• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.2
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• pp.115-122
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• 2000

This study was carried out to determine a fertilization rate for productivity and nutritive value improvement of silage corn, using two kinds of composts, and to examine the potential possibility of utilization as an organic fertilizer. The experiment was conducted on the field plot at Gongiam, Kwangju, Kyunggi-Do for 3 years, from 1996 to 1998, and arranged in split-plot design with three replications. The main plots were two kinds of composts such as swine manure fermented with sawdust (SMFWS) and swine manure fermented without sawdust (SMF). Subplots were the nitrogen fertilization rates (0, 100, 200, 300 and 400kgN/ha/year). The dry matter (DM) yield increased as the nitrogen fertilization rate increased up to a rate of 300 kg N/ha, but decreased at rate of 400 kg N/ha. Dry matter yield in SMFWS treatment was higher than that of SMF treatment, but there was no significant difference between SMFWS and SMF treatments. Net energy for lactation (NEI) and total digestible nutrients (TDN) in corn increased as the fertilization rate of SMFWS and SMF increased, and crude protein (CP) content increased by the fertilization of SMFWS and SMF. No difference of CP, NEI and TDN was found between SMFWS and SMF treatments.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.1
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• pp.17-22
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• 2005

This experiment was conducted to investigate the effect of seeding dates and rates on the productivity and nutritive value of hairy vetch(Vicia villosa Roth) at experimental field of Grassland and Forage Crops Division, National Livestock Research Institute, RDA, Suwon from 1999 to 2000. The experimental design was consisted of split-plot design with three replications. The main plot was seeding dates(25 Aug., 15 Sep. and 5 Oct.) and the subplot was seeding rates(20, 30 and 40 kg/ha). Late seeding dates increased the plant height and delayed the flowering stage as 1 or 2 days. The dry matter(DM) content was decreased with low seeding rates, and the trend was same in the all plots. Average crude protein(CP) content was $24.1\%$ and increased with delayed seeding date and lower seeding rate. The content of acid detergent fiber(ADF) and neutral detergent fiber(NDF) was increased with higher seeding rate, but seeding date did not affect. In vitro dry matter digestibility(IVDMD) of hairy vetch tended to decrease with high seeding rate, and total digestible nutrient(TND) did not show significant difference among seeding rates. Average relative feed value(RFV) of hairy vetch showed 140 which means very high quality. Dry matter and CP yield was decreased with delayed seeding date. The results of this experiments indicated that seeding in middle-August with 40 kg/ha would be recommended to produce the highest yield and quality f3r the cultivation of hairy vetch in middle part of Korea

• Proceedings of the Botanical Society of Korea Conference
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• 1999.08a
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• pp.83-90
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• 1999

Electron crystallography of two-dimensional crystalsand electron cryo-microscopy is becoming an established method for determining the structure and function of a variety of membrane proteins that are providing difficult to crystallize in three dimension. In this study this technique has been used to investigate the structure of a ~160 kDa reaction centre sub-core complex of photosystem II. Photosystem II is a photosynthetic membrane protein consisting of more than 25 subunits. It uses solar energy to split water releasing molecular oxygen into the atmosphere and creates electrochemical potential across the thylakoid membrane, which is eventually utilized to generate ATP and NADPH. Images were taken using Philips CM200 field emission gun electron microscope with an acceleration voltage of 200kW at liquid nitrogen temperature. In total, 79 images recorded dat tilt angles ranging from 0 to 67 degree yielded amplitudes and phases for a three-dimensional map with an in-plant resolution of 6$\AA$ and 11.4$\AA$ in the third dimension shows at least 23 transmembrane helices resolved in a monomeric complex, of which 18 were able to be assigned to the D1, D2, CP47 , and cytochrome b559 alfa beta-subunits with their associated pigments that ae active in electron transport (Rhee, 1998, Ph.D.thesis). The D1/D2 heterodimer is located in the central position within the complex and its helical scalffold is remarkably similar to that of the reaction centres not only in purple bacteria but also in plant photosystem I (PSI) , indicating a common evoluationary origin of all types of reaction centre in photosynthetic organism known today 9RHee et al. 1998). The structural homology is now extended to the inner antenna subunit, ascribed to CP47 in our map, where the 6 transmembrane helices show a striking structural similarity to the corresponding helices of the PSI reaction centre proteins. The overall arrangement of the chlorophylls in the D1 /D2 heterodimer, and in particular the distance between the central pair, is ocnsistent with the weak exciton coupling of P680 that distinguishes this reaction centre from bacterial counterpart. The map in most progress towards high resolution structure will be presented and discussed.

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.2
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• pp.97-104
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• 2006

This experiment was carried out to determine the effect of harvesting date on the forage yield and quality of different rye (Secale cereale L.) cultivars. The experiment was conducted in split plot design with three replications. The main plots consisted of two harvesting dates 20th and 30th April. The subplots consisted of five rye cultivars from different maturity groups such as 'Kodiak (Late)'. 'Koolgrazer (Early)', 'Danko (Late)', 'Homil22 (Medium)' and 'Olhomil (Early)' Dry matter (DM) contents of 17.8% at early harvesting were lower 2.2% than at late harvesting. But crude protein (CP) of 18.9% and total digestible nutrients (TDN) contents of 65.5% at early harvesting were higher 2.3% and 3.0% than those at late harvesting, respectively. There were significant differences in DM, CP and TDN contents among the rye cultivars tested (p<0.05). The contents of fiber components at early harvesting were lower than those at late harvesting. The acid detergent fiber (ADF), neutral detergent fiber (NDF), cellulose and acid detergent lignin (ADL) contents at early harvesting were lower than those at late harvesting, and hemicellulose contents at early harvesting was higher than that at late harvesting. The fiber component of early maturing cultivars such as 'Koolgrazer' and 'Olhomil' were higher than those of the others. Dry matter, CP, in vitro digestible dry matter (IVDDM) and TDN yields at early harvesting were lower than those at late harvesting, and the yield of early maturing cultivars were higher than those of the others. In this study, the results of this study indicate that forage production technology in combination with early maturing rye cultivar and late harvesting could enhance both production and quality of rye.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.10
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• pp.1474-1483
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• 2013

The objective was to evaluate the use of prediction equations based on the chemical composition of feedstuffs to estimate the values of apparent metabolisable energy corrected for nitrogen balance (AMEn) of corn and soybean meal for broilers. For performance and carcass characteristics, 1,200 one-d-old birds (male and female) were allotted to a completely randomised factorial $2{\times}8$ (two genders and eight experimental diets) with three replicates of each sex with 25 birds. In the metabolism trial, 240 eight-d-old birds were distributed in the same design, but with a split plot in time (age of evaluation) with five, four and three birds per plot, respectively, in stages 8 to 21, 22 to 35, and 36 to 42 d of age. The treatments consisted of the use of six equations systems to predict the AMEn content of feedstuffs, tables of food composition and AMEn values obtained by in vivo assay, totalling eight treatments. Means were compared by Scott-Knott test at 5% probability and a confidence interval of 95% was used to check the fit of the energy values of the diets to the requirements of the birds. As a result of this study, the use of prediction equations resulted in better adjustment to the broiler requirements, resulting in better performance and carcass characteristics compared to the use of tables, however, the use of energy values of feedstuffs obtained by in vivo assay is still the most effective. The best equations were: AMEn = 4,021.8-227.55 Ash (for corn) combined with AMEn = -822.33+69.54 CP-45.26 ADF+90.81 EE (for soybean meal); AMEn = 36.21 CP+85.44 EE+37.26 NFE (nitrogen-free extract) (for corn) combined with AMEn = 37.5 CP+46.39 EE+14.9 NFE (for soybean); and AMEn = 4,164.187+51.006 EE-197.663 Ash-35.689 CF-20.593 NDF (for corn and soybean meal).

• Earthquakes and Structures
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• v.10 no.1
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• pp.105-123
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• 2016

In this paper, using the probabilistic methods, the seismic demand of buckling restrained braced frames subjected to earthquake was evaluated. In this regards, 4, 6, 8, 10, 12 and 14-storybuildings with different buckling restrained brace configuration (including diagonal, split X, chevron V and Inverted V bracings) were designed. Because of the inherent uncertainties in the earthquake records, incremental dynamical analysis was used to evaluate seismic performance of the structures. Using the results of incremental dynamical analysis, the "capacity of a structure in terms of first mode spectral acceleration", "fragility curve" and "mean annual frequency of exceeding a limit state" was determined. "Mean annual frequency of exceeding a limit state" has been estimated for immediate occupancy (IO) and collapse prevention (CP) limit states using both Probabilistic Seismic Demand Analysis (PSDA) and solution "based on displacement" in the Demand and Capacity Factor Design (DCFD) form. Based on analysis results, the inverted chevron (${\Lambda}$) buckling restrained braced frame has the largest capacity among the considered buckling restrained braces. Moreover, it has the best performance among the considered buckling restrained braces. Also, from fragility curves, it was observed that the fragility probability has increased with the height.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.3
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• pp.178-184
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• 2019

The objective of this study was to evaluate the dry matter yield of (DMY) of Italian ryegrass (IRG) forage crop based on two seeding date (September 25 and October 2) in 2017 and 2018, and evaluation of the potential reason of DMY reduction in IRG cultivars grown at Chuncheon, South Korea. Three cultivars of IRG including Kowinearly, Kowinmaster and Hwasan 104 were used in this experiment. The experimental field was designed as a split-split-plot arrangement. The cultivars were harvested on April 26 before the heading stage of both years. In this study, no significant effect (p>0.05) of seeding date has been found on the DMY, whereas the cultivars and year showed a significant effect on the DMY (p<0.05). Except September 25 of 2017, Hwasan 104 indicated significantly lower (p<0.05) DMY than Kowinearly and Kowinmaster in all seeding periods. Though no significant difference (p>0.05) was observed for the DMY between the two seeding dates in 2018, but the DMY was significantly lower (p<0.05) than that of 2017. Lower crude protein (CP) content of Kowinearly was observed on the seeding date of October 2 of 2017, and also in both seeding dates on 2018 (p<0.05). No significant difference (p>0.05) was observed in acid detergent fiber (ADF) between the cultivars on both seeding dates and years. Similarly, no significant difference (p>0.05) was found in neutral detergent fiber (NDF) between the cultivars in 2017. However, Kowinearly showed higher NDF content as compared to Kowinmaster and Hwasan 104 on both seeding dates and years. The seeding date has no significant difference (p>0.05). Thus, considering the extent of DMY in both years, the mean minimum temperature during winter season could be the limiting factor for the DMY of IRG cultivars. However, based on this study, the seeding dates of September 25 and October 2 have no potential effect on the DMY. Thus, on the basis of the current DMY and forge quality parameters, the cultivation Kowinmaster is recommended in Chuncheon.

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.4
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• pp.207-214
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• 2006

The object of this experiment was to suggest the optimum utilization upon rye and hairy vetch crops in Daejeon area. The field trials were conducted from 2002 to 2004 at Chungnam National University in order to evaluate the dry matter yield and quality of rye, hairy vetch, and rye+hairy vetch mixtures. The experiment was designed with split plots (main plot : seeding rate as rye mono culture, hairy vetch monoculture, rye 80%+hairy vetch 20%, rye 60%+hairy vetch 40%, and sub plot : 4 cutting stages as boot, heading, anthesis, milk). The average DM yield for 2 years had a difference on seeding rate and harvesting stages. The DM yield of rye monoculture was higher than those of the other seeding rates. There were significant increases in advanced stages in all treatments. In chemical composition, they also had a difference on seeding rates and growth stages. Hairy vetch monoculture was higher in crude protein (CP) and dry matter digestibility (DMD), but lower in fibrous compound than those of the other seeding rates (p<0.01). The crude protein dry matter (CPDM) and digestible dry matter yield was higher in rye 80%+hairy vetch 20% mixture when it was harvested at anthesis to milk stages. The results of this experiment indicated that when it was harvested at anthesis to the milk stages, rye 80%+hairy vetch 20% mixture was more effective in enhancing the DM yield and forage quality in Daejeon area.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.3
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• pp.237-244
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• 2008

This study was conducted to investigate the effects of the cropping system of forage crops and application of cattle slurry on productivity of forage crops and soil fertility. The field experiments were conducted on the silt clay loam at Gongiam, Kwangju, Kyung-gi province in Korea for two years. This study was arranged in split plot design with three replicates. Main plots were the cropping systems, such as single crop and mixed crops. Subplots were the application rate of cattle slurry, such as 0, 150 and 300 kg N/ha. The yields of dry matter (DM) and nitrogen (N) were hardly influenced by the cropping system, whereas DM and N yields enhanced as increasing the rates of cattle slurry application (p<0.05). The contents of crude protein (CP) and total digestible nutrients (TDN) were hardly influenced by the cropping system, whereas CP content increased as increasing the rates of cattle slurry application (p<0.05). TDN was not differentially influenced by cattle slurry application. Neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents were hardly influenced by the cropping system and application of cattle slurry. Organic matter (OM) content in soil samples collected at the end of the experiment were remarkably higher than those in the beginning of the experiment. The OM content of soil was significantly increased by application of cattle slurry (p<0.05).

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.4
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• pp.579-587
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• 2013

A total of 288 crossbred (Duroc${\times}$Landrace${\times}$Yorkshire) growing pigs were used in two experiments to investigate the effects of adding ${\beta}$-mannanase to corn-soybean meal-based diets on pig performance and apparent total tract digestibility (ATTD). Both experiments lasted 28 d and were split into two phases namely 1 to 14 days (phase 1) and 15 to 28 days (phase 2). In Exp. 1,144 pigs weighing $23.60{\pm}1.59$ kg BW were assigned to one of four corn-soybean meal-based diets containing 0, 200, 400 or 600 U/kg ${\beta}$-mannanase. Increasing the level of ${\beta}$-mannanase increased weight gain (quadratic effect; p<0.01) and feed efficiency (linear and quadratic effect; p<0.01) during the second phase and the overall experiment. However, performance was unaffected (p>0.05) by treatment during phase 1. Increasing the amount of ${\beta}$-mannanase in the diet improved (linear and quadratic effect; p<0.05) the ATTD of CP, NDF, ADF, calcium, and phosphorus during both phases. Based on the results of Exp. 1, the optimal supplementation level was determined to be 400 U/kg and this was the level that was applied in Exp. 2. In Exp. 2, 144 pigs weighing $23.50{\pm}1.86$ kg BW were fed diets containing 0 or 400 U/kg of ${\beta}$-mannanase and 3,250 or 3,400 kcal/kg digestible energy (DE) in a $2{\times}2$ factorial design. ${\beta}$-Mannanase supplementation increased (p<0.01) weight gain and feed efficiency while the higher energy content increased (p<0.01) feed intake and feed efficiency during both phases and overall. Increased energy content and ${\beta}$-mannanase supplementation both increased (p<0.05) the ATTD of DM, CP, NDF, ADF, phosphorus, and GE during both phases. There were no significant interactions between energy level and ${\beta}$-mannanase for any performance or digestibility parameter. In conclusion, the ${\beta}$-mannanase used in the present experiment improved the performance of growing pigs fed diets based on corn and soybean. The mechanism through which the improvements were obtained appears to be related to improvements in ATTD.