• Korean Journal of Animal Reproduction
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• 제25권1호
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• pp.1-7
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• 2001

This study was to test whether in vitro matured Hanwoo oocytes can be successfully cryopreserved by a new vitrification procedure using MVC method. For the vitrification, oocytes were pretreated in 10% ethylene glycol (EG10) for 5~10 min, exposed in EG30 for 30 sec, each oocyte was individually put on the inner wall of 0.25 $m\ell$ straw, and then straws were directly plunged into L$N_2$. Thawing was taken by 4-step procedures 〔1.0 M sucrose (MS), 0.5 MS, 0.25 MS, and 0.125 MS〕 at 37$^{\circ}C$. In vitro developmental capacity (survival, cleavage ($\geq$2-cell) and blastocyst rates) in vitrified group was no significant difference compared to that in other treatment groups (exposed; 100.0, 74.4, 32.3% and control; 100.0, 78.3, 36.3%): high mean percentage of oocytes (91.2%) was survived, 69.4% of them were cleaved and 27.9% of cleaved embryos were developed to blastocyst. Especially, after transfer of in vitro developed embryos in vitrified group, four of six recipient animals were pregnant and three of them were ongoing-pregnant by manual palpation at 250 days after transfer. This result demonstrates that MVC method is very appropriate freezing method for the Hanwoo in vitro matured oocytes and that ovum bank can be maintained efficiently by MVC cryopreservation method.

• Korean Journal of Animal Reproduction
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• 제24권1호
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• pp.89-95
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• 2000

This study was to establish an effective dilution technique in a vitrification of bovine blastocysts for the field trial. For vitrification, blastocysts were exposed in glycerol (G) and ethylene glycol (EG) mixture in m-DPBS supplemented with 10% FBS. Blastocysts were first exposed to 10% (v/v) G for 5 min, and subsequently were transferred to 10% G plus 20% EG (v/v) for 5 min. Finally, embryos were transferred to 25% G plus 25% EG (v/v) for 30 see and were placed in nitrogen vapor for 3 min, and then were plunged into L$N_2$. At thawing, the straw containing blastocysts was placed in air for 10 sec, and then plunged into a water bath at $25^{\circ}C$ until all ice had disappeared. They were placed in $25^{\circ}C$ and 36$^{\circ}C$ water according to treatment group for different time. Also, in vitro survival was assessed by the re-expansion and hatched rates at 24 hand 48 h postwarming, respectively. The results obtained in these experiments were summarized as follows; 1) In the survival rates of vitrified bovine blastocysts according to different dilution time at thawing, the data of 1 min group (86.6, 56.6%) were higher than those of other treatment groups (2 min; 93.5, 35.4%, 2.5 min; 76.9, 30.7%, 3 min; 88.8, 36.1% and 3.5 min; 83.7, 8.1%). 2) When the in vitro survival of vitrified groups according to different developmental stage was examined at 48 h after thawing using 1 min dilution method, the hatching rates of fast developed embryos (expanded blastocyst: 81.3%: early hatching blastocyst: 86.2%) were higher than that of delayed developed one (early blastocyst: 46.6%). 3) In addition, when the in vitro survival of vitrified groups according to different embryo age was compared, the hatched rates at 48 h after thawing of Day 7 (66.6%) and Day 8 embryos (60.0%) were significantly higher than that of Day 9 embryos (22.7%) (P＜0.05). These results demonstrate that vitrified bovine IVM/IVF/IVC blastocysts can be successfully survived in vitro using one-step dilution (1 min) method.

• Korean Journal of Veterinary Research
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• 제29권2호
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• pp.109-114
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• 1989

The frequency of appearance of HI antibody against Japanese encephalitis virus was investigated over the three-year period 1982 through 1984. The sample population consisted of 1306 cattle in Saitama prefecture (located in central Japan), and 536 cattle in Kagoshima prefecture (located in southern Japan). During the study period, there was no significant difference in the average antibody-positive rate between cattle in Kagoshima (68.8%) and those in Saitama (65.5%). Variations in the monthly antibody-positive rate and mean monthly antibody titer in the Saitama cattle followed a mountain-like pattern with the peak observed during summer. In the Kagoshima cattle, both parameters also increased in summer and these increases persisted even in winter. The distribution of antibody-positive rate as a function of age ranged from 64.0% to 82.8% in Saitama, though no correlation was observed between these two factors. In the Kagoshima cattle, however, the antibody-positive rate increased with age as follows; the values averaged 29.4% in the one-year-old cattle group, 50.0% in the two-year-old group, 47.4% in the three-year-old group and 74.5% in the four-year-old group. There was no significant correlation between the mean antibody titer and age in either Saitama cattle (15.3~22.5) or Kagoshima cattle (20.0~32.3).

• Clinical and Experimental Reproductive Medicine
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• 제23권1호
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• pp.33-39
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• 1996

This objective of this experiment was to test the effect of EGF on GVBD and MII of nuclear maturation of pig immature oocytes in vitro. Experiment 1 examined to the effect of EGF on nuclear maturation of pig immature oocytes according to different maturational times. The percentage of GVBD of EGF 10mg/ml treated groups were significantly higher than untreated groups after 24hr (p < 0.001). Experiment 2 examined to the effect of duration of exposure of oocytes to EGF supplement in maturation medium. Nuclear maturation rates (M II) of EGF treated groups (during 0-24: 72.8% and 0-42hr: 84.8%) were significantly higher than 53.5 and 26.1% of EGF treated group (during 24-42hr) and untreated group (p < 0.001). Also, experiment 3 examined to the effect of EGF on nuclear maturation of CEOs or CFOs. Nuclear maturation rate (M II) 84.6% of EGF treated group of CEOs was significantly higher than 53.0, 27.6, and 44.2% of EGF treated group of CFOs and untreated groups of CEOs and CFOs (p < O.001). These results conclude that EGF alone can stimulate GVBD and M II of nuclear maturation in pig immature oocytes.

• BMB Reports
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• 제42권7호
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• pp.444-449
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• 2009

Different neurodegenerative disorders like prion disease, is caused by protein misfolding conformers. Reverse-transfected cytosolic prion protein (PrP) and PrP expressed in the cytosol have been shown to be neurotoxic. To investigate the possible mechanism of neurotoxicity due to accumulation of PrP in cytosol, a PrP mutant lacking the signal and GPI (CytoPrP) was introduced into the SH-SY5Y cell. MTT and trypan blue assays indicated that the viability of cells expressing CytoPrP was remarkably reduced after treatment of MG-132. Obvious apoptosis phenomena were detected in the cells accumulated with CytoPrP, including loss of mitochondrial transmembrane potential, increase of caspase-3 activity, more annexin V/PI-double positive-stained cells and reduced Bcl-2 level. Moreover, DNA fragmentation and TUNEL assays also revealed clear evidences of late apoptosis in the cells accumulated CytoPrP. These data suggest that the accumulation of CytoPrP in cytoplasm may trigger cell apoptosis, in which mitochondrial relative apoptosis pathway seems to play critical role.

• Journal of Dairy Science and Biotechnology
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• 제14권1호
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• pp.85-95
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• 1996

This study was conducted to obtain basic data about the effect of Lactobacillus delbruckii on the quality and preservability of the bread during bread making. The parameters measured to investigate the bread quality were water content, water activity, pH, hardness, shelf life and sensory evaluation. The results obtained were as follows : 1. During the storage period, moisture evaporated faster in normal bread than the sourdough bread(10, 30, 50%). 2. Normal bread showed 0.94 and sourdough bread resulted from 0.94 to 0.96 in water activity, 3. The concentration rate of sourdough and different dough method resulted in significantly difference value of pH in bread. As the sourdough concentration rate increased the pH changed from 5.5 to 4.5 in sponge dough method. However, the sourdough concentration rate increased, the pH dropped from 5.4 to 4.8 in the bread which made by straight dough method. 4. The normal bread showed tough texture than the sourdough bread as the storage period is extended. 5. As the ratio of sourdough increased, the pH became lower and the production of the off fiavor, the growth of mold delayed for one or two days when stored at 30$^{\circ}$C. 6. The bread with sourdough resulted in higher score than the normal bread by sensory evaluation. 7, The bread with 30% sourdough by straight dough method showed the highest score and the bread with 10% sour dough by sponge dough method resulted in the highest score by sensory evaluation.

• Journal of The Korean Society of Grassland and Forage Science
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• 제40권3호
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• pp.149-155
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• 2020

Cattle feeding in South Korea has been heavily dependent on domestically produced rice straw and imported grain. Around 42% of domestically produced rice straw is utilized for forage, and the remainder is recycled to restore soil fertility. Approximately 35% of round baleages were made with rice straw. However, higher quality hay is desired over rice straw. Due to increasing stockpiles of rice, there has been an economic burden on the government to store the surplus; therefore production of annual forage crops in rice fields has been further promoted in recent years. Hay import from the USA currently constitutes more than 80% of total imported hays. The main imported hays are alfalfa (Medicago sativa), timothy (Phleum pretense), and tall fescue (Festica arundinacea). The estimated forage required for cattle feeding was approximately 5.4 million MT in 2016. Domestically produced forage sates only 43% of that value, while low quality rice straw and imported hay covered the rest of demand by 33% and 20%, respectively. As utilization of domestically produced forage is more desirable for forage-based cattle production, long-term strategies have been necessary to promote domestic production of high quality baleage. One such strategy has been utilizing the fertile soil and abundance of fallow rice fields of western region of S. Korea to produce forage crops. Italian ryegrass (Lolium multiflorum) is the most successfully produced winter annual in the region and is approximately 56% of the total winter annual forage production. Forage sorghums (Sorghum bicolor), sorghum × sudangrass hybrids, and hybrid corn (Zea mays) produce a substantial amount of warm-season forage during summer. Produced forage has been largely stored through baleage due to heavy dew and frequent rains and has been evaluated according to S. Korea's newly implemented baleage commodity evaluation system. The system weighs 50% of its total grading points on moisture content because of its importance in deliverable DM content and desirable baleage fermentation; this has proved to be an effective method. Although further improvement is required for the future of forage production in South Korea, the current government-led forage production in rice fields has been able to alleviate some of the country's shortage for quality hay.

• Korean Journal of Food Science and Technology
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• 제9권4호
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• pp.264-270
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• 1977

In order to investigate the effect of dietary fatty acids on lipids metabolism in adipose pads and superficial pectoral muscle of chicks, the present, experiment was carried out using signle comb White Leghorn male chicks fed a fat-free diet and diets containing margaric, stearic or linoleic acids. Total lipids of tissues were extracted with a chlorofrom-methanol solution. The lipid components were fractionated by thin layer chromatography and the fatty acid distribution of lipid fractions was determined by gas liquid chromatography. The neck adipose pads contained 34-62% total lipids, in which triglycerides, were dominant, being 97-98%. Margaric, stearic and linoleic acids were distributed at a relatively high rate in the adipose tissue when the corresponding acids were fed, and margaric acid feeding lowered palmitoleic acid distribution and linoleic acid feeding elevated stearic acid distribution. The wet superficial pectoral muscle contained 1.3-1.7% total lipids, of which 77-79% was phospholipids and 11-13% was free cholesterol. When margaric acid was fed, margaric and heptadecenoic acids appeared in the muscle lipids. When linoleic acid was fed, this acid was significantly highly distributed in every muscle lipid fractions, whereas, when stearic acid fed no elevation of stearic acid distribution was observed. In the muscle phospholipids, oleic acid was significantly highly distributed in the stearic acid fed chicks, and the linoleic acid feeding signigicantly lowered the distribution value of palmitic and oleic acids, but elevated the distribution value of stearic acid. And the linoleic acid feeding lowered the distribution value of eicosatrienoic acid and elevated the distribution value of arachidonic acid.

• Journal of The Korean Society of Grassland and Forage Science
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• 제35권2호
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• pp.99-104
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• 2015

This study was conducted to evaluate on agronomic characteristics, dry matter (DM) and digestible dry matter (DDM) yields of summer sowing sorghum hybrids (Sorghum bicolor (L) Moench) at Seongju in Gyeongbuk from 2013 to 2014. The experiment was arranged in randomized complete block design with three replications. Sorghum hybrids were seeded $31^{st}$ of July, 2013 and 2014. Sorghum hybrids were harvested on $3^{rd}$ November, 2013 and $5^{th}$ November, 2014. The observed average heading date was October 5, 8 and 9 for Sordan79, Sprint and SX17 respectively. The DM yield of 'SX17', 'Sordan79', and 'Sprint' was 24.2, 23,9 and 23.4 ton/ha, respectively and DM yield of those were significantly higher (p<0.05) than other three cultivars in 2013. DM yield of 'SX17', 'Sprint' and 'Sordan79' was 20.8, 20.0 and 19.3 ton/ha, respectively and DM yield of those was significantly higher (p<0.05) than other three cultivars in 2014. The DDM yield of 'SX17', 'Sordan79', and 'Sprint' was also higher (p<0.05) than other three cultivars in 2013 and 2014. ADF content of sorghum hybrids was low, whereas DDM was high. The results of this study indicated that traditional sorghum-sudangrass hybrids ('SX17', 'Sordan79') and sudan grass-sudangrass hybrid ('Sprint') than late flowering sorghum-sudangrass hybrid ('PACF8350') and sorghum-sorghum hybrids ('SS405', 'Sugar grazer') would be recommended for DM and DDM yields in the southern Korea.

• Magazine of the Korean Society of Agricultural Engineers
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• 제13권3호
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• pp.2349-2371
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• 1971

1. The historical development of the agriculture in Korea is observed and the future of Korean agriculture is suggested with present situation in order to recommend a direction of policy in agricultural mechanization. 2. A factor analysis of agricultural mechanization The needs of agricultural mechanization in the view of both national need and the armer's desire under the present situation are analyzed with data from the various sources. The researcher found that the agricultural mechanization is badly needed to develop prospective Korean agriculture to future. 3. The direction of agricultural mechanization. It can be said that the position of agriculture in the national economy plays a very important role. This importance should not be ignored by the Politicians in their process of developing long range economy plan. The agricultural mechanization for the modernized Korean agriculture should be directed to increase the most effective results with minimize the least sacrifice. The merry tiller is recommended to the main agricultural machinery in Korea in order to meet its small farming operation un-its(or farm size). Tractor is recommended in the plain area for the crop cultivation. The cooperative cultivation for rice and the upland crops will be developed in the plain area. Tractor, therefore, is recommended for the main agricultural machinery in these areas. Either tractor or merry tiller is recommended to the orchard area by its operating size of the orchard. The researcher also disoussed about the development of animal husbandry on the farm with increasing the farm size in order to develop meadow and pasture nuder the consideration of both the improvement of food consumption and the comprehensive development of national resources. 4. Relationship between the Performance of various agricultural machinery and the economic scale. Because of the agricultural machinery needs an expensive fixed expense(fixed cost) the total expense Per ha of the fixed expense and the operation expense should less than the traditional expense Per Dan Bo with in creased corpgiclds Per Dan Bo. Since the anual fixed expense of the agricultural machinery is figured out by the durability the more the farm size the less fixed expense of machinery is required. The formula of this principle is as follows; fixed expense for Dan Bo=Fixed expense of agricultural machinery farm size(or farming scale) The breaking-even point is the balance point between the expense of the using agricultural machinery and the traditional farming expenses. Labor cost of the Dan Bo is increasing when the management scale increases by the tradititional farming while the machanized management decrease the management cost Per Dan Bo. The reseracher found that the distribution of agricultural machinery will be the adeventeous after the year of 1981 by the result of frguring out the breaking-even point. 5. The Investigate and the conclusion. The purpose of this study is found out the direction of agricultural machanization and the breaking-even point of various agricultural machinery, there for is found out effective of the using various agricultural machinery for Collection cutter, Binder, Footing thresser, Semi-power thresser, Power thresser, Combine, Power rice-Trans-Planter, etc.