• 한국수산과학회지
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• 제41권4호
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• pp.248-252
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• 2008

A 6-week feeding trial was conducted to investigate effects of dietary supplementation with wood vinegar (WV) as a feed additive for juvenile olive flounder, Paralichthys olivaceus. Eight experimental diets supplemented with 0(control), 0.01, 0.025, 0.05, 0.1, 0.25, 0.5 and 2.0% WV/kg diet($WV_0,\;WV_{0.01},\;WV_{0.025},\;WV_{0.05},\;WV_{0.1},\;WV_{0.25},\;WV_{0.5},\;and\;WV_{2.0}$, respectively) were prepared by mixing with basal diet. After the 6-week feeding trial, fish fed the $WV_{0.1}$ diet had significantly higher weight gain, feed efficiency, and specific growth rate than those of fish fed the other diets(P<0.05). No mortality was observed in the treatment groups fed the experimental diets for 6 weeks. The liver antioxidant activity of fish fed the $WV_{0.01},\;WV_{0.025},\;and\;WV_{0.05}$ diets was significantly higher than that of fish fed the other diets. The lysozyme activity of fish fed the $WV_{0.25}$ diet was significantly higher than that of fish fed the other diets. Fish fed diets supplemented with WV had significantly lower cumulative mortality than that of fish fed the control diet throughout the challenge test, and fish fed the $WV_{0.05}\;and\;WV_{0.1}$ diets had the highest resistance to disease caused by Edwardsiella tarda at day 7 of the challenge test. Therefore, feeding 0.05-0.1% WV/kg diet improves the growth and immune responses of juvenile olive flounder, Paralichthys olivaceus.

• 한국수산과학회지
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• 제46권4호
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• pp.377-383
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• 2013

We ran a feeding trial to determine optimal dietary protein and lipid levels for growth of juvenile long snout bullhead Leiocassis longirostris Gunther. Eight experimental diets (P20L7, P20L14, P30L7, P30L14, P40L7, P40L14, P50L7 and P50L14) were formulated to contain 20%, 30%, 40% or 50% protein combined with either 7% or 14% lipid. Three replicate groups of fish (mean mass: 3.9 g/fish) were fed one of the experimental diets ad libitum for 8 weeks. Survival of fish fed the P20L14 diet was lower than that of fish fed the P40L14, P50L7 and P50L14 diets. Growth of fish fed diets containing 7% lipid increased with increasing protein level (up to 50% protein); growth of fish fed diets containing 14% lipid increased with increasing protein level (up to 30% protein). The feed efficiency of fish fed a diet with 50% protein and 7% lipid was higher than that of other groups. Whole body moisture and lipid contents were affected by dietary lipid level but not by dietary protein level. The crude lipid contents of fish fed 14% lipid diets were higher than those fed 7% lipid diets across all protein levels (other than the 50% level). Thus, under our experimental conditions, an increase in dietary protein level improved growth and feed efficiency of fish; a diet containing 50% protein with 7% lipid was optimal for growth and effective feed utilization in juvenile long snout bullhead.

• Asian-Australasian Journal of Animal Sciences
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• 제21권9호
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• pp.1367-1375
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• 2008

This study was conducted to investigate the effects of phytase in diets containing cottonseed and soybean meal (CS) on growth performance, feed utilization and digestibility of protein and phosphorus in juvenile olive flounder (initial body weight 2.5 g), Paralichthys olivaceus. Four experimental diets replacing 0%, 30%, 30% and 40% fish meal protein with CS in equal proportion were formulated to be isonitrogenous and isocaloric (designated as CS0, CS30, CS30+P, CS40+P, respectively). Phytase of 1,000 FTU/kg was supplemented in diets CS30+P and CS40+P. Three groups of fish (25 fish per group) were fed one of the experimental diets for 10 weeks. No significant differences were observed in growth performance of fish groups except for the CS40+P diet. Apparent digestibility coefficients of protein and phosphorus in fish fed phytase-containing diets were significantly higher than those of fish fed the CS0 diet. Serum cholesterol was significantly reduced in fish fed the CS-containing diets. Antioxidant activities in the diets and liver of fish were significantly increased with the increment of dietary CS. Gossypol was only detected and found in liver of the fish fed the CS-containing diets. The findings suggest that supplementation of microbial phytase could improve the apparent digestibility of protein and phosphorus in juvenile olive flounder fed the CS-containing diets.

• 한국수산과학회지
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• 제49권5호
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• pp.683-688
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• 2016

The effects of dietary supplementing natural additives [yacon (YC), ginger (GG), and blueberry (BB)] on growth, feed utilization, and body composition of juvenile rockfish were compared to those of ethoxyquin (EQ), which is commonly used to prevent rancidity of fish feed. A total of 480 fish were distributed randomly into 12 50-L flow-through tanks (40 fish/tank). Four experimental diets were prepared: the control diet (Con) with 0.01% EQ, and the YC, GG and BB diets containing 1% YC, GG, and BB instead of wheat flour. Each diet was assigned randomly to triplicate tanks of fish, which were hand fed to satiation twice daily for 8 weeks. Weight gain of fish fed the YC diet was higher than that of fish fed all other diets. Feed efficiency (FE), protein efficiency ratio (PER), and protein retention (PR) in fish fed the YC diet were higher than those in fish fed the other diets. Whole-body chemical composition of the fish was affected by the additive sources. In conclusion, dietary supplementation with GG effectively improved weight gain and feed utilization (FE, PER, and PR) of juvenile rockfish.

• 생태와환경
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• 제37권1호통권106호
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• pp.130-136
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• 2004

저수지화성향을 띤 낙동강은 수체가 정체되는 시기에 높은 동물플랑크톤 밀도를 보인다. 이 시기의 높은 치어개체군 밀도는 지각류 개체군 밀도의 감소와 윤충류 개체군 밀도의 증가를 유도하는 주요요인으로 제시되었다. 본 연구에서는 실험실실험을 통해 치어의 먹이선호도와 포식이 낙동강 동물플랑크톤 군집에 미치는 영향을 평가하였다. 여러 종류의 치어의 먹이선호도 및 크기가 다른 치어의 먹이선호도를 실험실 수조내에서 평가하는 한편, 대형 수조에서 이들 치어의 포식이 동물플랑크톤군집에 미치는 영향을 모니터링 하였다. 실험에 사용된 세종류의 치어 (Hyporhamphus sajori, Rhinogobius brunneus, Opsariichtys uncirostris) 및 크기가 다른 치어 (O. uncirostris) 모두지각류 Moina micrura에 가장 높은 먹이선호도를 나타냈다. 야외수조에서 실시된 실험에서 치어의 포식은 지각류 M. micrura를 억제하는 한편 윤충류인 Polyarthra spp.의 우점을 유도하였다. 본 실험결과. 치어의 섭식은 낙동강에서 동물플랑크톤 군집구조를 결정하는 중요한 요인으로 사료된다.

• Fisheries and Aquatic Sciences
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• 제17권4호
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• pp.449-454
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• 2014

The effects of food deprivation and feeding ratio on the growth, feed utilization and body composition of juvenile olive flounder Paralichthys olivaceus were investigated in 810 juvenile fish averaging 6.4 g in weight randomly distributed in 27 400-L flow-through tanks. A 3 [food deprivation: 8-week feeding without food deprivation (8W), 7-week feeding after 1-week food deprivation (7W) and 6-week feeding after 2-week food deprivation (6W)]${\time}3$ (feeding ratio: 100%, 95% and 90% of satiation, hereafter denoted by 100, 95 and 90, respectively) factorial design was applied. The weight gain of the fish was significantly affected by both food deprivation and feeding ratio. The weight gain of the fish under the 8W-100 treatment was higher than that of those under the 7W-95, 7W-90, 6W-100, 6W-95 and 6W-90 treatments, but did not differ from those of fish under the 8W-95, 8W-90 and 7W-100 treatments. The specific growth rate (SGR) and the feed intake of the fish were affected by both food deprivation and feeding ratio. However, the feed conversion ratio (FCR) was unaffected by both food deprivation and feeding ratio. The protein efficiency ratio (PER) was affected by the feeding ratio, but not by food deprivation. The protein retention (PR) was affected by food deprivation, but not by feeding ratio. Juvenile olive flounder subjected to 1-week food deprivation at 100% satiation (7W-100 treatment) achieved full compensatory growth.

• 한국수산과학회지
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• 제55권3호
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• pp.379-385
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• 2022

This study was conducted to evaluate the dietary supplementation of citrus byproduct (CBP) on the growth performance, feed utilization, and innate immune responses of juvenile olive flounder Paralichthys olivaceus under low water temperatures (11-15℃). Dietary L-ascorbyl-2-polyphosphate was replaced with graded CBP levels at 0 (Con), 25 (CBP25), 50 (CBP50), 75 (CBP75), and 100% (CBP100). Triplicate groups of juvenile olive flounder were handfed with one of the diets twice a day for 42 days. The growth performance and feed utilization of fish fed with diet containing levels of CBP75 or CBP100 increased significantly compared to those of fish with fed Con. Dietary CBP supplementation increased the protein efficiency ratio in fish. There was no significant differences in innate immune responses between groups, even though CBP supplementation tended to increase. These findings indicate that CBP could be used as a vitamin C source and improve the growth performance of juvenile olive flounder under low water temperatures.

• Asian-Australasian Journal of Animal Sciences
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• 제27권10호
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• pp.1478-1486
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• 2014

The present experiment was conducted to evaluate the efficacy of dietary fermented by-product of mushroom, Pleurotus ostreatus, (FBPM) as a fish meal (FM) replacer in juvenile Amur catfish, Silurus asotus. A total number of 225 fish averaging $5.7{\pm}0.1g$ ($mean{\pm}standard$ deviation) were fed one of the five experimental diets formulated to replace FM with FBPM at 0%, 5%, 10%, 20%, and 30% ($FBPM_0$, $FBPM_5$, $FBPM_{10}$, $FBPM_{20}$, and $FBPM_{30}$, respectively). At the end of eight weeks of the experiment, average weight gain (WG) of fish fed $FBPM_0$ or $FBPM_5$ were significantly higher than those of fish fed $FBPM_{20}$ or $FBPM_{30}$ diets (p<0.05). However, there was no significant differences in WG among the fish fed $FBPM_0$, $FBPM_5$ or $FBPM_{10}$, and between fish fed $FBPM_{10}$ or $FBPM_{20}$, and also between those fed $FBPM_{20}$ or $FBPM_{30}$ diets. Lysozyme activity of fish fed $FBPM_0$ or $FBPM_5$ were significantly higher than those of fish fed $FBPM_{10}$, $FBPM_{20}$ or $FBPM_{30}$ diets (p<0.05). The chemiluminescent response of fish fed $FBPM_5$ was significantly higher than those of fish fed $FBPM_0$, $FBPM_{20}$ or $FBPM_{30}$ diets (p<0.05). Broken line regression analysis of WG suggested that the maximal dietary inclusion level for FBPM as a FM replacer could be 6.3% without any adverse effects on whole body composition and on serological characteristics. Therefore, these results may indicate that the maximal dietary inclusion level of FBPM as a FM replacer could be 6.3% in juvenile Amur catfish.

• Fisheries and Aquatic Sciences
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• 제13권4호
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• pp.300-307
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• 2010

This study examined the effects of the dietary inclusion of various concentrations of red ginseng byproduct (RB) and a mixture containing red ginseng byproduct, garlic extract, yeast and filler (CR) on the growth, body composition, serum chemistry, and lysozyme activity of juvenile olive flounder (Paralichthys olivaceus). Juvenile fish (n= 630) weighing 5.0 g were randomly distributed into 21 180 L flow-through tanks (30 fish/tank). Seven experimental diets were prepared in triplicate: a control diet without additive, and diets containing 0.5, 1 and 2% concentrations of RB (RB-0.5, RB-1, RB-2) and CR (CR-0.5, CR-1, CR-2) at the expense of wheat flour. After an 8-week feeding trial, serum chemistry and lysozyme activity of fish were measured. Mean weight gain was significantly higher in fish fed the control diet than in fish fed the RB and CR diets. The dietary inclusion of RB and CR reduced feed utilization. Mean serum glucose and triglyceride (TG) levels were higher in fish fed the control diet than in fish fed the other diets. Mean glutamate pyruvate transaminase (GPT) levels of fish fed the control and RB-2 diets were higher than those of fish fed the RB-0.5, RB-1, CR-1, and CR-2 diets. Mean lysozyme activity levels of fish fed the RB-0.5 and RB-1 diets were higher than those of fish fed the control and CR diets. The results of this study indicate that red ginseng byproduct may be utilized as an immunostimulant rather than as a growth promoter for juvenile olive flounder. Dietary inclusion of 0.5% red ginseng byproduct effectively improved serum glucose, GPT, TG, and lysozyme activity of the fish in this study.

• Fisheries and Aquatic Sciences
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• 제13권2호
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• pp.182-189
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• 2010

An active stimulating device (ASD) using a rope apparatus may operated by the flow of turbulence inside a cod end, generating variable stimuli in addition to flow-related effects to minimize the by-catch of juvenile fishes. Preliminary testing involved a hydrodynamic effect inside the cod end with a rotating rope kite or conical rope array to generate variable stimuli (visual stimuli, water flow, or physical contact with fish) to change fish position. The experimental rope kite offered more choice in rotating period and range of sweeping action; adjusting the towing line or flow velocity helped to drive fish toward the net panel and encouraged escape. The conical shape of the rope array in the cod end helped to clear a path for fish by disturbing the rigging and providing more contrast between objects, preventing an optomotor response. This enabled more black porgy to be herded toward the net at an early stage of towing. Therefore, either a conical rope array or a rotating rope kite can be used as an effective ASD to prevent juvenile by-catch.