• Korean Journal of Veterinary Research
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• v.22 no.2
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• pp.175-185
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• 1982

Since bovine lymphosarcoma causes considerable economic loss to the dairy industry, seroepidemiological survey on bovine leucosis virus (BLV) was carried out for the dairy herds throughout the country to observe the epidemiological situation of the disease by using immunodiffusion test. Attempts were simultaneously made to detect bovine leucosis virus in the lymphocytes from BLV antibody-positive cattle by means of fluorescent antibody techniques, syncytium assay and electron microscopy. In immunodiffusion test for BLV antibody in 2003 heads of dairy cattle selected randomly from 164 herds, the prevalence of positive reactors by regions were 37.8% in Central, 27.2% in Honam (Southwest), 28.0% in Youngnam (Southeast) and 25.2% in Youngdong (East coast)and averaging 29.7%. By provinces, Chungcheong appeared the highest prevalence of BLV antibody carriers (41.8%), while Jeonbug revealed the lowest incidence rate (24.4%). When the results of serological studies were analyzed by age groups and the sizes of herds, the number of reactors increased gradually with the advance in the age of cattle and the herd size. The highest rate of BLV carriers was found in the ages between 6 and 8 years, and in the size of herds with 20 to 50 heads. One hundred and seventeen breeding bulls from the central regions were tested for BLV antibody. Four out of 70 bulls (5.7%) of Korean cattle and 14 out of 39 bulls (35.9%) of Holstein were reactive for BLV antigens. Of 164 dairy herds examined, 17 herds (10.4%) have no BLV antibody-positive cattle, while 42 herds (25.6%) were included in the range of 20 to 40% of the positive rate and 10 herds (6.1%) in the range of over 80% of the rate. When the lymphocytes from the BLV antibody carrying cattle were cultured in the presence of phytohemagglutinin and stained with FITC-conjugated sheep anti-BLV serum, 8 out of 11 cases (72.7%) of BLV positive cattle revealed specific fluorescence for BLV in the lymphocytes. In syncytium assay of the peripheral lymphocytes of the cattle, 5 out of 7 (71.4%) lymphocytes from BLV antibody carriers induced syncytia in the indicators of bovine embryonic splenic cells. The cultured lymphocytes were examined with an electron microscope to detect the BLV particles. Two out of 6 specimens (33.3%) from the reactors showed the typical type C virus with the size of 90 to 110 nm around microvilli and in intracytoplasmic vacuoles.

• Journal of Animal Environmental Science
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• v.12 no.3
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• pp.107-114
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• 2006

This study was carried out to investigate the effect of new foot-bath facility and detergent solution (sodium molylbdenate, citrate, potassium nitrate, tataric acid, sodium hypo-cholorite, and zinc sulfate) on claw health in lactating dairy cows. Minimal inhibition concentration (MIC) and minimal bactericidal concentration (MBC) of copper sulphate were 0.31% for E. coli and Bacillus isolated from cows claw. The MIC and MBC of new detergent for E. coli were 1.25% and 5%, respectively, however their respectively values for Bacillus were noticed 0.63% and 2.5%. Both 5E. coli and Bacillus populations in petri-dishes were significantly reduced (more than 95%) with the application of new detergent solution (5% or 16%). Locomotion score (LS 1-5; very good to severely bad) of lactating cows were significantly improved with in 30 days with the use of new detergent solution in foot bath. The LS2 (n=16), LS3 (n=16), and LS4 (n=7) were shown 100%, 43.8%, and 14.3% recovery rate within 30 days with the use of new detergent solution. However, LS5 (n=2) were not recovered to normal claw health and locomotion score within 30 days of new detergent application. Usage of new detergent solution for 60 days in a foot bath have shown 81.3%, 71.4% and 50.0% recovery rate in cows with LS3, LS4 and LS5, respectively. Abnormal claw incidence was reduced from 18.8% to 1.5% in overall herd (n=80) with the use of new detergent solution (16%) in a foot bath for 90 days. In conclusion, usage of 16% of our detergent solution for 60 days in a foot bath can significantly improve the cow claw health and thus mitigate the negative effects of abnormal claw on productivity of cows and dairy farm income.

• Journal of Dairy Science and Biotechnology
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• v.32 no.2
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• pp.121-129
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• 2014

This study was carried out to investigate the quality characteristics of protein enriched fermented milk made with whey and soybean flour. Protein-enriched fermented milk was prepared as follows: Soybean flour was added before fermentation. No synthetic aroma was added. The fermentation starter culture was ABT-4 (Chr. Hansen). Whey protein was added after fermentation. Sensory evaluation indicated that sample containing soybean flour amount of 5% were better than other samples. The pH values and titratable acidities of stored protein-enriched fermented milk and fermented milk, respectively, were not remarkably different. Crude protein was more than 3 times higher in protein-enriched fermented milk (8.77%) than in fermented milk (2.49%). The crude fat content of protein-enriched fermented milk was not remarkably different compared to that of fermented milk. Dietary fiber was more than 2.7 times higher in protein-enriched fermented milk (1.67%) than in fermented milk (0.62%), and the free amino acid content was more than 14 times higher in protein-enriched fermented milk (37.9%) than in fermented milk (2.6%).

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.2
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• pp.203-211
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• 2020

Objective: Staphylococcus aureus (S. aureus) is one of the major microorganisms responsible for subclinical mastitis in dairy cattle. The present study was designed with the aim to explore the DNA methylation patterns using the Fluorescence-labeled methylation-sensitive amplified polymorphism (F-MSAP) techniques in a S. aureus-infected mouse model. Methods: A total of 12 out-bred Institute of Cancer Research female mice ranging from 12 to 13 weeks-old were selected to construct a mastitis model. F-MSAP analysis was carried out to detect fluctuations of DNA methylation between control group and S. aureus mastitis group. Results: Visible changes were observed in white cell counts in milk, percentage of granulocytes, percentage of lymphocytes, CD⁴⁺/CD⁸⁺ ratio (CD⁴⁺/CD⁸⁺), and histopathology of mice pre- and post-challenge with S. aureus. These findings showed the suitability of the S. aureus-infected mouse model. A total of 369 fragments was amplified from udder tissue samples from the two groups (S. aureus-infected mastitis group and control group) using eight pairs of selective primers. Results indicated that the methylation level of mastitis mouse group was higher than that in the control group. In addition, NCK-associated protein 5 (Nckap5) and transposon MTD were identified to be differentially methylated through secondary polymerase chain reaction and sequencing in the mastitis group. These observations might play an important role in the development of S. aureus mastitis. Conclusion: Collectively, our study suggests that the methylation modification in Nckap5 and transposon MTD might be considered as epigenetic markers in resistance to S. aureus-infected mastitis and provided a new insight into S. aureus mastitis research in dairy industry and public health.

• Journal of Life Science
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• v.19 no.9
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• pp.1258-1264
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• 2009

In this study, effects of feeding Holstein cows with TMR feed, which includes un-dried citrus byproducts, on the nutritional components of their raw milk were investigated. Two kinds of raw milk from primipara cows and multipara cows were used for the experiment: T0 (raw milk produced by dairy cows not fed with TMR feed including citrus byproducts) and T1 (raw milk produced by dairy cows fed with TMR feed including citrus byproducts). For both primipara and multipara cows, there was no statistically meaningful difference between T0 and T1 in terms of moisture, crude protein, crude fat, crude ash contents or caloric content. T1 showed a lower amount of cholesterol in raw milk for both primipara and multipara cows, which was especially statistically meaningful in multipara cows (p<0.05). Regarding mineral contents in raw milk, T1 showed significantly higher amounts of Na and S in primipara cows, and Na, Cu, Fe, S in multipara cows, respectively. For both primipara and multipara cows, there were no statistically meaningful differences between T0 and T1 in terms of the total amount of amino acids in the raw milk, the composition of saturated fatty acid/unsaturated fatty acid, vitamin A, E, $B_2$ or $\beta$-carotene, while T1 showed significantly higher levels of vitamin $B_1$ in primipara cows than T0.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.5
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• pp.723-728
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• 2009

In this study, the effects of feeding providing Holstein cows with with TMR feed including amended with undried citrus byproducts on the properties of their raw milk were investigated. Two samples were used for the experiment: T0 (raw milk produced by dairy cows fed with TMR feed not including citrus byproducts) and T1 (raw milk produced by cows fed with TMR feed including citrus byproducts). The All experiments were conducted with Holstein cows at a dairy farm in the on Jeju island, and were repeated three times, in each, after of which raw milk obtained from 7 cows of each samplein each group was analyzed[ED highlight - please ensure this is correct]. The daily milk yield and somatic cell numbers of T0 and T1 were 24.16 kg and 25.97 kg, and 660,000 thousands and 445,000 thousands, respectively, which means that feeding citrus byproducts to cows increases daily milk yield and reduces somatic cell numbers. There was were no significant differences between T0 and T1 in terms of the raw milk's total plate count, specific gravity, titration acidity, and or the amount of milk protein, lactose, nonfat solids, free amino acids and volatile compounds, while raw milk in T1 showed significantly lower levels of milk fat in raw milk. The antioxidant activity of raw milk was improved by citrus byproducts TMR feed containing citrus byproducts.

• Korean Journal of Poultry Science
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• v.42 no.4
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• pp.315-325
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• 2015

Recently, livestock breeding is more focused on the meat quality rather than meat quantity, mainly due to the improvement of consumers' income. Among the meat quality traits, meat color is one of very important traits because meat color is the first selection criterion from the consumers in the market. Most of the economically important traits have continuous variations and these are called quantitative traits. the genomic locations affecting these traits are called quantitative trait locus (QTL), which is mostly controlled by many genes having small effects. In this study, the recent QTL and candidate gene studies were reviewed in order to meet the consumers' demand for the future market. In the chicken QTL database, three traits are related with meat colors, namely breast color (Bco), meat color (Mco), drip loss (DL) and pH. The identified number of QTLs is 33 from 13 chromosomal regions. In these QTL regions, 14 candidate genes were identified; Eight for meat color (APP, BCMO1, COL1A2, FTO, KPNA2, PSMD12, G0S2, FTSJ3), two for drip loss (AGRP, FTO) and four for pH (GALNT1, PCDH19, DIAPH1, SPP2). These QTLs and candidate genes need to be confirmed and fine mapping is ultimately needed for identification of causative variations. The recently developed chicken resource population using Korean native chicken can be used for the improvement of meat quality traits, which increase the value that needed in the chicken industry.

• Journal of Dairy Science and Biotechnology
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• v.34 no.4
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• pp.231-237
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• 2016

Kefir is a probiotic food. Probiotics have shown to be beneficial to health, and are currently of great interest to the food industry. Hence, this study was carried out to evaluate the lactase activity of kefir-isolated lactic acid bacteria. Three strains, Lactobacillu kefiri DH5 isolated from the kefir grains and Bifidobacterium animalis subsp. Lactis and Bifidobacteria longum 720, commercial probiotic LAB, were fermented in 10% reconstituted nonfat dry milk suspensions and incubated at $37^{\circ}C$ for 48 h, and then analyzed for various saccarides by HPLC. The results showed that changes in the concentrations of lactose and galactose were significantly decreased and increased, respectively (p<0.05), but all 3 probiotic strains tested in this study showed no increase in glucose concentration during 48 h of incubation. Both DH5 and BL720 showed high lactase activities (p<0.05), whereas BLC exhibited the lowest activity. Additionally, all three lactic acid bacteria showed high tagatose, but did not show high xylose and sedoheptulose. Finally, DH5, a kefir-isolated LAB, may have similar characteristics and properties to typical Bifidobacterium spp. and showed higher lactase activity than commercial Bifidobacterium spp.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.7
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• pp.970-977
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• 2006

Forage oat (Avena sativa L.) is grown extensively in a double-cropping system on dairy farms. Four oat varieties ('Swan', 'Targa', 'Foothill', and 'Nugene') were evaluated for forage production and forage quality during two growing seasons (spring and autumn) at two locations (central and southern region) in South Korea. The heading stage of four oat varieties was observed during spring, but the autumn season did not produce heading until harvest time except for the 'Swan' variety (early-maturing variety). The heading stage of 'Swan' in both locations was earlier compared to other varieties. The four varieties were resistant to both foliar disease and insects. Lodging resistance was higher during autumn except in 2002 at the central region, and late-maturing varieties ('Foothill' and 'Nugene') have lower lodging resistance. Dry matter (DM) content was significantly different between varieties (p<0.001). Comparing different varieties, 'Swan', an early-maturing variety, was highest in DM content. In DM, total digestible nutrients (TDN) and crude protein (CP) yield, the yield of oat varieties in the southern region was higher than in the central region, and forage yield of the oat varieties in the spring season was higher than during the autumn season. The DM and TDN yield showed significant differences between oat varieties. The CP content of oats grown in the central region (Cheonan) was lower than oats grown in the southern region (Daegu), and the spring season produced oats with lower CP compared to the autumn season. Among the four oat varieties, the CP content of late-maturing varieties was higher than the Swan variety (early-maturing variety). The acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents were higher for the varieties grown in Cheonan and during the spring season. The ADF and NDF contents of late-maturing varieties were lower than the early-maturing variety. TDN and relative feed value (RFV) were higher for the varieties grown in Daegu and during the autumn season. Late-maturing variety had higher TDN and RFV than early-maturing variety. Our study showed differences in forage production and forage quality of oats grown in different locations, seasons and varieties. Forage quality as well as forage production was better in the southern region than in the central region. Forage quality was better during autumn, but forage production was better during spring. Late-maturing variety had better forage quality than the early-maturing variety. Therefore, late-maturing varieties are more suitable for use in the southern region.

• Journal of International Area Studies (JIAS)
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• v.18 no.3
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• pp.145-168
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• 2014

Given the distance from Mt. Baekdu, volcanic ash will have the direct impact on South Korea in case Mt. Baekdu erupts. Ash fall deposits or particulate matters(PM10) in the air will cause damages in various sectors. In particular, the PM10 impact on the manufacturing sector when the ash disperses in Korea is needed to be assessed since South Korea's manufacturing sector accounts for more than 30% of GDP. Meanwhile the economic impacts of PM10, including Asian dust, have been researched in Korea as the events become frequent, and losses in the manufacturing have been also reported. This study is to identify vulnerable sectors to volcanic ash in the korean industry, and to assess economic losses in case of a Mt. Baekdu eruption scenario, based on the historical loss experience with particulate matters. Study results show that airline, precision such as electronics and semiconductors, distribution, shipbuilding, car, leisure, glass, dairy farming are vulnerable to volcanic ash, or PM10. The economic losses in both car and shipbuilding industry is estimated to 46.49 billion Korean won due to shutdown for 6 hours in case of a Mt. Baekdu eruption scenario.