• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.6
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• pp.805-811
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• 1995

Final biomass yields (peak optical density) and growth rates (divisions/day) of seven clones of Skeletonema costatum from Korean coastal waters were measured to understand their intraspecific variations in the light intensity niche component under $25^{\circ}C$ condition. Daily growth rates of 6 of 7 S. costatum, clones were maximum at 6000 lux while that of YS4, a neritic clone, was maximum at 9000 lux. The final biomass yields of 4 of the 7 S. costatum clones were maximum at the lowest light intensity of 2000 lux. Minimum final biomass yields were found at 9000 lux in all the S. costatum clones other than an estuarine clone, HDC9. The intraspecific variations of the mean growth rate and mean final biomass yield under each of the three different light intensity in terms of the coefficient of variation were not greater than 10% in any of the 7 S. costatum clones.

• The Korean Journal of Malacology
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• v.31 no.2
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• pp.73-81
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• 2015

This study was conduct to investigate the effect of intermediate culture types on the growth and survival rate of the juvenile abalone, Haliotis discus hannai fed seaweed and artificial diet. Intermediate cultures were to determine there that was to fed seaweed (SW) of artificial diet (A) of floor culture (FC), net floor culture (NFC), double shelter culture (DSC) and indoor net cage culture (INCC) in land-based tank, in two replicate. In the growth performance of juvenile abalone reared through intermediate culture to fed SW of A, that the absolute growth rate ($AGR_{SL}$, $AGR_{SB}$), daily growth rate ($DGR_{SL}$, $DGR_{SB}$), and specific growth rate ($SGR_{SL}$, $SGR_{SB}$) to the shell length (SL) and shell breadth (SB) of experimental groups were not significant. As weight gain (WG), daily weight gain (DWG) and specific weight gain (SWG) to body weight through intermediate culture types in land-based tank was not significant. However, as to survival rate to experimental groups, A-FC was higher than those of different groups (P < 0.05). Therefore, these results is showed that was not difference to growth of juvenile abalone over 2 cm fed seaweed diet and artificial diet according to intermediate culture types. But floor culture with artificial diet indicate that was highest to survival rate, therefore, it is beneficial for higher productivity in floor culture with artificial diet among intermediate culture types.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.1002-1006
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• 2002

Germination method was used to screen the biological changes in soybean, kidney bean, and red bean caused by gamma irradiation. Beans were irradiated at 0.1, 0.3, 0.5, 0.7, and 1.0 kGy. Ten beans of each sample were placed on moistened cotton and germinated at $30{\circ}C$. The root lengths were measured daily for 5 days. Root lengths of all beans grew continuously for 5 days, but the growth rate of irradiated beans decreased significantly from fourth day. Unirradiated beans showed the highest growth rate during 5 days of germination. Gamma-irradiated beans could be screened by measuring the daily growth rate and root length during germination.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.12
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• pp.1717-1725
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• 2000

The objective was to determine the relationship between feed intake levels and patterns, and growth performance and body composition of barrows and gilts using automatic feed intake recording equipment (F.I.R.E.). This system records the time of visits to the feeder and the duration and size of meals for individual animals housed in groups. Ninety-six crossbred pigs were grown from $33.4{\pm}0.51$ to $109.7{\pm}1.39kg$ live weight over a 13-week period. Eight mixed-sex groups of 12 pigs were used and 4 dietary treatments were compared giving 2 pens per treatment. The dietary treatments consisted of corn-soybean meal diets with differing protein levels which ranged from 14.7% to 19% between 30 to 55 kg, from 13.3% to 16.9% between 56 and 85 kg, and from 12.3% to 16.8% for the remainder of the study. Animals were ultrasonically scanned to measure loin-eye area and backfat thickness to estimate carcass fat-free lean content at the beginning and end of the study. Barrows had higher daily feed intake than gilts (2.67 vs. 2.46 kg resp. p<0.05) which was the result of a longer feeder occupation time per visit (4.77 vs. 4.54 min, resp. p<0.05), higher feed consumption rates (30.4 vs. 29.0 g/min, resp. p<0.05), and higher feed intakes per visit (136.9 vs. 126.8 g, resp. p<0.01). Gilts had less backfat and greater loin-eye area than barrows (p<0.05). Diet had no significant effect on growth performance and had limited impact on feeding patterns. Body weight showed high correlations with ADG (r=0.74), feed intake per visit (r=0.51) and feed consumption rate (r=0.69). Positive correlation were also found between daily feed intake and feed intake per visit (r=0.45), feeder occupation time per day (r=0.56), and feed consumption rate (r=0.55), and between daily feed intake and backfat thickness (r=0.32) and feed consumption rate and loin-eye area (r=0.32). There were negative correlations between number of feeder visit per day and daily feed intake (r=-0.54), and between feed intake per visit and number of feeder visits per day (r=-0.43). However, correlations between feed intake traits and carcass traits were generally low. Visits to the feeder were greatest during the morning (0700 to 1100 h) and lowest during the evening and nighttime. These results highlight limited variation among the sexes in feeding patterns and suggest important relationships between feeding behavior and feed intake.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.233-238
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• 1981

A recirculating water system without filter bed was used for a high density experimental rearing of common carp, Cyprinus carpio, during the summer of 1981. Of the water system, 3 tanks were used for stocking each tank with 10,000, 20,000 and 30,000 common carp fingerlings which averaged 0.6 g. The water in the system was maintained in dark green colour by heavy growth of phytoplankton during the most period of the experiment. In this experiment, the best daily growth rate, $3.7\%$, was obtained from the 10,000 fish group followed by $2.8\%\;and\;3.0\%$ from the 20,000 and 30,000 fish groups respectively. Thus there was no significant difference between the latter two groups. Especially, notably high concentration of total ammonia, $5\sim7$ ppm ammonia-N, in the culture water appeared during the most experimental period, but this did not seem to have affected feeding and growth of the fish when the water was kept at heavy bloom. It was also obvious that the outbreak of columnaris disease was effectively depressed in this green water recirculating system compared to that in clarified recirculating system. One tank ($7m^2$) of this system was stocked with 446 common carp of intermediate size averaging 352.2 g and after 40 day rearing they grew to 486.3 g in average with a daily growth rate of $0.8\%$. This result was a little inferior to that reared in a tank of the clarified water system as control which showed $1.0\%$ daily growth rate. Therefore, before an initiation of the commercial production of fish in this method, further studies concerning the amount of ammonium with its effect on the fish under rearing in this system and the columnaris disease problem should be carried out.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.753-760
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• 2013

Two feeding trials were conducted to investigate the effects of feeding rate and frequency on growth performance and body composition of juvenile Korean rockfish Sebastes schlegeli reared at $15.0{\pm}0.3^{\circ}C$. In the first trial, three replicate fish groups averaging $2.07{\pm}0.03g$ were fed a commercial diet with one of seven different daily feeding rates: 1.00%, 2.00%, 2.50%, 2.75%, 3.00%, 3.25%, and satiation (3.34%) based on body weight (BW). After four weeks of feeding, fish fed the 3% diet showed significantly higher weight gain (WG) and feed efficiency (FE) than fish that received the other feeding rates. In the second trial, the optimum feeding frequency was evaluated with three replicate fish groups averaging $2.04{\pm}0.03g$. Fish were fed a commercial diet at 2.87% BW with six different daily feeding frequencies: 2, 3, 4, 5, 7, or 9 meals. After four weeks of feeding, WG, specific growth rate, FE, and protein efficiency rate in fish fed 3 meals $d^{-1}$ were significantly higher than those of fish fed 7 or 9 meals $d^{-1}$. In both feeding trials, proximate composition of the entire body changed depending on the feeding rate or frequency. A broken-line regression analysis based on weight gain suggested that the optimum daily feeding rate and frequency for juvenile Korean rockfish at $15^{\circ}C$ was 2.9% BW $d^{-1}$ and 2-3 meals $d^{-1}$, respectively.

• Journal of Aquaculture
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• v.18 no.2
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• pp.98-106
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• 2005

A feeding trial of two extruded pellets (EPI, 45% crude protein with 7% crude lipid and EP2, 47% crude protein with 10% crude lipid)${\times}$ two satiation rates (satiation and 80% satiation)${\times}$ three feeding frequencies (three, two and one meal a day) factorial design with three replications was carried out to investigate the optimum feeding frequency and satiation rate for growth of juvenile flounder. Flounder averaging 55 g were fed a extruded pellets for 58 days. Daily feed intake was affected by dietary composition, feeding frequency and satiation rate (P<0.05). Weight gain of fish fed the EP1 and EP2 was not affected by both dietary composition and feeding frequency (P>0.05), but affected by feeding satiation rate (P<0.05). Weight gain of fish fed the each of EP1 and EP2 twice daily with satiation was the highest among treatments, but was not significantly different to that of fish fed the diets three times daily with satiation feeding. Feed efficiency and protein efficiency ratio of the fish were not affected by dietary composition, feeding frequency and satiation rate (P>0.05). Moisture, crude protein and crude lipid contents of the muscle of fish were affected by satiation rate. Moisture and crude protein contents of the liver were affected by dietary composition. Based on fish performance results, it can be concluded that the proper feeding frequency for the growth of juvenile flounder grown from 55 g to 90 g is two meals a day with satiation feeding, regardless of dietary composition used in this study.

• Korean Journal of Agricultural Science
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• v.46 no.3
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• pp.451-460
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• 2019

The aim of this study was to investigate the effects of dietary supplementation of acetaminophen on feed intake and growth performance of Hanwoo steers in the summer. Eight steers participated in a twelve-week experiment. The steers were randomly assigned into one of two treatments: Control and acetaminophen supplementation. Commercial acetaminophen was top-dressed to a concentrate mix at a rate of 3 g/kg based on dry matter. Individual feed intake was measured daily during the entire period of the experiment, and the intake of forage and concentrate diet were measured separately. The body weight of the steers were measured every 4 weeks. During the experimental period, ambient temperatures were recorded using an automatic temperature and humidity recorder. Acetaminophen had no effect (p > 0.05) on body weight, average daily gain, dry matter intake (DMI) and feed conversion ratio. Numerically, total DMI and concentrate DMI in the acetaminophen treated group were 5.7% and 7.6% lower than those of the control group, respectively, and the daily gain was 9.7% higher. As a result, the feed conversion rate of the acetaminophen treated group improved by 17% compared to the control; however, it was not statistically significant (p = 0.237). The results of this study suggest that acetaminophen supplementation may reduce the feed conversion ratio of Hanwoo steers under high temperature stress. However, further studies are needed to confirm the optimal level of acetaminophen supplementation which has a significant effect on the intake and weight gain of Hanwoo steers in the summer.

• Journal of Biosystems Engineering
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• v.24 no.5
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• pp.425-430
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• 1999

Complex environmental control systems were developed, which control properly the pig's environment in windowless pig-housing based on the thermoregulatory behaviors of pigs and concentrations of noxious gases (CO2 and NH3). The this study was conducted to assess the performance of complex environmental control systems by raising weaned piglets and growing pigs under different seasonal conditions. Average daily gain of pigs in the experimental pig-housing was slightly higher than that of pigs in the conventional pig-housing. Average daily gain was not significantly different in winter and spring(P＞0.05), but was significantly different in summer(P＜0.05). Feed conversion rate of pigs in the experimental pig-housing was smaller than that of pigs in the conventional pig-housing. Feed conversion rate was not significantly different in environment for weaned piglets and growing pigs resulted in the improved daily gain, feed conversion rate, and carcass quality of the finishing pigs. These results showed that the performance of the complex environmental control systems in windowless pig-housing was excellent for weaned piglets and growing pigs.

• ALGAE
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• v.35 no.3
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• pp.277-292
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• 2020

Omega-3 fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are polyunsaturated fatty acids beneficial to human health. A limited number of microalgae have been used for commercial omega-3 production, which necessitates the identification of new microalgae with high omega-3 contents. We explored the fatty acid composition and EPA and DHA contents of the mixotrophic dinoflagellate Gymnodinium smaydae fed with the optimal algal prey species Heterocapsa rotundata. Cells of G. smaydae were found to be rich in omega-3 fatty acids. In particular, the DHA content of G. smaydae was 21 mg g^-1 dry weight, accounting for 43% of the total fatty acid content. The percentage of DHA in the total fatty acid content of G. smaydae was the highest among the reported microalgae except for Crypthecodinium cohnii. Moreover, to determine if the prey supply interval affected the growth rate of G. smaydae and its fatty acid content, three different prey supply intervals (daily, once every 2 d, and once for 4 d) were tested. Daily prey supply yielded the highest total fatty acid and DHA contents in G. smaydae. Furthermore, we successfully produced high-density G. smaydae cultures semi-continuously for 43 d with daily prey supply. During the semi-continuous cultivation period, the highest density of G. smaydae was 57,000 cells mL^-1, with an average growth rate of 0.7 d^-1. Taken together, the percentage of EPA and DHA in the total fatty acid content was maintained in the range of 54.2-56.9%. The results of this study support G. smaydae as a promising microalgal candidate for commercial DHA production and demonstrate that daily supply of prey can efficiently produce high-density G. smaydae cultures for more than a month.