• Fisheries and Aquatic Sciences
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• v.19 no.5
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• pp.24.1-24.6
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• 2016

We determined the optimum dietary protein level in juvenile barred knifejaw Oplegnathus fasciatus in cages. Five semi-purified isocaloric diets were formulated with white fish meal and casein-based diets to contain 35, 40, 45, 50, and 60 % crude protein (CP). Fish with an initial body weight of $7.1{\pm}0.06g$ ($mean{\pm}SD$) were randomly distributed into 15 net cages (each size: $60cm{\times}40cm{\times}90cm$, $W{\times}L{\times}H$) as groups of 20 fish in triplicates. The fish were fed at apparent satiation level twice a day. After 8 weeks of feeding, the weight gain (WG) of fish fed 45, 50, and 60 % CP diets were significantly higher than those of fish fed 35 and 40 % CP diets. However, there were no significant differences in WG among fish fed 45, 50, and 60 % CP diets. Generally, feed efficiency (FE) and specific growth rate (SGR) showed a similar trend as WG. However, the protein efficiency ratio (PER) was inversely related to dietary protein levels. Energy retention efficiency increased with the increase of dietary protein levels by protein sparing from non-protein energy sources. Blood hematocrit content was not affected by dietary protein levels. However, a significantly lower amount of hemoglobin was found in fish fed 35 % CP than in fish fed 40, 45, 50, and 60 % CP diets. Fish fed 60 % CP showed the lowest survival rate than the fish fed 35, 40, 45, and 50 % CP diets. Broken-line analysis of WG showed the optimum dietary protein level was 45.2 % with 18.8 kJ/g diet for juvenile barred knifejaw. This study has potential implication for the successful cage culture of barred knifejaw.

• Journal of Aquaculture
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• v.16 no.4
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• pp.257-261
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• 2003

The effects of different stocking densities on the growth of juvenile abalone, Haliotis discus hannai and water quality in the recirculating system with rotating biological contactor, were assessed. The trials were conducted using total weight 32 g juveniles abalone for 60 days at stocking densities of 5, 10, 15 kg/$m^2$. The animals were fed sufficient amounts of the pellet diet of 30.4% protein during the experimental period. Daily feeding rate (DFR) and survival rate (SR) of 5 kg/$m^2$ showed 0.76% and 85.5% those were not significantly differed 10 kg/$m^2$ showing 0.75% and 96.0% (P>0.05). DFR and SR of 15 kg/$m^2$ showing 0.38% and 31.2% were significantly lower than 5 and 10 kg/m2 (P<0.05). Daily growth rate (DGR) and feed efficiency (FE) showed the highest as 0.19% and 24.2% in 5 kg/$m^2$ the lowest as 0.05% and 14.3% in 15 kg/$m^2$ (P<0.05). According to, these results was an inverse relationship between growth and stocking density. The optimum density of juvenile abalone from this experiment is 5 to 10 kg/$m^2$ in the recirculating system.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.37 no.1
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• pp.43-53
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• 2011

The conditions in fluid-bed processor for nanoencapsulation of azelaic acid-milk nano powder for acne nanocosmetics were optimized by response surface methodology (RSM). The maximum value of yield was 70.97 %. The yield was appreciably influenced by inlet air temperature, atomizing pressure, and feeding speed. The particle size increased with an increase in the feeding speed and a decrease in the atomizing pressure. The elution rate in saline solutions was appreciably influenced by inlet air temperature and atomizing pressure. The moisture content increased with higher atomizing pressure, which was demonstrated to be similar to the nanoencapsulation characteristics related to water activity. The Hunter's L and b values increased with an increase in the inlet air temperature. The optimum conditions estimated by RSM for the maximized values of yield, moisture content, particle size and elution rate in skin suitability were $67{\sim}73^{\circ}C$ of inlet air temperature, 0.6 ~ 0.8 mL/min feeding speed and 1.8 ~ 2.0 kg/$cm^2$ of atomizing pressure, respectively. These estimated values were in agreement with those measured by real experiments.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.4
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• pp.179-186
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• 1974

The followings are some results obtained from a series of experiments for the culture of eels from the elver stage in the laboratory from April 1973 to June 1974. 1. The optimum temperature turned out as 30t in the early stage culture. 2. The exponential curve of growth rate for a ten day period at the temperature between $20^{\circ}C$ and $30^{\circ}C$ was represented by the following equation: $$R=0.0056296\;T^{1.80740}$$ 3. The elvers and small eels that were kept improperly for a long time before this experiment also showed the same growth rate, compared with other healthful eels captured directly from the estuarine areas. 4. Those that showed retarded growth among a group of eels during the culture recovered the normal growth rate if graded out and kept in the other aquarium. 5. Feeding rate was not affected when the content of ammonia was less than 5 ppm, but it decreased by half when the content exceeds 6 ppm. 6, The elimination of fecal stuffs and uneaten dispersed feed was very important for the maintaining the water in quality.

• Food Engineering Progress
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• v.13 no.4
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• pp.269-274
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• 2009

The main objective of this study was to establish optimum condition of wet grinding process for manufacturing microparticulated seaweed calcium. Process parameters such as concentration of forming agent, rotor speed, bead size, feed rate, and grinding time were adapted during wet-grinding of seaweed calcium. The particle size range of the raw seaweed calcium was 10-20 $\mu$m. The calcium particles were reduced to under 1 $\mu$m as nano scale after grinding. Gum arabic was suitable for forming agent and 5%(w/v) concentration was the most effective in grinding efficiency. A wet-grinding process operated at 4,000 rpm rotor speed, 0,4 mm bead size, and 0.4 L/hr feeding rate, respectively, produced less than 600 mm(>>90%)-sized particles. In batch systems, 8 cycles of grinding showed higher efficiency, but 20 min of grinding time in continuous processing was more efficient to reduce particle size than the batch processing. Based on the result, the optimum conditions of the wet grinding process were established: operation time of 20 minutes, rotor speed of 4,000 rpm, bead size of 0.4 mm, feed rate of 40 mL/min and 30% mixing ration with water. The size of the resulting ultra fine calcium particles ranged between 40 and 660 mm.

• KSBB Journal
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• v.11 no.4
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• pp.497-503
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• 1996

In this study, the effects of nitrogen sources and pH on pullulan production were investigated. As a result, the best nitrogen source in pullulan production by Aureobasidium pullulans was shown to be peptone and its product yield was 62%. Optimum concentration of carbon/nitrogen source ratio was 50/0.15 and the production of pullulan was inhibited at ratios higher than 50/0.15. Aureobasidium pullulans had produced 29.1, 27.4 and 26.5 g/L pullulan, respectively in media I, II, and III containing mixed nitrogen sources. This result showed that pullulan could be produced efficiently from mixed nitrogen source. It was found that pullulan yield with pH control was higher than that with no pH control. In fedbatch fermentation, pullulan yield obtained with a feeding rate of 0.05 N-g/L for nitrogen source was higher than that without nitrogen source feeding.

• KSBB Journal
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• v.9 no.1
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• pp.35-39
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• 1994

Separation of pure fructo-oligosaccharides from the mixed solution of glucose, sucrose and fructo-oligosaccharides was studied using a cationic ion-exchange resin column. Optimum separation conditions, i.e., temperature, feeding rate and the ratio of column vs. diameter were evaluated, which were found to be $85^{\circ}C$, $0.25h^{-1}$ and 30, respectively. At the optimized separation conditions, high-purity fructo-oligosaccharides up to 96% were obtained and the total recovery yield was about 66% after four cycles. After the chromatographic separation, purification to remove the salts and color in pure fructo-oligosaccharides solution was successfully conducted using the mixed-bed of cationic and anionic ionexchange resin columns.

• Journal of Korean Society on Water Environment
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• v.21 no.1
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• pp.79-83
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• 2005

Foraging behaviour of false dace, Pseudorasbora parva, was investigated in water flowing at various velocities with the existence of a cavity for rest. The pursuit comprised three succeeding processes such as, approaching, chasing and attacking. Angles between the fish body and the water flow direction and swimming speeds increased in the latter stages of approaching, chasing and attacking. All pursuit angles, swimming speeds and distances increased with flow velocity and peaked at the flow velocity of 7 cm/sec. At higher velocities, however, the fish avoided the use of much energy against the large drag force. The probability of capture and the feeding rate steadily decreased with increasing flow velocity. Under the fast flow, the fish adjusted their swimming speed to get the optimum velocity relative to the flowing water for the energetic budget. Fish spent more time in the cavity as flow velocity increased to avoid the energy expenditure necessitated by the high velocity.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.9
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• pp.1245-1249
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• 2001

A study was conducted with 14 gayals to study their growth pattern from birth to 24 months of age, and gayal was compared with native calves and crossbred calves of gayals and exotic animals. A significant difference in liveweight gains up to 3 months (p<0.001) or up to 6 months (p<0.05) was found between gayal and native calves, but the difference reduced with increase of age and found non-significant (p>0.05) at 9 months and 12 months. The daily liveweight gain up to 3, 6, 9 or 12 months of age of gayals were 404.60, 306.80, 315.20 and 312.20 g/d, respectively and of native calves were 217.3, 245.3, 262.0 and 269.0 g/d, respectively. Gayal female calves had lower weights at birth (20.2 kg) and weaning (81.8 kg) and daily liveweight gains (298.5 g/d) than males (24.3 kg, 84.0 kg and 317.8 g/d, respectively) but the differences were not significant (p>0.05). Cross breeding gayal cows with Friesian bulls increased daily liveweight gain of the crossbred calves. The rate of increase of daily liveweight gain may further be increased if gayals are crossed with beef type animals, and optimum feeding may also be required which needs further research.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.1
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• pp.26-33
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• 2009

This experiment was conducted to examine the utilization of added dietary selenium (Se) as an immune stimulant in juvenile olive flounder, Paralichthys olivaceus. Fish averaging $4.0{\pm}0.1\;g$ ($mean{\pm}SD$) were fed one of seven semi-purified diets containing 0.56, 1.07, 2.86, 4.56, 43.15, 90.71, or 161.74 mg of Se/kg ($Se_{0.56}$, $Se_{1.07}$, $Se_{2.86}$, $Se_{4.56}$, $Se_{43.2}$, $Se_{90.7}$ and $Se_{161.7}$, respectively) for 12 weeks, respectively. At the end of the feeding trial, the fish fed diets containing more than 43.2 mg of Se/kg showed above 90% mortality. There were no significant differences in weight gain, feed efficiency, specific growth rate, protein efficiency ratio, or hematological characteristics among the fish fed the $Se_{0.56}$, $Se_{l.07}$, $Se_{2.86}$, and $Se_{4.56}$ diets. Se concentrations of the gill, kidney, muscle and liver tissues occurred in dose-dependent manners. Alternative complement pathway activation and the chemiluminescene responses of the fish fed the $Se_{1.07}$ diet were significantly higher than those of the fish fed the other diets (P<0.05). These results indicate that the optimum dietary supplementation level of Selenium as selenoyeast could be 1.07 mg of Se/kg based on the non-specific immune responses of juvenile oilve flounder, Paralichthys olivaceus.