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Hans J. Rosenfeld Ragnar T. Samuelsen Per Lea 《The Journal of Horticultural Science and Biotechnology》2013,88(5):578-588
SummaryCarrots of cv. Panther F1 were grown in climate chambers at 9, 12, 15, 18 and 21°C, constant diurnal temperatures at three different periods of the year. The effect of varying solar radiation and temperatures were evaluated on growth, sensory attributes and chemical composition. Higher levels of light significantly increased most chemical and physical variables of the carrot roots. Temperature was the most important factor determining the variation in sensory and chemical variables, whereas for morphological features like root weight, root length and diameter measurements, light was more important than temperature. Principal component analysis (PCA) of chemical and physical variables explained 85% of the total variation by the first three principal components, the first component (PCI) being defined by physical variables, explained 46% of the variation, while the temperature related PC2 explained 32% of the variation. Prediction of sensory variables by chemical or physical variables by means of partial least square (PLS) was higher at low light intensity than at high light intensity. 相似文献
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Sten Ivar Siikavuopio Philip James Atle Mortensen Tor Andreas Samuelsen Trine Dale 《Aquaculture Research》2012,43(10):1515-1519
Groups of juvenile green sea urchin, Strongylocentrotus droebachiensis (average wet weight = 3.3 g), were fed five different dry feed rations (0.2%, 0.4%, 0.8%, 1.2% and 2.4% of their body weight per week) under constant light and temperature conditions for 160 days (Experiment I) in groups to examine growth effects, and for 40 days as individual treatments (Experiment II) to examine feeding efficiency. There was 100% survival of the sea urchins during both experiments. In Experiment I, the lowest ration group (0.2%) had significantly lower growth than the rest of the groups. There was no significant differences in growth between the sea urchin fed ration over 0.4% dry feed of the body wet weight per week. In Experiment II, the lowest feed ration groups (0.2%) had significant lowest growth but had the best feed conversion ratio (FCR), using 0.5 g of feed of dry feed per gram of sea urchin wet weight body growth. The FCR increased with increasing feed ration and the 2.4% group had the poorest FCR, using 1.3 g of feed per gram weight gain. Results from Experiments I and II illustrate that juvenile green sea urchin can grow at a restricted feed ration that is under maximum feed intake, without reduction in growth. 相似文献
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Inger Hilde Zahl Anders Kiessling Ole Bent Samuelsen Magne Kjerulf Hansen 《Aquaculture (Amsterdam, Netherlands)》2009,295(1-2):52-59
The efficacy of the anaesthetic agents benzocaine, metacaine (MS-222), metomidate and 2-phenoxyethanol was studied in Atlantic cod (Gadus morhua) with average body weights of 10 ± 4 g, 99 ± 33 g and 1022 ± 274 g at water temperatures of 8 °C and 16 °C. The agents were tested individually and as combination anaesthesia comprising pre-anaesthetic sedation with a low dosage of metomidate or 2-phenoxyethanol followed by anaesthesia with benzocaine or MS-222. All agents were administered through bath immersion with an exposure time of 5 min. The different treatments resulted in average induction and recovery times ranging from 52 ± 6 s to 182 ± 16 s and 77 ± 26 s to 659 ± 46 s respectively. Induction and recovery times varied in relation to water temperature and were generally shorter at 16 °C for all weight groups and treatments compared to 8 °C. For benzocaine and MS-222 induction and recovery times were found to increase with increasing body weight. For metomidate the recovery time increased with increasing weight whereas there were no weight related differences in induction time. No differences in either induction or recovery times associated to body weight were found for 2-phenoxyethanol. Acute stress prior to anaesthesia with MS-222 resulted in significantly shorter induction time and prolonged recovery time, as well as deeper anaesthetised fish. The dosage of MS-222 had to be reduced in order to avoid mortality in fish subjected to acute stress. Combination anaesthesia allowed a reduction of the dosages used for inducing anaesthesia and produced markedly reduced recovery times compared to agents administered individually. 相似文献
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The aim of this study was to investigate the impact of two types of fish raw material on fishmeal (FM) physicochemical properties, specific mechanical energy, starch gelatinization and physical feed quality. Eleven feed mixes based on six independent FMs from herring (FMH) and five from sand eel (FMSE) were extruded according to standardized conditions. Type of fish raw material influenced FM physicochemical properties and had significant impact on starch gelatinization and pellet hardness. Multivariate models were established based on partial least squares regression (R2 = 0.637–0.999). Improved degree of starch gelatinization was associated with increased degree of protein hydrolysis (P = 0.011) and by replacement of FMH with FMSE in the feed mix (P = 0.012). A large span in pellet hardness was observed (4.9–94.1 N). Improved hardness was associated with decreased level of non‐soluble protein (P < 0.001) and by replacement of FMSE with FMH (P < 0.001). For FMSE, improved hardness was associated with decreased level of non‐soluble protein (P < 0.001) and increased degree of protein hydrolysis (P = 0.002), compressed bulk density (P = 0.039) and dust fraction (P = 0.001). The underlying physical and chemical mechanisms are discussed. The study documents differences in technical quality of FM produced from herring and sand eel with significant impact on fish feed extrusion and pellet quality. 相似文献
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Water‐soluble protein level in fishmeal affects extrusion behaviour,phase transitions and physical quality of feed
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The aim of this research was to investigate the effect of water‐soluble protein (WSP) as a plasticizer in the fish feed extrusion process and the impact on physical pellet quality. A three‐factor central composite design was used to study the influence of the variables WSP in the feed mix, and steam and water addition in the extruder. Regression models with r2 in the range of 0.862–0.976 (P < 0.001) were established for specific mechanical energy (SME), pellet hardness, cutting strength, sectional expansion index, length, bulk density, oil adsorption capacity and extrudate flow‐starting temperature (Tf). Addition of WSP had a positive effect on SME and improved the physical pellet quality, while moisture had the opposite effect. Expansion parameters showed a complex relationship and were influenced by all the studied process variables. Increase in WSP and moisture content had a comparable effect on Tf reduction. This opens up the possibility to obtain a satisfactory ‘cook’ at reduced moisture level with a potential for significant reduction of the energy consumption during drying of the extrudate. Overall conclusion from the experiment is that WSP can be used as a processing aid for the fish feed industry, serving multiple purposes as nutrient, plasticizer and binder in extruded fish feed. 相似文献
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Ole Bent Samuelsen 《Aquaculture International》2006,14(5):443-450
The plasma, muscle and liver distribution and elimination of the antibacterial agent oxolinic acid were studied after multiple oral (p.o.) administration of 10 or 20 mg kg−1 day−1 to cod (Gadus morhua) for 6 days. The fish, held in seawater at 6 and 12°C and weighing 150–250 g were sampled 24 h following last medication. The concentrations in plasma and tissues were clearly dosage and temperature dependent. The distribution from plasma to muscle (muscle/plasma ratio) was higher than that from a single dose study and independent of temperature and dosage. The distribution from plasma to liver (liver/plasma ratio) was lower than the muscle/plasma ratio and according to this study dependent of the administered dosage but independent of temperature. The elimination of oxolinic acid from plasma, muscle and liver was considerably faster following multiple administration compared to a single administration. 相似文献
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The pharmacokinetic properties of the antibacterial agent oxolinic acid were studied after intravenous, intraperitoneal and oral administration to 1.5–3.0 kg Atlantic halibut, Hippoglossus hippoglossus L., held in sea water at 9 °C. Following intravenous injection, the plasma drug concentration-time profile showed two distinct phases. The terminal elimination half-life was estimated to be 52 h, whereas total body clearance (ClT) was determined to be 0.044 L kg–1 h–1. The volume of distribution at steady state, Vd(ss), was calculated to be 3.0 L kg–1, indicating good tissue penetration of oxolinic acid in Atlantic halibut. The peak plasma concentration (Cmax) and the time to peak plasma concentration (Tmax) were estimated to be 1.2 and 2.7 μg mL–1, and 21.5 and 80 h, respectively, following oral administration of medicated feed or intraperitoneal injection. The corresponding bioavailabilities were calculated to be 15% and 92%, respectively. Oral administration of vetoquinol, the carbitol ester of oxolinic acid, increased the bioavailability of oxolinic acid to 64% and the total bioavailability (oxolinic acid + vetoquinol) to 82%, whereas Cmax and Tmax values of 6.7 μg mL–1 and 14.5 h, respectively, for oxolinic acid, and 1.0 μg mL–1 and 6.3 h, respectively, for vetoquinol were obtained. Based on a minimum inhibitory concentration (MIC) of 0.0625 μg mL–1 for susceptible strains, a single intraperitoneal injection of 25 mg kg–1 of oxolinic acid maintains plasma levels in excess of 0.25 μg mL–1, corresponding to four times the MIC value, for ≈12 days. The corresponding values for a single oral dose of 25 mg kg–1 of oxolinic acid and vetoquinol were 5 and 10 days, respectively. For resistant strains with a MIC of 1 μg mL–1, a single oral dose of vetoquinol (25 mg kg–1) maintained plasma levels in excess of 4 μg mL–1 for 34 h. 相似文献
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Inger Hilde Zahl Anders Kiessling Ole Bent Samuelsen Rolf Erik Olsen 《Fish physiology and biochemistry》2010,36(3):719-730
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. 相似文献