• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.4
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• pp.51-61
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• 2002

The objective of this study is to develop GLEANS-PADDY model to predict nutrients loading from paddy-field areas. This model is developed by modifying the GLEANS model which is used for uplands, and composed of hydrology and nutrient submodels. The optimal field size for CLEANS-PADDY model application is about up to 50 ha with mild slope, relatively homogeneous Soils and spatially rainfall, and a single crop farming. The CLEAMS model is modified to handle ponded soil surface condition and saturated soil profile in paddy field. In the hydrology submodel of the CLEAMS-PADDY model. the ponded depth routing method is used to handle the ponded water condition of paddy field. To compute potential evapotranspiration the FAO-24 Corrected Blaney-Criddle method is used for paddy field instead of Penman-Monteith method in the CLEAMS model. In the nutrients submodel of the CLEAMS-PADDY model, the soil was assumed saturated and soil profile in the root zone was divided into oxidized and reduced zones.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.657-666
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• 1999

The first option in manure management is developing an environmentally sound nutritional management. This includes proper feeding programs and feeds which will result in less excreted nutrients that need to be managed. Critical components that should be controlled are N, P and minerals that are used at supranutritional levels. Amino acid supplementation and protein restriction reduce N excretion in the monogastric animals. Supplementation with enzymes, such as carbohydrases, phytase and proteases, can be used to reduce excretion of nutrients and feces by improving digestibility of specific nutrients. Growth promoting agents, such as antibiotics, beta-agonists and somatotropin, increase the ability of animals to utilize nutrients, especially dietary protein, which results in reduced excretion of N. Some microminerals, such as Cu and Zn, are supplemented at supranutritional level. Metal-amino acid chelates, metal-proteinates and metal-polysaccharide complexes can be used at a much lower level than inorganic forms of metals without compromising performance of animals. Deodorases can be used to avoid air pollution from animal manure. Nutritional management increases costs to implement. It is necessary to assess the economics in order to find an acceptable compromise between the increased costs and the benefits to the environment and production as well.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.2
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• pp.250-257
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• 2001

An experiment was conducted to determine the effects of phytase supplementation to the diets containing different levels of non-phytate phosphorus (NPP). A $3{\times}2$ factorial arrangement of treatments was employed. There were three dietary NPP levels of control (C) (0.45% for starter diet and 0.35% for grower diet), C-0.1% NPP (0.35% for starter diet and 0.25% for grower diet), and C-0.2% NPP (0.25% for starter diet and 0.15% for grower diet) and two phytase levels (0 and 500 U/kg). Reduced dietary NPP decreased feed intake and weight gain and increased mortality whereas dietary phytase increased feed intake and weight gain and decreased mortality. Supplemental phytase improved availabilities of dry matter, crude fat, ash, P, Zn, Mg, and Cu whereas dietary NPP level did not affect availabilities of nutrients except decreased Zn availability and increased Cu availability in reduced NPP diets. Nutrient retention of N, ash, Ca, P, Mg, and Zn were linearly decreased as dietary NPP levels reduced but dietary phytase increased their retention. Reduced dietary NPP increased ash excretion but decreased P and Cu excretion while dietary phytase decreased N excretion. Weight, length, girth and contents of ash, Ca, P and Mg of tibia linearly decreased as dietary NPP levels reduced. Dietary phytase increased length and ash content of tibia. It is concluded that dietary phytase can reduce P excretion and alleviate adverse affects caused by feeding low dietary NPP. Effects of phytase were greater in the lower NPP diets.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.8
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• pp.1147-1152
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• 2005

Two experiments were conducted to evaluate the effects of dietary Biotite V (BV) supplementation on growth performance, nutrients digestibility and fecal noxious gas content in finishing pigs. In Exp. 1, a total of eighty pigs (initial body weight 88.0${\pm}$1.35 kg) were used in a 35-d growth trial. Pigs were blocked by weight and allotted to five dietary treatments in a randomized complete block design. There were four pigs per pen and four pens per treatment. Dietary treatments included: 1) Control (CON; basal diet), 2) 200 mesh BV1.0 (basal diet+200 mesh Biotite V 1.0%), 3) 325 mesh BV1.0 (basal diet+325 mesh Biotite V 1.0%), 4) 200 mesh BV2.0 (basal diet+200 mesh Biotite V 2.0%) and 5) 325 mesh BV2.0 (basal diet+325 mesh Biotite V 2.0%). Through the entire experimental period, there were no significant differences in ADG, ADFI and gain/feed among the treatments (p>0.05). With the addition of Biotite V in diet, DM and N digestibilities were increased significantly (p<0.01). Also, Ca and P digestibilities tended to increase in pigs fed Biotite V supplemented diet (p<0.01) compared to pigs fed control diet. Supplementation of Biotite V in diet reduced the fecal $NH_3-N$ and volatile fatty acid (VFA) compared to CON treatment (p<0.01). In Exp. 2, a total of sixty four pigs (initial body weight 84.0${\pm}$1.05 kg) were used in a 35-d growth trial. Pigs were blocked by weight and allotted to four dietary treatments in a randomized complete block design. There were four pigs per pen and four pens per treatment. Dietary treatments included: 1) LP (low protein diet), 2) HP (high protein diet), 3) LP+BV (low protein diet+325 mesh Biotite V 1.0%) and 4) HP+BV (high protein diet+325 mesh Biotite V 1.0%). Through the entire experimental period, ADG and gain/feed tended to increase in HP and HP+BV treatments, however, there were no significant differences (p>0.05) among the treatments. With the addition of Biotite V in diets, digestibilities of nutrients (DM, N, Ca and P) were increased significantly (p<0.01). The addition of Biotite V in diets reduced the ammonia emissions in feces (p<0.01). Supplementation of Biotite V in diets also reduced the fecal propionic acid, butyric acid and acetic acid (p<0.01) compared to pigs fed diets without Biotite V. In conclusion, supplementation of Biotite V can increase nutrients digestibility and reduce fecal $NH_3-N$ and volatile fatty acid (VFA) concentrations in finishing pigs.

• Journal of Nutrition and Health
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• v.37 no.1
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• pp.38-44
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• 2004

Food irradiation has been steadily increased in many countries concomitantly with increasing international trades and concerns about naturally occurring harmful contaminants of food. Although, irradiation provides an excellent safeguard for the consumer by destroying harmful bacteria, it would be necessary to investigate nutritional adequacy of irradiated foods with a special emphasis on such foods as red pepper powders, cold-water fishes (mackerel), sesame seeds that are widely consumed in Korea. These food items are of special concern due to the fact that most of them are imported and that several nutrients contained in them are sensitively reacting to irradiation. We observed changes in the antioxidant nutrients contents, such as vitamin A, $\beta$-carotene, vitamin C and total phenol, and also vitamin B$_1$ in the foods that were irradiated at different dose levels. The nutrients contents in red pepper were respectively 98.6% and 92.3％ for total phenol, and 97.8% and 94.5% for $\beta$-carotene, right after irradiation at the dose of 10 and 20 kGy. The vitamin C contents decreased with irradiation doses up to 76.4% (10 kGy) and 68.5% (20 kGy) and B$_1$ contents decreased to 54.9% and 80.7% of non irradiated red pepper. When the mackerel was irradiated at the applied dose of 3 and 7 kGy, total phenol concentration of the irradiated fish was respectively 91.3% and 94.2% of non irradiated fish. The amounts of vitamin A were 82.6% (3 kGy) and 78.0% (7 kGy) of unirradiated sample and vitamin B$_1$ contents reduced to 30.5% and 51.5%. $\alpha$-Tocopherol content was 33.9% of the non-irradiated one when it was irradiated at 7 kGy. Vitamin A and ${\gamma}$-tocopherol contents in sesame seeds linearly decreased with the applied doses (5 and 10 kGy) Vitamin A contents decreased up to 87.8% (5 kGy) and 82.9% (10 kGy) and that of ${\gamma}$-tocopherol were 72.4% and 66.5% of the unirradiated sample.

• Journal of the Korean Society of Food Culture
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• v.3 no.2
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• pp.197-206
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• 1988

Age, sex and the amount of activity determine recommended dietary allowances. So the method of developing RDA and their levels have been revised according as the physical condition of a nation improves and the amount of activity changes along with the variety of social situations. It can be seen from records that in Korea the absolute nutrient requirements for the people in Chosun Dynasty were first published in 1922. After that, in 1941 Gui Dong Han expressed his view that the standard health diets for the Japanese would be suitable for the people in Chosun Dynasty. In 1960, the temporary nutrition standards for the Koreans were established by the Ministry of the Health and Social Affairs. For these standards, males and females were respectively divided into three groups by age and nine nutrients were recommended for each group. In 1962, The Korean Association to FAO published the RDA for the Koreans. Since then, regular researches have been done. For these allowances, there were 16 age groups of men and women and ten nutrients recommended for each group. On the first revision in 1967, the fat allowance was presented at the ratio (12%) of fat calorie to total calories with no change in the number of age catagories and in the kinds of nutrients. And the basis of the riboflavin allowance was changed from the level of protein intake to that of energy intake. On the socond revision in 1975, there was brought 19 are catagories and ten nutrients recommended. On the third revision in 1980, age catagories increased to 22, and ten nutrients were recommended. On the fourth revision in 1985, there remained 21 groups by uniting the early and later periods of pregency. On the first revision in 1967, the recommended energy allowance was 3000 kcal, the highest level. Since then it has gradually been reduced. And it can be noticed that the protein allowance was high when food was difficult to obtain.

• Ocean and Polar Research
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• v.45 no.3
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• pp.103-111
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• 2023

To evaluate the impact of effluents from land-based fish farms on the coastal ocean of Wando, Korea, we analyzed inorganic nutrients, particulate organic carbon (POC), dissolved organic carbon (DOC), and colored dissolved organic matter (CDOM) in the effluent and influent of land-based fish farms during the summer (July) of 2021. The average concentrations of nutrients (Dissolved inorganic nitrogen, phosphorus, and silicate; DIN, DIP, and DSi, respectively) in the effluents of this study area were 17±3.7 μM, 1.4±0.7 μM, and 14±1.6 μM, respectively. The average concentrations of POC and DOC were 37±22 μM and 81±13 μM, respectively, with POC accounting for about 30% for total organic carbon in effluents. The Reduced Dissolved Inorganic Nitrogen/Total Dissolved Inorganic Nitrogen ratio (0.7), potential short-period index, indicates that the discharge of nutrients excreted by the fish and unconsumed feed into coastal water results in such nutrients being deposited and accumulated in the sediment. Subsequently, this continuous accumulation triggers the release of ammonium ions during organic matter decomposition, and the ammonium-enriched waters that encroach on fish farms as influent seem to be due to the diffusion of high concentrations of ammonium from bottom sediment. Furthermore, we used fluorescence indices to examine the characteristics of organic matter sources, obtaining mean values of 1.54±0.19, 1.06±0.06, and 1.56±0.06 for the humification index, biological index, and fluorescence index, respectively, in the effluent. These results indicate that the organic matters had an autochthonous origin that resulted from microbial decomposition, and such organic matters were rapidly generated and removed by biological activity, likely supplied from the sediment. Our results suggest that the effluent from land-based fish farms could be a potential source of deoxygenation occurrence in coastal areas.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.5
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• pp.763-769
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• 2020

Objective: The experiment was conducted to study the effect of rambutan (Nephelium lappaceum) fruit peel powder (RP) on feed consumption, digestibility of nutrients, ruminal fermentation dynamics and microbial population in Thai breed cattle. Methods: Four, 2-year old (250±15 kg) beef bull crossbreds (75% Brahman×25% local breed) were allotted to experimental treatments using a 4×4 Latin square design. Four dietary supplementation treatments were imposed; non-supplementation (control, T1); supplementation of RP fed at 2% of dry matter intake (DMI) (low, T2); supplementation of RP fed at 4% of DMI (medium, T3) and supplementation of RP fed at 6% of DMI (high, T4). All cattle were given a concentrate supplement at 1% of body weight while Napier grass was provided as a free choice. Results: The findings revealed that RP supplementation did not negatively affect (p>0.05) DMI of Napier grass, while RP intake and total DMI were the greatest in the RP supplementation at 4% and 6% DMI. Nevertheless, the nutrients (dry matter, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber) digestibilities were not changed in the RP supplementation groups. Rumen fermentation parameters especially those of total volatile fatty acids, acetate and butyrate were not significantly changed. However, the propionate concentration was remarkably increased (p<0.05) in the RP supplementation. Notably, the ratio of acetate to propionate, the number of protozoa, as well as the methane estimation were significantly reduced in the RP supplemented groups (4% and 6% of DMI), while the counts of bacteria was not altered. Conclusion: Supplementation of RP (4% of DMI) improved rumen propionate production, reduced protozoal population and methane estimation (p<0.05) without a negative effect on feed consumption and nutrients total tract digestibilities in beef cattle. Using dietary rambutan fruit peel powder has potential promise as a rumen regulator.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.3
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• pp.249-254
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• 1998

Two experiments were conducted to evaluate the effects of processing of barley on the growth performance and ileal and fecal digestibility of growing pigs. In Exp. 1, a total of 20 cannulated pigs (10.80 kg BW) were allotted to four treatments. Treatments were coarse ground barley as a control (CON), finely ground barley (FINE), extruded barley (EXT) and enzyme supplemented coarse ground barley (ENZ). In Exp. 2, a total of 100 growing pigs (36.50 kg BW) were allocated to the same treatments in completely randomized block design based on sex and body weight. In the first trial, pigs fed extruded barley showed significantly higher crude protein digestibility over pigs fed finely ground barley (p < 0.05). Pigs fed finely ground barley generally showed lower nutrients digestibility. Extrusion and ${\beta}$-glucanase supplementation showed a trend to improve nutrients digestibility. However, fine grinding rather reduced nutrients digestibility. The similar trend was found in the digestibility of essential amino acids. Fine grinding of barley significantly reduced amino acids digestibility. Extrusion and enzyme supplementation were found to improve amino acids digestibility of barley in growing pigs. In the growth trial, pigs fed extruded barley grew significantly faster than any other processed barley fed pigs. And extrusion of barley significantly improved feed/gain of pigs (p < 0.05). Fine grinding of barley and enzyme supplementation did not improve growth performance of pigs. In conclusion, fine grinding and enzyme supplementation does not appear to be an economical feed processing for growing pigs when barley is employed in the diets, while extrusion can be recommended as an effective feed processing technique for barley.

• Journal of Aquaculture
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• v.16 no.3
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• pp.171-178
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• 2003

Inorganic nutrients such as nitrogen and phosphate compounds accumulate in recirculating aquaculture systems. These nutrients must be removed from the system before they affect pH and fish health. For this purpose, aquatic plants are a simple and inexpensive method of removal. There are four commonly used aquatic plants: Eichhornia crassipes (water hyacinth), Pistia stratiotes (water lettuce), Hygrophila angustifolia, and Hydrocotyle leucocephala in freshwater recirculating aquaculture systems in Korea, but their efficiencies are not known. Therefore, removal efficiencies of inorganic nutrients from a freshwater recirculating aquaculture water with four commonly used aquatic plants were tested. Removing efficiencies of TAN, N $O_2$$^{[-10]}$ -N, and N $O_3$$^{[-10]}$ -N of the plants in 210 L aquaria for 48-hour period were tested. The removing efficiencies of TAN, N $O_3$$^{[-10]}$ -N, and P $O_4$$^{3-}$-P of the two most effective plants, water hyacinth and water lettuce, were also tested in 690 L (surface area of 1.55 $m^2$) tanks under 2 different initial stocking densities, 4 kg and 6 kg, for 22 days. Proximate analysis major nutrients and N and P contents of the all plants were analyzed for calculating net removal weight of N and P by the plants. Water lettuce was the most effective for removing TAN, N $O_2$$^{[-10]}$ -N, and N $O_3$$^{[-10]}$ -N from the water for 48-hour period tested followed by water hyacinth and Hygrophila angustifolia. Water lettuce reduced TAN, N $O_2$$^{[-10]}$ -N, and N $O_3$$^{[-10]}$ -N concentration from 2.3 mg/L, 0.197 mg/L, and 21.4 mg/L to 0.4 mg/L, 0.024 mg/L and 17.4 mg/L, respectively while water hyacinth reduced them down to 0.6 mg/L, 0.029 mg/L and 17.9 mg/L, respectively. The concentrations of TAN, N $O_2$$^{[-10]}$ -N, and N $O_3$$^{[-10]}$ -N in Hydrocotyle leucocephala group were rather increased up to 3.7 mg/L, 5.7 mg/L and 48.2 mg/L, respectively. This is because the creeping stem of Hydrocotyle leucocephala had to be cut to meet stocking weight resulting in decaying of the stem in the aquaria during experiment. The net growth in weight of water hycinth and water lettuce of 4 kg each in the 1.55 $m^2$ tanks for 22 days were 9.768 kg and 10.803 kg respectively, and those at initial weight of 6 kg each were 8.393 kg and 9.433 kg, respectively. The reason of lower net growth in the later group was restricted growth space. Nitrogen and phosphorus contents in water hyacinth were 2.89% and 0.27%, and those in water lettuce were 3.87% and 0.36%, respectively. Average quantities of removed N and P from 1.55 $m^2$ tanks by water hyacinth for 22 days were 18.9 g and 1.75 g, while those by water lettuce were 36.8 g and 3.5 g, respectively. Therefore water lettuce showed much higher efficiencies for removing both N and P from recirculating aquaculture water than water hyacinth.