• Fisheries and Aquatic Sciences
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• v.11 no.3
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• pp.125-132
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• 2008

The development of a fish that functionally provides both antioxidant and fat-reducing effects is an important goal in nutrition and aquaculture research. Dietary conjugated linoleic acid(CLA) can be successfully incorporated in fish muscle and viscera, but CLA and carotenoids have not been evaluated in such fish. An 8 weeks growth trial was conducted using rainbow trout, and all fish were fed twice daily with experimental diets containing graded amounts of CLA(1% and 5%). At the end of the experiment, the daily growth index, feed conversion rate, lipid class, and fatty acid composition were determined. Dietary CLA did not enhance the growth parameters of rainbow trout but did improve the feed conversion rate. The muscular polar lipid content decreased during the feeding period, while the content was stable in the viscera. In addition, a diet high in CLA decreased the polyunsaturated fatty acid content, but had no effect on the content of monounsaturated and saturated fatty acid in muscle.

• Journal of Aquaculture
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• v.9 no.3
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• pp.265-278
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• 1996

A long-term (160 days) feeding experiment was conducted to evaluate effects of dietary soybean meal (SBM) on growth of rainbow trout (Oncorhynchus mykiss). Fish fed diets containing up to $46\%$ of SBM showed the same growth rates with control during the first 60 days (p>0.05). However, growth showed a gradual decrease with the culture period. At the end of 160-days experiment, fish fed diets with above $34\%$ of SBM showed a decrease in growth rate compared to the control group. Fatness of experimental fish was reduced with an increase in dietary SBM levels and in feeding period. Hepatosomatic index was significantly lower from fish fed the diets containing above $46\%$ of SBM than that from fish fed the control diet throughout the 160 days of experimental period, and fish fed diet containing above $46\%$ of SBM appeared to make restricted utilization of carbohydrate sources. These results may suggest that soybean meal could be used up to $22\%$ in trout diet as a substitute for fish meal without unfavourable side effects.

• Journal of Life Science
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• v.13 no.1
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• pp.128-135
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• 2003

102 ESTs (Expressed Sequence Tags) were obtained by sequencing clones from a library of rainbow trout kidney cDNAs. Of the sequences generated, 55.8% of the ESTs were represented by 37 known genes. The 45 clones of unknown gene products potentially represent 40 novel genes. The genes involved in structural function (14.5%) and transcription/translation (11.6%) account for the major gene expression activities in the kidney Microarray experiment was conducted to compare gene expression of the unique ESTs in young and adult rainbow trout kidneys. While mitochondrion, cytochrome b, rho G, spastin protein, and three unknown genes were down-regulated in the mature fish kidney, calponin 1, calcium binding protein, histone deacetylase 1, and an unknown gene were up-regulated in the mature fish kidney. This research demonstrates the feasibility and power of functional genomics in rainbow trout.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.7
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• pp.974-981
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• 2011

This study was designed to re-evaluate the dietary methionine requirement by means of the plasma methionine and ammonia concentrations in surgically modified rainbow trout, Oncorhynchus mykiss. A total of 35 rainbow trout averaging $505{\pm}6.5$ g (initial body weight, mean${\pm}$SD) were randomly distributed into seven groups with five fish in each group. After 48 h of feed deprivation, each group of fish was fed one of seven L-amino acid based diets containing 0.5% cystine and graded levels of methionine (0.25, 0.40, 0.50, 0.60, 0.70, 0.80 or 0.95% of diet, dry matter bases) by intubation at 1% body weight on dry matter basis. Blood samples were taken at 0, 5 and 24 h after intubation. Post-prandial plasma free methionine concentrations (PPmet, 5 h after intubation) and post-absorptive plasma free methionine concentrations (PAmet, 24 h after intubation) of fish fed diets containing 0.60% or higher methionine were significantly (p<0.05) higher than those of fish fed diets containing 0.50% or lower methionine. PPmet and PAmet in fish fed diets containing 0.60% or higher methionine were not significantly different except PPmet of fish fed diet containing 0.95% methionine. Post-prandial plasma ammonia concentrations (PPA, 5 h after intubation) of fish fed diets containing 0.70% or higher methionine were significantly higher than those of fish fed diets containing 0.60% or lower methionine, and PPA of fish fed diets containing 0.25 and up to 0.60% methionine were not significantly different from each other. Broken-line model analyses on PPmet, PAmet, and PPA indicated that the dietary methionine requirement of rainbow trout was between 0.59 (1.69) and 0.67 (1.91) % of diets (% dietary protein bases) when the diets contained 0.5% cystine.

• Journal of fish pathology
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• v.16 no.3
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• pp.139-146
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• 2003

We have investigated the biological effects of recombinant IL-1$\beta$ (rIL-1$\beta$) on the expression of antiviral genes such as Myxovirus-3 (MX-3) and Interferon regulating factor-1 (IRF-1), which are related to type I interferon. When ten micrograms of rIL-1$\beta$ were treated, we observed the stimulatory effect on the expression of these antiviral genes. Interestingly, at the early stage of stimulation, these genes were down-regulated and then up-regulated by the results obtained that the expressions of these genes were decreased at day 1 post-injection and gradually increased at day 3 post-injection. Thus, the stimulatory effect of rIL-1$\beta$ on the expression of MX-3 and IRF-3 gene might be an indirect stimulatory effect because significant up-regulation was delayed until day 3 post-injection.

• Journal of Aquaculture
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• v.10 no.3
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• pp.347-356
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• 1997

Feeding experiment was conducted to evaluate effects of dietary soybean meal (SBM) on the phosphorus bioavailability of rainbow trout (Oncorhynchus mykiss). Seven diets, containing 0~70% SBM, were made based on iso-nitrogenous and iso-caloric basis of 44% crude protein. Ajpparent digestibility of phosphorus was measured 60 and 120 days after feeding. The digestibility coefficient increased gradually as the level of SBM increased up to 46~58%, but decreased at 58~70% SBM level. Phosphorus concentrations in feces decreased with an increased in dietary SBM level. Patterns of post-prandial phosphorus excretion were not similar to those of ammonia excretion, but the amount decreased with the increased SBM level in the diets. Total excretion of phosphorus for 24 hours was 19.68mg.kg-1 body wt..day-1 in the control group, but excreted phosphorus by the 58% and 70% SBM groups was 63.4% and 56.1% of the control group, respectively. Phosphorus concentration of whole body decreased with an increase in dietary SBM level for 120 days of feeding. However, there were no significant differences in phosphorus concentrations of liver among the experimental groups, except for 70% SBM diet group.

• Fisheries and Aquatic Sciences
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• v.4 no.4
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• pp.186-191
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• 2001

Vitellogenin (VTG) and VTG mRNA induction by $estradiol-17\beta\;(E_2)$ were examined in the primary cultures of hepatocyte in the rainbow trout. Hepatocytes were precultured for 2 days, then $E_2$ was added and cultured for another 5 days. Media and hepatocytes were then analyzed by electrophoresis and Northern blotting for VTG and VTG mRNA, respectively. The hepatocytes were formed a few aggregates within 5 days without further spreading to a monolayer. Cell viability and high DNA content were maintained during the incubation. The hepatocyte culture with E2 induced a weak VTG band at a molecular weight of 175kDa on Day 2 after $E_2$ addition. The relative amount of VTG was expressed in percentage of total protein concentrations. VTG was gradually increased as $1.9\%$ on Day 2, $6.3\%$ on Day 4 and $7.3\%$ on Day 5. VTG mRNA band was detected at about 6.6 kb in the culture with $E_2$ at day 1 of culture. The level of VTG mRNA expression linearly increased with time until Day 5 (r=0.97).

• Journal of Fisheries and Marine Sciences Education
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• v.24 no.2
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• pp.224-233
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• 2012

Hazard Analysis and Critical Control Points (HACCP) is a systematic preventative approach for food safety and is generally used in food industry to identify potential food safety hazards. Recently, the Korean Ministry for Food, Agriculture, Forestry and Fisheries planed to applicate HACCP programs as an effective approach to food safety and protecting public health at the aquaculture farm of rainbow trout, Oncorhynchus mykiss. For the purpose, it need to identify what kinds of hazards are in the aquaculture farm. In the present study, we established Sanitation Standard Operating Procedures (SSOP), which addresses sanitation conditions and practices in the aquaculture farm. SSOP is essential prerequisite programs of HACCP to reduce or eliminate the risk of the hazards being realized. We anticipate that the HACCP programs of aquaculture farm will contribute to supply foods in safety to consumers.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.4
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• pp.828-835
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• 2013

Products from aquaculture have sometimes been focused on the problems caused by the contamination of chemical agents as the use of chemical agents in aquaculture has been annually increased. The risk of contamination of products by chemical agents is greater in freshwater than in seawater. In order to evaluate the food safety of a fish grown in freshwater, we investigated the residues of antibiotics (tetracycline, oxolinic acid and ciplofloxacin) and malachite green in cultured rainbow trout, Oncorhynchus mykiss. Malachite green, which was prohibited in the application of aquaculture, was not detected in samples tested in this study. The residual content of tetracycline was determined to be less than the permissible amount, <0.2 mg/kg. The contents of ciplofloxacin was also less than the permissible amount, <0.1 mg/kg. However, in case of oxolinic acid, one of samples was only exhibited higher content than the permissible amount (<0.1 mg/kg). The results obtained in this study suggested that the control and regulation of chemical agents such as antibiotics was important to maintain a safe and worry-free seafood supply.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.159-164
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• 2003

Effects of Al on vitellogenin (VTG) and VTG mRNA induction by estradiol-17 $\beta$($E_2$) were examined in primary hepatocyte culture of rainbow trout. Hepatocytes were precultured for 2 days and then E2 ($2{\times}10^{-6}$M) and Al ($10^{-6}-10^{-4}$M) were simultaneously added to the incubation medium. Hepatocytes were cultured for 5 more days. Media and hepatocytes were then analyzed by SDS-PAGE and Northern blotting for VTG and VTG mRNA, respectively. These metal had no appreciable effect on the viability of hepatocytes in culture. However, Al interfered with VTG production and VTG mRNA expression. Al reduced VTG production in a concentration-dependent way and a significant reduction accurred at Al concentrations greater than $5{\times}10^{-5}$M. VTG mRNA expression also decreased with a negative correlation with Al concentration (r＝-0.98). These results suggest that Al inhibit VTG production at the transcriptional level to reduce VTG mRNA expression.