• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.639-643
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• 2002

Water quality, bacterial phase and fish growth rate were analyzed in the process of artificial seed production of flounder (Paralichtys oliraceus) larvae to investigate the water quality in rearing tank using Ultra Filtration System (UES). Sand Filtration System (SFS) and Ultra Filtration System (Ins) were set up in the experimental group. For the analysis of water quality, pH, salinity, DO, SS, COD, $NH_{4}^{+},\;NO_{2}^{-},\;NO^-,\;DIN$ (dissolved inorganic nitrogen) and DU (dissolved inorganic phosphate) were measured. There was no data difference between SFS group and UES group in most analysis items, but the UEs group showed low salinity and low 55 values, such that salinity was $33.5\%_{\circ}$ in SES group and $30.2\%_{\circ}$ in WS group and 55 was 15.5 mL/L in SES group and 7.0 mL/L for UPS group. For changes in bacterial phase and TBC (Total Bacterial Counts), in SES group, 6$\times$10^{5}CFU/mL in seawater decreased to the ratio of about 116, and TBC, Genus Vibrio and bacteria in the Genus Acinetobacter and Genus Micrococcus sharply increased after nine days, while stable bacterial phase was maintained low in UES group during the experiment except for Genus Ajteromonas. In the growth of the larvae, fish length was 17.0 mm (SGR 14.0) in the SES group and 18.8 mm (SGR 14.3) in the UFS group. It is concluded that when water is supplied for artificial seed production with WS, stabilization of water quality condition and inhibition of bacterial multiplication are possible. When production environment becomes stable, stable growth of fish becomes possible by reduction of environmental stress.

• Journal of Animal Environmental Science
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• v.16 no.3
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• pp.193-204
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• 2010

The goal of this study was to develop a high-rise hog building(HRHB) for growing-fattening stages. HRHB was two story building and was suitable for specific environment in Korea. Manure was treated in a first floor and pigs were raised on the slatted second floor. Three ventilation systems - 1) duct inlet to wall exhaust system(V1), 2) eave inlet to wall exhaust system(V2), and 3) ceiling inlet to wall exhaust system(V3) - were used. This experiment was conducted during winter and from summer to fall. Air temperature, air speed, ammonia, hydrogen sulfide in HRHB, and swine growth rate were measured. During winter, air temperature in V1 system tended to be slightly high without any effect of outside air temperature. Maximum temperature from summer to fall was between 33.4 and $33.8^{\circ}C$ and there was no significant difference among systems. Continuously measured daily temperature was lower in V2 system than other systems and the fluctuation of air temperature was high. Air speed in V1 and V2 systems were similar (0.02~0.21 m/s), and was 0.04~0.15 m/s in V3 during winter. From summer to fall, air speed in V1, V2, and V3 systems were 0.10~0.41 m/s, 0.10~0.83 m/s, and 0.11~0.26 m/s, respectively. V2 system showed bigger fluctuation of air speed than other systems. During winter, the highest concentrations of ammonia in V1, V2, and V3 systems were 7.0, 3.5, and 8.7 ppm, respectively. Hydrogen sulfide was not detected. The highest concentrations of ammonia from summer to winter in V1, V2, and V3 systems were 6.1, 2.8, and 5.6 ppm, respectively. Swine growth showed no statistical significance among systems. However, daily weight gain was approximately 4% higher in V1 and V3 than in V2. Feed intake/daily weight gain was approximately 4% higher in V1 than other systems. From summer to fall, daily weight gain in V1 and V3 tended to approximately 3% higher than other systems, and feed intake/daily weight gain was approximately 2% higher in V1 than other systems. Hence, V2 system for the ventilation system of HRHB should not be utilized.

• Korean Journal of Poultry Science
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• v.48 no.2
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• pp.91-100
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• 2021

The study determined the effects of stock density (SD) and energy level (EL) on growth performance, serum biochemistry, and meat quality in Korean native chickens. A total of 240 chickens were randomly assigned to one of the four treatments including two stock density (low, 14, and high, 16 chickens per m²) and two energy level (low, 2,950, 3,000, 3050 ME kcal/kg, and high 3,150, 3,200, 3,250 ME kcal/kg, for starter, grower, and finisher, respectively). During the whole period of the experiment, the chickens were fed ad libitum. The greater final body weight and weight gain were achieved in chickens fed high energy diet, whereas the final body weight and weight gain were significantly reduced in high-density treatment compared with the low density. Chickens in low-density groups had a higher feed intake compared with high-density treatment, however, the energy level did not affect the feed intake. An improved overall feed conversion ratio was detected in the high energy treatment. There was a significant interaction between stock density and energy level on cholesterol concentration. The concentration of aspartate transaminase in serum was increased by higher stock density. There was a significant treatment interaction on IgM levels. Moreover, the carcass rate was significantly increased in the high energy level treatment. Based on the findings, we suggest that rearing chickens in low density with high dietary energy levels could be beneficial by improving the growth performance.