress response in all species, displayed by a release of cortisol to the water. MS-222 anesthesia elicited the highest cortisol release rates, reaching maximum levels 0.5 h post-exposure and returning to basal levels after 3-4 h. Benzocaine anesthesia caused a bimodal response where the initial peak in cortisol release rate was followed by a second increase lasting towards the end of the trial (6 h). This bimodality was more profound in Atlantic salmon than in Atlantic halibut and Atlantic cod. Metomidate anesthesia induced the lowest release of cortisol of the agents tested in both Atlantic halibut and Atlantic cod, but resulted in a bimodal response in Atlantic salmon where the initial increase in cortisol release was followed by a larger increase peaking at 2-2.5 h post exposure before returning to basal levels after 5 h. The stress induced in Atlantic salmon by isoeugenol anesthesia resembled that of MS-222, but did not reach the same elevated level. Overall, the cortisol release was most profound in Atlantic salmon followed by Atlantic halibut and Atlantic cod.
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| 14. |
- Kiessling, Anders
(författare)
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Closing the nutrient loop, a key factor to sustainable aquaculture
- 2011
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Closing the nutrient loop, a key factor to sustainable aquaculture.Anders K. Kiessling Department of Wild Life, Fisheries and Environment, Swedish University of Agricultural Sciences, 901 83 Umeå, Sweden (SLU). Abstract In open systems feed is both the single largest cost to the farmer and the major factor affecting the environmental impact of fish farming, including production and transport of the feed as well as effluence from the farm during production. The main difference from terrestrial intensive animal production is that fish is farmed in water where recapture of dissolved nutrients are very difficult. RAS technology has the ability of equalising the problem between terrestrial and aquatic production. The two major issues terrestrial animal production, beyond local environment effects and high input of non-renewable energy, is the use of human grade food resources and secondly the loss of nutrients out of the food production system. Present RAS systems share both these problems with terrestrial animal production as well as the issue of non-renewable energy resources but it is reducing the problem of local impact. In order to make RAS production truly sustainable all these issues, including profitability and animal ethics, must be addressed. This presentation focuses the issue of feed resources competing with human food resources and the loss of nutrients out of the food production system as well as some of the problems specific for aquatic systems these issues impose. Keywords: Sustainable; Recycling; New feed sources * E-mail address: anders.kiessling@slu.se
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| 15. |
- Kiessling, Anders
(författare)
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Effect of nutritional status and sampling intensity on recovery after dorsal aorta cannulation in free-swimming Atlantic salmon (Salmo salar L.)
- 2012
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Ingår i: Fish Physiology and Biochemistry. - : Springer Science and Business Media LLC. - 0920-1742 .- 1573-5168. ; 38, s. 259-272
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Tidskriftsartikel (refereegranskat)abstract
- Recovery from implantation of a cannula in the dorsal aorta (DA) of Atlantic salmon (Salmo salar) was studied in relation to nutritional status and sampling intensity. The incentive for the study was the inconsistency between published reports and our own experience of recovery and longevity of fish exposed to this protocol. In two studies using starved fish, blood (0.3 ml) was sampled 0, 1 and 24 h after DA-cannulation, and thereafter at 48 and 72 h and thereafter once weekly for four weeks. In a third study using fed fish, four consecutive samples (0, 3, 6 and 12 h after ameal) were obtained twice a week over a four-week period. All fish displayed a sharp increase in pCO(2) and haematocrit (Hct) during surgery, followed by a marked raise in cortisol, glucose, sodium and potassium (1 h). pCO(2), pH and Hct approached baseline levels as early as the 1 h post-surgery sample, while this was not the case for cortisol and electrolytes before the 24 h post-surgery sample. Glucose did not display any significant changes post surgery. From then on, all variables displayed minor but non-significant (P > 0.05) changes indicating a steady state close to baseline values for unstressed fish. This pattern was independent of sampling procedure, i.e. repeated single or multiple samples and thus volume of blood removed. Nutritional status (fed vs. starved) did not affect post-surgical recovery pattern. Only K+ and Hct displayed consistent and significant post-prandial patterns. We found marked differences between baseline level of cannulated fish and uncannulated control fish, in pH, K+ and Hct indicating that cannulation may be the preferred method to obtain representative resting values in fish.
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| 16. |
- Kiessling, Anders, et al.
(författare)
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Feeding turbot based on ingredients from the Baltic Sea region: Comparative study with conventional feed ingredients
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The European aquaculture industry still depends on imported raw materials like fish meal and soy bean meal from overseas for fish feeds. To evaluate the potential of regional feed ingredients for nutrition of the carnivorous turbot (Psetta maxima) a long-term study was conducted to compare conventional and regionally sourced feed ingredients with regards to growth perfor-mance, health and filet quality of fish. One conventional diet (FM30) containing 30% fish meal and 20% soy bean meal and two diets, in which both ingredients were partly (FM15) or totally (FM0) substituted by regionally originated mussel meal, rapeseed protein concentrate and yeast were produced. In total 1476 juvenile turbot (21.6 g) were allocated in triplicates in a recirculating aquaculture system and fed daily for 292 days until apparent satiation. Results showed that comparable growth rates could be achieved in fish fed completely regionally sourced diets (FM0) in com-parison with conventional fish and soy based diets (FM30). However, best growth performance was observed in fish fed a mix of all test ingredients (FM15), where a similar feed conversion ratio (FCR) but an increased daily feed intake (DFI) in compari-son with FM30 was observed. The FCR decreased in group FM0 and the DFI increased in both diets FM0 and FM15 in com-parison with FM30. Furthermore hepatosomatic index (HSI) was highest and protein efficiency ratio (PER) lowest in treatment FM0. No significant differences were observed in-between dietary treatments with regards to other investigated physiological parameters and health status of fish such as splenic index, haematocrit and mortality. Furthermore in the sensory panel no significant differences in filet quality were observed between group FM30, FM15 and FM0. It was concluded that turbot can be grown entirely based on regional ingredients without adverse effects on growth perfor-mance, health and product quality of fish. However, in future slightly reduced performance of fish fed regionally originated feed source could be overcome by optimized processings and thereby improved nutritive characteristics.
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| 17. |
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| 18. |
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| 19. |
- Kiessling, Anders
(författare)
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Vattenbruk i Sverige - då och nu
- 2013
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Ingår i: Havsbruk som håller i längden. - 9789154060740 ; , s. 247-256
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 20. |
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| 21. |
- Kiessling, Jonas, 1980-
(författare)
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Approximation and Calibration of Stochastic Processes in Finance
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is a study of approximation and calibration of stochastic processes with applications in finance. It consists of an introduction and four research papers. The introduction is as an overview of the role of mathematics incertain areas of finance. It contains a brief introduction to the mathematicaltheory of option pricing, as well as a description of a mathematicalmodel of a financial exchange. The introduction also includessummaries of the four research papers. In Paper I, Markov decision theory is applied to design algorithmic trading strategies in an order driven market. A high dimensional Markov chain is used to model the state and evolution of the limit order book. Trading strategies are formulated as optimal decision problems. Conditions that guarantee existence of optimal strategies are provided, as well as a value-iterative algorithm that enables numerical construction of optimal strategies. The results are illustrated with numerical experiments on high frequency data from a foreign exchange market. Paper II focuses on asset pricing with Lévy processes. The expected value E[g(XT )] is estimated using a Monte Carlo method, when Xt is a d-dimensional Lévy process having infinite jump activity and a smooth density. Approximating jumps smaller then a parameter ε > 0 by diffusion results in a weak approximation, Xt, of Xt. The main result of the paper is an estimate of the resulting model error E[g(XT )] − E[g(T )], with a computable leading order term. Option prices in exponential Lévy models solve certain partia lintegro-differential equations (PIDEs). A finite difference scheme suitable for solving such PIDEs is studied in Paper III. The main resultsare estimates of the time and space discretization errors, with leading order terms in computable form. If the underlying Lévy process has infinite jump activity, the jumps smaller than some ε > 0 are replacedby diffusion. The size of this diffusion approximation is estimated, as well as its effect on the space and time discretization errors. Combined, the results of the paper are enough to determine how to jointly choose the grid size and the parameter ε. In Paper IV it is demonstrated how optimal control can be used to calibrate a jump-diffusion process to quoted option prices. The calibration problem is formulated as an optimal control problem with the model parameter as a control variable. The corresponding regularized Hamiltonian system is solved with a symplectic Euler method.
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| 22. |
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| 23. |
- Lundh, Torbjörn, et al.
(författare)
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Nutrient digestibility and growth in Arctic charr fed microbial and mussel protein meal
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The content of marine based feed sources must be decreased in feed for fish. New production has to be built on sustainable practices and technologies which include production of aquafeeds with other ingredients which are not suitable as food for humans. We have investigated the nutrient digestibility and performed a short term growth study on Artic charr fed microbial biomass and blue mussel meal instead of fish meal. Analysis of feed show dif- ferent amino acid profiles with very low methionine content in especially R. oryaze (RHO) and extracted Saccha- romyces (ESC), whereas intact Saccharomyces (ISC) showed similar amino acid profile as fish meal but with slightly lower methionine content. The apparent digestibility coefficients of dry matter, crude protein, total amino acid and energy were highest for ESC, mussel meal (MYE) and RHO. No difference in weight gain was observed between fish fed the reference diet, diet ISC and diet MYE. Fish fed diet RHO and ESC showed 16 and 13% lower weight gain compared with fish fed diet REF. The conclusion of the results is that intact Saccharomyces and mussel meal are good alternatives as a protein source instead of marine fish meal for feeding Arctic charr. The results suggest that ISC togheter with MYE is the best choice for developing locally produced feed resources and closing the nutrient loop in the Baltic Sea region. The results will be followed up with further evaluation in long-term feeding experiments with Arctic charr
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| 24. |
- Olstorpe, Matilda, et al.
(författare)
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Strain-and temperature-dependent changes of fatty acid composition in Wickerhamomyces anomalus and Blastobotrys adeninivorans
- 2014
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Ingår i: Biotechnology and Applied Biochemistry. - : Wiley. - 0885-4513 .- 1470-8744. ; 61, s. 45-50
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Tidskriftsartikel (refereegranskat)abstract
- The fatty acid (FA) profiles of two strains of the yeasts Wickerhamomyces anomalus and Blastobotrys (Arxula) adeninivorans at cultivation temperatures from 15 to 30 degrees C were characterized. Besides the common even-numbered C16 and C18 FAs, substantial proportions of the uneven-numbered C17:1 were found in both species. C18:3(n-3) (alpha linolenic acid) made up to 3% of the total FAs in all strains. Considerable strain differences occurred, with regard to both the presence of single FAs and parameters like the double binding index (DBI) and C16:C18 ratio. W. anomalus J121 formed C18:1(n-5) (up to 10.9% of the total FAs) but no C18:1(n-7), whereas in W. anomalusVKM160, no C18:1(n-5) was found but up to 14.6% C18:1(n-7). Similarly, B. adeninivoransCBS 8244 formed exclusively C18:1(n-7) (maximum 9%) and CBS 7377 C18:1(n-5) (maximum 12.6%). W. anomalus J121 had the lowest DBI (0.72) at 15 degrees C and the highest (0.92) at 20 degrees C, at which point the values decreased with increasing temperatures. In W. anomalusVKM160 and both B. adeninivorans strains, DBI was highest at 15 degrees C and decreased with increasing temperature. In J121, the C16:C18 ratio was highest at 15 degrees C, decreasing at higher temperatures, whereas in the other strains, the opposite trend was observed.
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| 25. |
- Sandblom, Erik, 1978, et al.
(författare)
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Effects of electric field exposure on blood pressure, cardioventilatory activity and the physiological stress response in Arctic char, Salvelinus alpinus L.
- 2012
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Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486 .- 1873-5622. ; 344-349, s. 135-140
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Tidskriftsartikel (refereegranskat)abstract
- Electric field exposure is used to stun or immobilize fish prior to slaughter in the aquaculture industry and for field sampling purposes (i.e. electrofishing), but the physiological response of fish to this exposure is incompletely understood. In this paper we report on changes in blood pressure, heart and ventilation rates, and hematological variables in chronically cannulated Arctic char (Salvelinus alpinus) in response to exposure to an electric field of 4 V/cm (125 Hz) for 5 and 30 s. Both durations of exposure resulted in a brief (total duration: 5.2 to 6.0 s, respectively) four-fold blood pressure increase above resting levels. The 5 s exposure was followed by a period of cardiac and ventilatory arrest (for 35 and 176 s on average, respectively), but cardioventilatory activity recovered in ten out of eleven fish. Nevertheless, signs of systemic stress responses were evident after the exposure. These included moderate hypertension, increased ventilation amplitude, increased plasma cortisol levels and altered hydromineral balance. After the 30 s exposure, cardiac activity initially appeared to recover, but subsequently declined. Ventilation did not recover. It is suggested that circulatory failure due to cardiac ischemia resulting from ventilatory failure; rather than instantaneous and irrecoverable cardiac arrest from the electric field exposure per se, is the ultimate cause of death in fish that fail to recover from exposure to an electric field in water. The brief dramatic hypertension observed in char may partly explain the haemorrhages that are frequently observed in electrically stunned fish of some species.
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| 26. |
- Sandblom, Erik, 1978, et al.
(författare)
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Stress responses in Arctic char (Salvelinus alpinus L.) during hyperoxic carbon dioxide immobilization relevant to aquaculture
- 2013
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Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486 .- 1873-5622. ; 414–415, s. 254-259
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Tidskriftsartikel (refereegranskat)abstract
- Physiological responses during immobilization with hyperoxic hypercapnia were determined in cannulated Arctic char (Salvelinus alpinus) exposed for 10 min to mixtures of 10% CO2 in 90% O2 (10:90) or 50% CO2 in 50% O2 (50:50). Results were compared with a previous study on the same group of char using pure CO2 under identical experimental conditions to test the hypothesis that supplemental oxygen may reduce stress and improve welfare during CO2 exposure. While all fish recovered from the two exposures, the time to loss of equilibrium with the 50:50 mixture was significantly shorter than for the 10:90 mixture (143 vs. 276 s); and the time to regain equilibrium was longer (2302 vs. 963 s). Hypertension and bradycardia developed with 10:90, while 50:50 resulted in tachycardia and unchanged blood pressure. Ventilation frequency and amplitude increased significantly with 10:90, whereas ventilation ceased completely with 50:50. Primary and secondary stress responses were evident during recovery in normoxia in both groups as indicated by elevated heart rate and ventilation and increased plasma cortisol. However, recovery appeared to be faster with the 10:90 mixture because ventilation amplitude and plasma cortisol levels declined more rapidly. Nonetheless, the times to loss of equilibrium recorded here with mixtures of oxygen and carbon dioxide bracket that observed previously with pure CO2. Furthermore, the increase in plasma cortisol was similar or higher in the present study suggesting that while supplemental oxygen does not markedly reduce stress or improve welfare during carbon dioxide immobilization, survival and recovery in normoxia are improved.
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| 27. |
- Seth, Henrik, 1979, et al.
(författare)
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Physiological responses and welfare implications of rapid hypothermia and immobilization with high levels of CO2 at two temperatures in Arctic char (Salvelinus alpinus).
- 2013
-
Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486 .- 1873-5622. ; 402-403, s. 146-151
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Tidskriftsartikel (refereegranskat)abstract
- Carbon dioxide (CO2) is used for immobilisation of Arctic char (Salvelinus alpinus) prior to slaughter at Swedish aquaculture facilities, and fish are routinely exposed to hypothermia in ice water during transport. Yet, information on stress physiological responses to CO2, temperature extremes and their potential interacting effects is scarce for this cold-water species. Here, blood pressure, heart and ventilation rates and plasma variables including ions, haematocrit, glucose and cortisol were measured in cannulated char during exposure to hypothermia (i.e. a rapid temperature drop from 10 °C to 0.25 °C); as well as to water nearly saturated with CO2 at 10 °C and 0.25 °C to test the hypothesis that hypothermia alleviates stress responses during CO2 exposure. While all fish maintained equilibrium during the 30 min hypothermic challenge, blood pressure, heart and ventilation rates decreased and plasma cortisol increased moderately. CO2 exposure at 10 and 0.25 °C resulted in aversive behavioural reactions before equilibrium was irrecoverably lost after 184 ± 14 and 191 ± 9 s, respectively. The physiological responses to CO2 exposure were largely similar at both temperatures with elevated cortisol levels, reduced heart and ventilation rates and hypotension; although reductions in ventilation amplitude and arterial pulse pressure were significantly more pronounced at 0.25 °C. It is concluded that hypothermia alone is a relatively mild stressor in this species, while CO2 exposure elicits pronounced physiological and behavioural stress responses that are not alleviated by hypothermia.
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| 28. |
- Trattner, Sofia, et al.
(författare)
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The effect of hepatic passage on postprandial plasma lipid profile of rainbow trout (Oncorhynchus mykiss) after a single meal
- 2010
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Ingår i: Aquaculture Nutrition. - : Hindawi Limited. - 1353-5773 .- 1365-2095. ; 16, s. 536-543
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Tidskriftsartikel (refereegranskat)abstract
- For the first time, pre- and post-hepatic plasma lipid profiles were monitored following a single meal in a free-swimming, non-anaesthetized fish. Rainbow trout (Oncorhynchus mykiss; 700-1500 g; 10 degrees C) were equipped with cannulae in the dorsal aorta (DA) and hepatic portal vein (HPV). Simultaneous blood samples, taken from both cannulae at 0, 3, 6, 12, 24 and 48 h postprandial, revealed the time course of the plasma lipid profiles following a single meal (1% of body mass). Primarily monounsaturated fatty acids with the exception of 18:1n - 9, increased significantly from baseline by 12 h postprandial without greatly affecting total plasma lipid concentrations. Total plasma lipids then showed a small peak at 24 h postprandial, coinciding with a peak in triacylglycerols. We conclude that assimilation of lipids from the digest into the plasma is slower than reported for proteins and carbohydrates in the same species. Furthermore, as there were no significant differences between the HPV and DA, no measurable effect of hepatic passage on plasma lipid levels was resolved. Therefore, we also conclude that, in contrast to that in higher vertebrates, hepatic passage does not seem to have a major role in rainbow trout for modulating the postprandial plasma profile of lipids.
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| 29. |
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| 30. |
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