• Journal of Biosystems Engineering
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• v.27 no.1
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• pp.11-18
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• 2002

One of the major obstructing factors against managing dairy farm in Korea has been a shortage of roughage supply, which resulted in excessive abuse of concentrate feed. In order to solve this problem, production of the wrap silage by the winter cereal forages raised in the fallow paddy field is strongly recommended in Korea. The main objective is to develop a tractor attached round bale wrapper which can process the silage by wrapping the round bales with thin plastic films. This is the first half of the study which is divided by two parts. In this first part, bale wrapping process was analyzed, and based on this results the followings were designed, developed and tested. 1. Bale wrapper which haying the maximum capacity of 1 ton bale with various functions such as loading, wrapping, discharging the round bales and supplying and cutting wrap films was designed. 2. An actuator and its hydraulic circuit of each process were developed and tested. 3. Also, the variations of hydraulic pressure and engine speed were investigated by operating bale wrapper developed. In this test, maximum pressure of the hydraulic circuit for the bale wrapping was 130 kg/㎠ when it raised the bale, which was quite below the relief pressure of 170 kg/㎠ of hydraulic circuit. In the engine speed test, speed drop was 20∼67 rpm, which meant that there was no over-load operation. Therefore, the experiment proved that developed hydraulic circuit and mechanism is stable in bale wrapping operation

• Journal of Biosystems Engineering
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• v.29 no.4
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• pp.293-300
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• 2004

In order to solve the shortage of roughage supply for dairy farm in Korea, the mechanized model system for the production of winter cereal wrap silage in the fellow paddy field was developed in the previous studies. In this study, storage properties after long term storing of the winter cereal wrap silage were investigated. Also, the qualities of the wrap silage which was stored during 4 months were evaluated by sensory testings, analyzing chemical properties(moisture content, pH and organic acids) and investigating the increase of feeding value. The result of this study were summarized as follows; 1. After 300 hours storage, the acid level of the silage decreased slowly to 4.6 -4.8 pH. Also, the temperature was stabilized around 27-28$^{\circ}C$. The silage having below 5.0 pH is a desirable level for the most of good silage. 2. According to the sensory test and chemical property analyzation it was evaluated as the first class silage like a com silage. 3. Also, when the wrap silage are fed to the cattle, the cattle produced milk more 25% than that of conventional feed. 4. As an overall conclusion, winter cereal wrap silage in the fallow paddy field cm be one of the major roughage source in replacement of com and other conventional silage to dairy cattle in Korea.

• Korean Journal of Poultry Science
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• v.10 no.1
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• pp.1-22
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• 1983

The Purpose of this study is to examine both supply and demand side of broiler chicken in Korea. Especially the paper aims to investigate the broiler chicken production Dressing and marketing pattern which may affect the demand for it. It is generally understood that broiler chicken production becomes unstable because of frequent market price fluctuation mainly due to disequilibrium of quantities demanded ana supplied It is important to point out that marketing in the form dressed chicken has been enforced by the regulation in Seoul area since March 1st, 1983, though live birds have been customarily marketed for year. It is assumed that the subsituation of chicken meat for beef would save foreign exchanges, because increasingly large amount of beef is imported mainly thanked to a chronical shortage in local production. Main findings of this study may be summarized as follows: 1) Broiler chicker production has been rapidly increased recently, estimating 180-200 million head per year with the trend of contineous increase year after year. Price fluctuation during the year is found, especially summer and winter mainly due to seasonal demand change. It is known that mal-funconing of broiler chicken market may be one of the causes for a large Price fluctuation. Accordingly the increase of marketing efficiency may reduce the price fluctuation and also positively impact on creating demand for the chicken consumption. 2) It is also interesting to note that 90 percent of broilers are grown on the floor and almost 86 percent of total broilers composed of so called high-bros, weighing on an average more than 1.6kg per head Approximately 8 weeks are required for of around marketing birds at the feed efficiency of around 2.3-2.5 Average broiler farm raises between 1,000 and 2,000 head, showing a quite small scale of operation. Only a few sampled farmers follow an all-in and all-out method in broiler production.

• Journal of Animal Science and Technology
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• v.63 no.5
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• pp.1064-1075
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• 2021

Recently, a high level of dietary crude protein (CP) has become of interest as a possible practice to improve the carcass quality of beef cattle, and its level has been increasing in the field. However, there is little scientific evidence that supports this. This study was conducted to test whether a high dietary CP level would improve growth performance, body metabolism, and carcass traits in Hanwoo beef cattle. A total of 32 Hanwoo finishing beef cattle (18 multiparous cows, six heifers, and eight steers) participated in a 12-weeks feeding trial. Two kinds of total mixed rations were prepared to contain two different CP; 156 g/kg for the control (CON) and 173 g/kg of CP for the treatment (HCP), while maintaining a similar level of metabolizable energy. The experiment was ended when more than half of the steers reached the target body weight (730 kg). Blood was collected at the end of the experiment. After harvesting, the carcass trait was evaluated at the slaughterhouse according to Korean standards. The carcass yield score and grade were also calculated based on revised criteria. Overall, dry matter intake, average daily gain, blood metabolites concentration, and the carcass traits, except for backfat thickness and the yield score, did not differ between the treatments. The HCP had lower backfat thickness than those of CON. There was no difference in the carcass yield grade, but the yield score was higher in the HCP treatment. According to the newly revised carcass grading criteria, both yield score and grade were higher in HCP than in CON. Increasing CP supply decreased the carcass's backfat thickness without altering growth performance and body metabolism, resulting in improved yield score and grade. Therefore, feeding a high CP diet may be beneficial in the farm income, although it may also increase feed cost and nitrogen excretion to the environment.

• Korean Journal of Veterinary Service
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• v.42 no.3
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• pp.127-133
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• 2019

The purpose of this study was to investigate the contamination level of representative mycotoxins that have adverse effects on livestock by using LC-MS/MS method and to utilize the results as basic data for the establishment of quality control system for feed, and to provide information on production and storage. A total of nine mycotoxins, including aflatoxin $B_1$, aflatoxin $B_2$, aflatoxin $G_1$, aflatoxin $G_2$, ochratoxin A, fumonisin $B_1$, fumonisin $B_2$, deoxynivalenol (DON), zearalenone (ZEN) were simultaneously analyzed in LC-MS/MS under ESI positive mode. Fumonisin $B_1$ and fumonisin $B_2$ were detected from 3 cases of 75 forage produced in Incheon area, the detection rate was 4.0%. The detection concentration was 0.01~0.02 mg/kg, which was lower than the domestic recommended limit. Fumonisins were detected in a slightly different manner from the results of mycotoxin studies reported in Korea, which is attributed to the high temperature and dry summer weather of the year. The result of LC-MS/MS method performance of 9 mycotoxins, the recovery of DON was quite low as $41.53{\pm}3.91%$ that is not suitable for simultaneous analysis. This is probably due to that the extract solution used in this study was not suitable for the extraction of DON, along with the characteristics of a very dry forage. For the study of mycotoxins in Incheon area forage for the first time, further investigation is needed for the safe supply of livestock products.

• Animal Bioscience
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• v.34 no.8
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• pp.1331-1341
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• 2021

Objective: This study aimed to determine the effects of replacing cassava chips with broken rice in a fermented total mixed ration diet on silage quality, feed intake, ruminal fermentation, growth performance, and carcass characteristics in the final phase of fattening beef cattle. Methods: Eighteen Charolais-Thai native crossbred steers (average initial body weight: 609.4±46 kg; average age 31.6 mo) were subjected to three ad libitum dietary regimes and were maintained in individual pens for 90 d before slaughter. The experimental design was a randomized complete block design by initial age and body weight with six replicates. The dietary regimens used different proportions of broken rice (0%, 16%, and 32% [w/w] of dry matter [DM]) instead of cassava chips in a fermented total mixed ration. All dietary treatments were evaluated for in vitro gas production and tested in in vivo feeding trials. Results: The in vitro experiments indicated that organic matter from broken rice was significantly more digestible than that from a cassava-based diet (p<0.05). Silage quality, nutrient intake, ruminal fermentation characteristics, carcass fat thickness, and marbling score substantially differed among treatments. The ruminal total volatile fatty acids, propionate concentration, dietary protein intake, and digestibility increased linearly (p<0.05) with broken rice, whereas acetate concentration and the acetate:propionate ratio decreased linearly (p<0.05) with broken rice (added up to 32 g/kg DM). Broken rice did not influence plasma metabolite levels or growth performance (p>0.05). However, the marbling score increased, and the carcass characteristics improved with broken rice. Conclusion: Substitution of cassava chips with broken rice in beef cattle diets may improve fattened beef carcass quality because broken rice increases rumen fermentation, fatty acid biosynthesis, and metabolic energy supply.

• Advances in nano research
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• v.10 no.1
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• pp.59-69
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• 2021

Electrospinning is a cost-effective and versatile method for producing submicron fibers. Although this method is relatively simple, at the theoretical level the interactions between process parameters and their influence on the fiber morphology are not yet fully understood. In this paper, the aim was finding optimal electrospinning parameters in order to obtain the smallest fiber diameter by using Taguchi's methodology. The nanofibers produced by electrospinning a solution of Thermoplastic Polyurethane (TPU) in Dimethylformamide (DMF). Polymer concentration and process parameters were considered as the effective factors. Taguchi's L9 orthogonal design (4 parameters, 3 levels) was applied to the experiential design. Optimal electrospinning conditions were determined using the signal-to-noise (S/N) ratio with Minitab 17 software. The morphology of the nanofibers was studied by a Scanning Electron Microscope (SEM). Thereafter, a tensile tester machine was used to assess mechanical properties of nanofibrous scaffolds. The analysis of DoE experiments showed that TPU concentration was the most significant parameter. An optimum combination to reach smallest diameters was yielded at 12 wt% polymer concentration, 16 kV of the supply voltage, 0.1 ml/h feed rate and 15 cm tip-to-distance. An empirical model was extracted and verified using confirmation test. The average diameter of nanofibers at the optimum conditions was in the range of 242.10 to 257.92 nm at a confidence level 95% which was in close agreement with the predicted value by the Taguchi technique. Also, the mechanical properties increased with decreasing fibers diameter. This study demonstrated Taguchi method was successfully applied to the optimization of electrospinning conditions for TPU nanofibers and the presented scaffold can mimic the structure of Extracellular Matrix (ECM).

• Design & Manufacturing
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• v.16 no.4
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• pp.67-74
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• 2022

Injection molding is a cyclic process comprising of cooling phase as the largest part of this cycle. Providing efficient cooling in lesser cycle times is of significant importance in the molding industry. Recently, lots of researches have been done for rapid cooling of a hot-spot area using CO2 in injection molding. The CO2 flows under high pressure through small, flexible capillary tubes to the point of use, where it expands to create a snow and gas mixture at a temperature of -79℃. The gaseous CO2 removes heat from the mold and releases it into the atmosphere. In this paper, a CO2 cooling module was applied to an injection mold in order to cool a large area cavity uniformly and quickly, and the cooling performance of the injection mold was investigated. The product was a high-curvature molded part with a molding area of 300x100mm. Heat cartridges were installed in a stationary mold, and CO2 cooling module was inserted inside a movable mold. Through structural analysis, it was confirmed that the maximum deformation of mold with CO2 cooling module was 0.09mm. A CO2 feed system with a heat exchanger was used for cooling experiments. The CO2 was injected into the holes on both sides of the supply pipe of the cooling module and discharged through hexagon blocks to cool the mold. It took 5.8 seconds to cool the mold from an average temperature of 140℃ to 70℃. Through the experiment using CO2 cooling module, it was found that a cooling rate of up to 12.98℃/s and an average of 10.18℃/s could be achieved.

• Korean Journal of Veterinary Service
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• v.45 no.4
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• pp.263-268
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• 2022

The current study examined the impact of fermented barley sprout extract prepared using lactic acid bacteria (Lactobacillus sp.) in decreasing odor and increasing livestock productivity and measured the difference in the polyphenol and flavonoid contents of the extract after fermentation. Furthermore, the effectiveness of fermented barley sprout extract was evaluated through order level and production index of livestock by supplying it to a broiler house. The results showed that with fermented barley sprout extract, the polyphenol and flavonoid contents were increased significantly by 174% and 562%, respectively. When the extract was applied as an additive to drinking water in the test farm, the productivity improved by about 10%, the mortality rate was reduced by about 66%, and there was a significant decrease in odor by about 80%. Compared with the control group, the production index increased by about 21%, the feed requirement decreased by about 8%, the odor showed a decrease in the NH₃ level, and no other gas was detected. It was observed that lactic acid bacteria settle in the intestine, suppress the proliferation of bacteria that cause diarrhea and enteritis, and help digestion. The lactic acid bacteria effectively remove bad odor gases such as NH₃, Amines, H₂S and CH₄S. Such odor reduction improves productivity. Our findings provide valuable information for quality water supply, production optimization and livestock management.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.294-294
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• 2022

In 2013, the Asian Development Bank classified the Philippines among the countries facing high food security risks. Evidence has suggested that climate change has affected agricultural productivity, and the effect of extreme climatic events notably drought has worsened each year. This had resulted in serious hydrological repercussions by limiting the timely water availability for the agriculture sector. Laguna is the 3^rd most populated province in the country, and it serves as one of the food baskets that feed the region and nearby provinces. In addition to climate change, population growth, rapid industrialization, and urban encroachment are also straining the delicate balance between water demand and supply. Studies have projected that the province will experience less rainfall and an increase in temperature, which could simultaneously affect water availability and crop yield. Hence, understanding the composite threat of climate change for crop yield and water consumption is imperative to devise mitigation plans and judicious use of water resources. The water footprint concept elaborates the water used per unit of crop yield production and it can approximate the dual impacts of climate change on water and agricultural production. In this study, the water footprint (WF) of six main crops produced in Laguna were estimated during 2010-2020 by following the methodology proposed by the Water Footprint Network. The result of this work gives importance to WF studies in a local setting which can be used as a comparison between different provinces as well as a piece of vital information to guide policy makers to adopt plans for crop-related use of water and food security in the Philippines.