• 한국양식학회지
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• 제18권4호
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• pp.267-271
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• 2005

A feeding trial was carried out to investigate the effect of various fish meals as dietary protein source on growth, feed utilization and body composition of Juvenile flounder. Ten experimental diets were prepared to contain different fish meals: 4 kinds of white fish meal (WM-1, 2, 3, 4), 3 kinds of herring meal (HM-1, 2, 3), mackerel meal (MM), WM mixture and HM+MM mixture. Dietary energy and protein levels were designed to be isocaloric ($3.8 kcal g^{-1}diet$) and isonitrogenous ($46\%$) by adjusting the levels of fish meal, wheat flour and squid liver oil. Three replicate groups of fish (initial mean weight: 11.1 g) were hand-fed to visual satiety two times daily for 7 weeks. Survival was not significantly different among all groups. Weight gain of fish fed the HM-1 and HM-3 diets was the highest, but not significantly different from that of fish fed the either WM-2 or HM+MM diets. The lowest weight gain was found in fish fed the W-1 and WM-3 diets. Feed efficiency and protein efficiency ratio of fish fed the WM-2, HM-1, HH-3, MM and HM+MM diets were significantly higher than those of fish fed other diets. Daily feed intake of fish fed the WM-3 diet was highest, but not significantly different from that oi fish fed the either WM-4 or WMM diet. Significant differences were found in contents of moisture, crude protein, crude lipid and ash of whole body of fish. The results of this study indicated that growth of flounder can be affected by dietary fish meal source and quality, and WM-2, HM-1, HM-3 and HM+MM mixture are considered as useful dietary fish meal sources under these experimental conditions.

• Fisheries and Aquatic Sciences
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• 제12권4호
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• pp.258-264
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• 2009

A commercial diet supplemented with carotenoids and conjugated linoleic acid was fed to rainbow trout (Oncorhynchus mykiss) for 8 weeks. To investigate the anti-oxidative properties of these compounds, lipids from the muscle and viscera of the fish were subjected to different assays. At $10\;{\mu}g/mL$, L-ascorbic acid exhibited 95% 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, while the tissue lipids showed little radical scavenging activity. At 50 and $100\;{\mu}g/mL$, the lipids of the muscles and viscera showed 11.7-22.6% and 11.3-24.9% DPPH radical-scavenging activity, respectively. A lipid peroxidation inhibitory assay using the ferric thiocyanate method was also performed in comparison with $\alpha$-tocopherol at a concentration of 6.0 mg/mL. Our results indicate that the anti-oxidative property of the lipids in fish muscle, which was 85.2% compared to 85.3% for the visceral lipids, was stronger than that of $\alpha$-tocopherol (74.3%) following 3 days of storage at $40^{\circ}C$.

• Ocean and Polar Research
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• 제26권3호
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• pp.415-423
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• 2004

An experiment was conducted to investigate the differences of total ammonia nitrogen (TAN) excretion rates and feces production rates among the offsprings from cultured Japanese strain (JJ, mean BW; $17.1{\pm}0.1g$), intraspecific hybrid strain between cultured Japanese and selected Korean strain (JK, mean BW: $17.1{\pm}0.1g$) and selected Korean strain(KK, mean BW: $21.5{\pm}0.1g$) of red sea bream in order to compare their dietary protein utilization efficiency. Fish were hand-fed with a commercial diet containing 46.7% crude protein for 2 weeks, three times daily 09:00, 13:00 and 17:00. After daily feeding, the TAN excretion rates reached peaks of 49.03, 58.75 and 36.26mg/kg fish/hr for the JJ, JK and KK strain, respectively, during the daytime. The value of the KK strain was significantly lower than that of the JJ and JX shuin (P<0.05), however daily TAN excretion rates of the JJ, JK and KK strain were not different (P>0.05). When fish were fed at satiation after 4 days of starvation, TAN excretion rates reached the maximum values 4 hours after the feeding fur the KK (31.23 mg/kg fish/hr) and 6 hours after the feeding fur the JJ (44.19 mg/tg fish/hr) and JK strain (41.70 mg/kg fish/hr). After 3 days of starvation, the daily endogenous TAU excretion rates (ETE) for the JJ, JK. and KK strain were 286.91, 215.66 and 179.29mg/kg fish/day, respectively. The value of the KK strain was lower than that of the JJ and JK strain (P<0.05). The total feces production rates of the JJ, JK and KK strain were not significantly different, however the proportions of feces production rates by time for the JJ, JK and KK strain were different (P<0.05). As overall results, efficiency of dietary protein utilization of JJ, JK and KK seems to be different and KK strain could offer a desirable option for aquaculture purpose.

• 한국수산과학회지
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• 제42권2호
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• pp.116-122
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• 2009

This study was conducted to compare the food quality of commercial salt-fermented silver-stripe round herring (SFS) to that of commercial salt-fermented anchovy (SFA). The contents of moisture and crude protein of SFS were higher than those of SFA. However, the crude lipid and crude ash contents of SFS were lower than those of SFA. The salinity of SFS was 13.2%, which was lower than that of SFA. The taste value of SFS was 148.1, which was higher than that of SFA. The total amino acid content of SFS was 18.1 g/100 g and its major amino acids were glutamic acid (9.5%) and aspartic acid (8.1%). The contents of calcium, phosphorus and iron in SFS were 647 mg/100 g, 363 mg/100 g and 4.1 mg/100 g, respectively. Twenty six types of fatty acids were detected in SFS and the major components were 16:0, 18:0, 18:1n-9 and 22:6n-3. The angiotensin I converting enzyme (ACE) inhibiting and the antioxidative abilities of SFS were 50.0% and 1.15, respectively, which were similar to those of SFA. Sensory evaluation revealed that SFS had a superior taste and color to SFS, while to the flavor of two products was similar.

• 한국수산과학회지
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• 제48권4호
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• pp.417-425
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• 2015

Semi-dried conger eel Conger myriaster is considered as a health food in Korea due to its richness in vitamins, minerals, proteins and omega-3 fatty acids. This study characterize the sanitary quality of commercial semi-dried conger eel for developing high quality semi-dried products and suggested the guideline for controlling the quality. Moisture content ranged from 41.2% to 73.4% (mean: 61.5%), volatile basic nitrogen ranged from 16.1 to 93.6 mg/100 g (mean: 55.1 mg/100 g), and peroxide value ranged from 15.2 to 69.8 meq/kg. Viable cell counts ranged between 6.51 and 8.53 log CFU/g, while the Escherichia coli count ranged from undetectable to 4.6 log CFU/g. Based on these chemical and microbial findings, we suggest that provisions be established for development of high quality semi-dried conger eel as follows: 50-68% for moisture content, < 50 mg/100 g for volatile basic nitrogen content, < 60 meq/kg for peroxide value, and negative for E. coli. Among the 16 commercial semi-dried conger eel products used in this study, the standard-passed product was only GS-L.

• Fisheries and Aquatic Sciences
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• 제8권1호
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• pp.38-42
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• 2005

We evaluated the effects of different feeding strategies on the growth of young Nile tilapia, Oreochromis niloticus L., in a freshwater recirculating system during summer. Each of twenty fish (Mean body weight$\pm$ SD; 37. 7$\pm$0.10 g) were randomly distributed into each of 24 tanks. Eight treatments were prepared in triplicate. Control fish were hand-fed commercial feed twice daily without starvation. The other seven treatments employed different feeding and starvation strategies ranging from I day starved and 1 day fed (1DS+ 1DF) to 7 days starved to 7 days fed (7DS+7DF). All fish survived to the end of the 44-day feeding trial. The amount of food supplied was highest for the control fish in the control. Food supplied to fish in the 3DS+3DF and 4DS+4DF treatments was significantly lower than that of fish in the 1DS+1DF and 2DS+2DF treatments, but significantly higher than that of fish in the 5DS+5DF, 6DS+6DF and 7DS+7DF treatments. The weight gain of control fish was significantly higher than that of fish in other treatments. Feed efficiency ratio (FER) for fish in the 7DS+7DF treatment was significantly higher than that of fish in the control group, but it did not differ from that of fish in the 1DS+1DF and 2DS+2DF treatments. We concluded that young Nile tilapia raised with different starvation and feeding regimes during the summer in a freshwater recirculating system did not catch up in growth to fish fed daily. However, the enhanced FER of Nile tilapia in the 7DS+ 7DF, 2DS+ 2DF, and 1 DS+ I DF treatments partly explains the compensatory growth of the fish, although their weight gain was relatively low.

• 한국수산과학회지
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• 제44권2호
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• pp.149-154
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• 2011

Two experiments were conducted to investigate the effects of dietary moisture content on the growth and gastrointestinal evacuation of sub-adult olive flounder (Paralichthys olivaceus) in the summer and winter seasons. In the first experiment, three experimental diets containing different moisture levels (7%, 15%) and additives were prepared by adding water and commercial additives (1% nutrients, 1% digestives) to commercial extruded pellets. Fish (initial weight: $332{\pm}9.2$ g) were distributed randomly into six 3000 L tanks (25 fish/tank) in a flow-through tank system. Two replicate groups of fish were fed the experimental diets to satiation for 14 weeks during the summer season ($21.4{\pm}2.5^{\circ}C$). Survival, weight gain, feed efficiency, and daily feed intake did not differ significantly among groups. In the second experiment, two experimental diets containing different moisture levels (8%, 23%) were prepared by adding water to commercial extruded pellets. Fish (initial weight: $646{\pm}6.7$ g) were randomly distributed into six 3000 L tanks (20 fish/tank) in a flow-through tank system. Three replicate groups of fish were fed the experimental diets to satiation for 19 weeks during the winter season ($12.2{\pm}1.2^{\circ}C$). Weight gain, feed efficiency, and daily feed intake did not differ significantly among groups. Gastrointestinal evacuation rates were determined after the end of the winter feeding trials. The stomach contents of fish fed diets containing different moisture levels peaked within 3 h after feeding and then decreased gradually over 40 h to approach pre-feeding levels. Intestinal contents began to accumulate 3 h after feeding and reached a maximum at 32 h, then declined until nearly complete evacuation around 56 h. The stomach contents reached moisture levels of approximately 70% within 3 h after feeding and then increased gradually. No considerable difference in moisture levels was observed in the stomach contents of fish fed diets with different moisture contents. The results of this study suggest that the gastric evacuation of sub-adult olive flounder was not affected by dietary moisture level and the addition of water to the diet had no beneficial effect on the growth of sub-adult olive flounder in the summer and winter seasons.

• 한국수산과학회지
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• 제46권6호
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• pp.785-792
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• 2013

Two studies were conducted to investigate the effects of dietary nucleotides (NT) on the growth performance, hematological parameters, and innate immune responses of red seabream Pagrus major. In Expt I, six experimental diets were formulated: a control, four that contained each NT at a level of 0.15% (inosine monophosphate, IMP; adenosine monophosphate, AMP; guanosine monophosphate, GMP; and uridine monophosphate, UMP), and one with a 1:1:1:1 mixture of NTs (IMP, AMP, GMP, and UMP). In Expt II, five experimental diets were formulated that contained 0, 0.1, 0.2, 0.4, and 1.0% IMP (commercial product). Triplicate groups of juvenile (initial body weight 33.1 g) and growing (initial body weight 120 g) red seabream were fed one of the experimental diets to apparent satiation for 8 weeks in Expt I and 12 weeks in Expt II. In Expt I, fish fed diets with NT had higher growth performance than the control group. The nitroblue tetrazolium and lysozyme activities were higher in fish fed the mixed-NT diet, and lowest in the control group. In Expt II, the final body weight and feed utilization of fish fed the 0.1% IMP diet were significantly higher than those of fish fed the control or 1.0% IMP diets. Diet palatability was improved significantly when 0.1% IMP was added. The lysozyme activity was higher in fish fed diets with 0.4-1.0% than in the control group. These results suggest that supplementation of 0.15% IMP and Mixed-NTs in diet can enhance the growth and immune responses in juvenile red seabream. The optimum IMP level appears to be 0.2% in practical feed formulation for growing red seabream.

• 한국수산과학회지
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• 제44권6호
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• pp.644-652
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• 2011

Two consecutive studies were conducted to evaluate the effects of dietary supplementation with fermented garlic powder (FGP) or fermented garlic fluid (FGF) on growth performance, immune responses, and disease resistance of olive flounder Paralichthys olivaceus. In experiment I, olive flounder (BW: 65 g) were fed four experimental diets formulated to contain 0%, 0.5%, 1%, and 1.5% FGP (designated as FGP-0, FGP-0.5, FGP-1, and FGP-1.5, respectively). After the 10-weeks feeding trial, feed intake was significantly lower in fish fed the FGP-0.5 and FGP-1.0 diets, as compared to those fed the control diet. Fish fed the FGP-0 and FGP-0.5 diets showed significantly lower survival, as compared to the other treatments. Dietary supplementation with FGP resulted in higher non-specific immune responses than the FGP-0 group. Plasma cholesterol and triglyceride levels decreased as dietary FGP level increased. In experiment II, olive flounder (BW: 65 g) were fed four experimental diets for 10 weeks. The diets were prepared with a commercial expanded pellet to have 0%, 0.25%, 0.5%, and 1% FGF (designated as FGF-0, FGF-0.25, FGF-0.5, and FGF-1, respectively) by adsorption. At the end of the second feeding trial, feed intake was significantly lower in fish fed the FGF-0 diet, as compared to other treatments. Fish fed the FGF-0.25 and FGF-0.5 diets exhibited significantly lower cholesterol levels, as compared to other treatments. Lysozyme activity significantly increased with increases in dietary FGF. Cumulative mortality in a challenge test with Streptococcus iniae was significantly lower in the fish groups fed FGF-supplemented diets than in fish fed the control diet. The results of this study indicated that dietary supplementation with FGP or FGF can enhance the non-specific immune responses and disease resistance of olive flounder against S. iniae.

• 한국수산과학회지
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• 제47권3호
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• pp.234-240
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• 2014

We investigated the effects of feeding rate on the growth performance, blood components, and histology of growing olive flounder Paralichthys olivaceus. We determined the optimum feeding rate (initial fish mean weight of $240{\pm}10.9$ g) at the optimum water temperature. Two replicated groups of fish were fed a commercial diet at rates of 0%, 0.5%, 0.75%, and 1.0% body weight (BW) per day, and to satiation. Feeding trial was conducted using a flow-through system with 10 1.2-metric ton aquaria receiving filtered seawater at $19-21^{\circ}C$ for three weeks. Weight gain (WG) for fish fed to satiation was significantly higher than that of unfed fish and fish fed at 0.5% and 0.75% BW per day. The WG of fish fed at 1.0% BW per day was significantly higher than that of unfed fish and of fish fed at 0.5% BW per day. However, there were no significant differences in WG between fish fed at 0.5% BW per day and those fed at 0.75% BW per day, between fish fed at 0.75% BW per day and those fed at 1.0% BW per day, and between fish fed at 1.0% BW per day and those fed to satiation. The specific growth rates of fish fed at 1.0% BW per day and those fed to satiation were significantly higher than those of unfed fish and of fish fed at 0.5% BW per day. Broken-line regression analysis of weight gain showed that the optimum feeding rate of olive flounder weighing 240 g was 1.09% BW per day at the optimum water temperature.