• Korean Journal of Veterinary Research
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• v.14 no.1
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• pp.99-105
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• 1974

A total of 2,053 quarter milk samples of 518 dairy cows from 46 herds were examined for mastitis and results obtained were as follows: 1. A total of 428 quarters(20.8%) of 271 dairy cows(52.3%) from 41 herds(89%) were found to be infected with mastitis. 2. It was found that 71 quarters(3.5%) of 41 cows(7.9%) from 21 herds(45.6%) were clinical mastitis and 357 quarters(17.3%) of 230 cows(44.4%) from 20 herds (43.4%) were subclinical mastitis. 3. The main causative organisms of the mastitis were Staphylococcus aureus(26%), Streptococcus uberis(16%), and Streptococcus agalactiae(10%). 4. The majority of causative organisms were very resistant to colistin(85.9%), penicillin(67%), and streptomycin(39%). Most of the other drugs were highly effective as inhibitor for the most causative organisms in vitro. However sulfisoxazole was moderatively effective against them.

• Korean Journal of Veterinary Research
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• v.47 no.1
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• pp.67-75
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• 2007

Environmental mastitis has increased particularly in well-managed or low somatic cell countherds that have successfully controled contagious pathogens. Major pathogens of environmental mastitisare Escherichia coli (E. coli) and Streptococcus uberis. The present study was conducted to investigate1,865 quaters of 241 Korean dairy farms from 2001 to 2004. Prevalence of major gram-negative bacteriaisolated from mastitis milk were E. coli (22.7%) and Enterobacter spp. (16.3%) in coliforms and Pseudomoassp. (10.3%) and Serratia spp. (7.9%) in non-coliforms. The results on antibiotic susceptibility by agardifusion test against these pathogens were 86.7% in piperaciliin, 94.6% in cefepime, 85.5% in amikacin,87.7% in gentamicin and so on. In contrast, the susceptibility against ampicillin (41.9%), cephalothin (9.9%),streptomycin (39.9%) and tetracycline (46.7%) appeared to be below 50%. Gram-negative bacteria showed(96.8%). Acording to year, distribution of high $256{\sim}64{\mu}g/ml$ on cephalothin get increased, but the othersare diferent. These findings demonstrate that major gram-negative bacteria were E. coli and Enterobacterspp. isolates, and often encountered the diverse antibiotic resistant patterns.

• Food Science of Animal Resources
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• v.18 no.1
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• pp.9-18
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• 1998

This study was performed to obtain a large quantity of $\alpha$-lactalbumin ($\alpha$-LA) from milk by an improved separation and purification method. Functional properties-solubility viscosity, emulsifying activity, foamability surface hydrophobicity and gelation-of the purified $\alpha$-LA were investigated, $\alpha$-LA was purified in a large quantity by DEAE-Sephacel chromatography using 0.15M NaCl in 20mM Tris-HCl buffer(pH 7.2), as an eluent. The yield and purity of the purified $\alpha$-LA were 23.6%, 92.5%, respect-ively. The solubility viscosity and emulsifying activity of the purified $\alpha$-LA were 92.2$\pm$2% 3.46$\pm$0.19 cP and 345$\pm$5.0m^2$-/g respecively. The foamability of $\alpha$ -LA was 762 after 5min whipping which was lower than that of WPC and showed decreasing tendency with whipping time. The relative surface hydrophobicity of the $\alpha$-LA was formed when a 10% $\alpha$-LA solution containing 100mM NaCl and 20 mM $CaCl_2$ was heated at 92$^{\circ}C$for 40min. The $\alpha$-LA gel showed 31.5 as hardness and showed low springiness and cohesiveness.

• Food Science of Animal Resources
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• v.32 no.4
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• pp.389-395
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• 2012

Cloned animals are a result of asexual reproduction of animals using somatic cell nuclear transfer. Ever since the first report of a cloned sheep 'Dolly' produced by SCNT, increasing numbers of livestock, such as bovine and swine clones, have been generated worldwide. Foods derived from cloned animals have not been produced yet. However, the food safety of cloned animals has provoked controversy. The EU Food Safety Authority and U.S. Food and Drug Administration announced that milk and meat from cloned and non-cloned animals have no difference regarding food safety. However, food derived from cloned animals is considered unsuitable for eating vaguely. Moreover, there were scant information about cloned animals in Korea. Therefore, we surveyed the number of cloned animals worldwide including Korea and summarized the reports for cloned animals and discussed predictable problems.

• Journal of Veterinary Science
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• v.24 no.3
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• pp.42.1-42.6
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• 2023

Lumpy skin disease (LSD) is one of the most important emerging transboundary diseases. Recently, LSD has emerged in many countries in the northern hemisphere. The LSD virus has a huge genome and is highly resistant to environmental conditions. The virus is also host-specific and large ruminants, such as cattle and domestic water buffalo, are particularly susceptible. In addition, wild ruminants can serve as potential reservoirs for spreading the LSD virus. The emergence might be related to climate change in various regions because LSD is an arthropod-borne infectious disease. This disease causes enormous economic losses, such as leather damage, decreased milk production, abortion, and death in infected ruminants. The economic importance of LSD in the bovine industry has forced countries to develop and implement control strategies against the disease. With the recent global spread and the economic impact, LSD will be discussed intensively. In addition, effective preventive measures are suggested based on the presence or absence of LSD outbreaks.

• Korean Journal of Animal Reproduction
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• v.27 no.1
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• pp.9-14
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• 2003

The pBT-L transgenic mice carrying human TPO gene in conjunction with bovine $\beta$-casein promoter express human TPO in milk during lactation. In this study, stability of germ line transmission and expression of pBT-L transgene integrated into host chromosome were monitored up to generation F10 of transgenic pBT-L/15 line. When male mouse of generation F8 was crossbred with normal females, approximately half of offsprings (51.3$\pm$18.98%) were identified as transgenic mice. Generation F9 and F 10 mice also showed similar transmission rates (43.8$\pm$18.98% and 71.4$\pm$26.98%, respectively), implying that pBT-L transgene can be transmitted stably up to long term generation in the transgenic mice. Expression levels of human TPO from milk of generation F9 and F10 mice were 1.1$\pm$0.33 mg/ml and 1.1 $\pm$0.45 mg/ml, respectively, which are similar to expression level of generation F2 mice. In conclusion, our results suggest that transgenic animals once established will continuously pass their transgenes to the progeny through the breeding program with the same productivity of human protein in their milk.

• Journal of Veterinary Clinics
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• v.19 no.2
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• pp.228-235
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• 2002

Mastitis is the most costly disease results in lost milk production, decreased milk quality, milk discard, early culling of cows, drug costs and labor costs in dairy cow. Until now, a antibiotic administration at the end of lactation, dry cow therapy has been known the most effective and widely used mastitis control method. However, dry cow therapy do not control a new infection in the late dry and prepartum period because dry cow products have only persistent activity in the early dry period. Therefore, this study was conducted to evaluate clinical effect of sustained released biodegradable cephalexin microsphere using PLGA in bovine mastitis control during dry period. PLGA has been approved as controlled drug release system because of non-toxic, non-tissue reactive and bioerodible characteristics. This study revealed that cephalexin microsphere had a spherical shape with characteristic porous structure on the surface. Also, in vitro drug release studies are clearly observed that the release rate of cephalexin from PLGA microsphere decrease during the first 21 days after initial burst and then increase again between 3 and 4 weeks showing pulsatile releasing pattern. On the other hand, as tried in field the new infection rate, cure rate and mean SCC after parturition in cephalexin microsphere infused group were significantly differenced as compared to the control group. Accordingly, a sustained release of cephalexin from a biodegradable microsphere could make dry cow therapy more efficiently by preventing a new infection and decreasing the number of existing infection of mammary gland during dry period.

• Food Science of Animal Resources
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• v.26 no.1
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• pp.127-135
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• 2006

This experiment was carried out to examine the fermentation properties of yogurt with bovine milk and soybean milk at the mixed ratio of 2:1 and added 0.1, 0.2, 0.4 and 1.0% red ginseng extract. The effect on promoting the fermentation by additives 0.1, 0.2, 0.4 and 1.0% red ginseng extracts were higher and pH was $3.90{\sim}3.94$ when Lactobacillus acidophilus KCTC3150 and Lactobacillus salivarius ssp. salivarius CNU27 were used. Titratable acidity showed a little inhibiting due to increasing red ginseng extract content. The average viable counts of lactic acid bacteria after 15 hour culture was the highest level of $6.26{\times}10^8cfu/mL$ when Lactobacillus acidophilus KCTC3150 was used, and the additives content of red ginseng extract was 1.0% The production of lactic acid was the highest and the concentration was 332.22 mM when Lactobacillus acidophilus KCTC3150 was used, and the additives content of red ginseng extracts was 1.0% Lactose hydrolysis was completely hydrolyzed when Lactobacillus acidophilus KCTC3150 and Lactobacillus salivarius ssp. salivarius CNU27 were used. The highest viscosity of yogurt was 780 cP when Lactobacillus acidophilus KCTC3150 and Lactobacillus salivarius subsp. salivarius CNU27 were used and red ginseng extract was added 1.0% The overall acceptability, $4.17{\pm}0.64$, was the highest when Lactobacillus salivarius subsp. salivarius CNU27 was used and the additives content of red ginseng extract was 0.2%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.4
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• pp.390-397
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• 1992

This study was carried out to analyze the physicochemical properties of bovine milks, which were heated with LTLT, HTST, UHT pasteurization and UHT sterilization methods and to compare the heat intensity among the heating methods and samples. The mean HMF values per liter milk were measured as 0.66~1.62 $\mu$M (LTLT), 0.9~1.78$\mu$M (HTST), 3.53$\mu$M(UHT pasteurized) and 7.43~8.97$\mu$M (UHT sterilized) in samples, re- sportively. The available Iysine contents per 100ml milk showed 293.2 mg (Raw), 289.2~291.2 mg (LTLT), 298.4~292.4mg (HTST), 272.4~261.6mg (UHT pasteurized) and 279.0mg (UHT sterilized), respectively. The rates of whey protein denaturation were 9.5~11.4% (LTLT), 9.5~17.1% (HTST), 89.3~95% (UHT pas-tsterilized) and 62.7% (UHT sterilized), respectively. The contents of SH groups per g protein were determined as 2.86$\mu$M (Raw) and 2.95~3.15$\mu$M (LTLT), 3.08~3.18$\mu$M (HTST), 3.26~3.42$\mu$M (UHT Pasteurized) and 3. 36$\mu$M (UHT sterilized), respectively, The SS groups Contents per g protein were 28.93$\mu$M (Raw), 25.72~26. 51 $\mu$M (LTLT), 26.93~26.79$\mu$M (HTST), 23.65~23.04 $\mu$M (UHT pasteurized) and 24.69$\mu$M (UHT sterilized), respectively. The ascorbic acid contents per liter milk were measured 6.05mg (Raw), 1.47~1.65mg (LTLT), 2.50~3.85mg (HTST), 2.87~3.69mg (UHT pasteurized) and 4.50mg (UHT sterilized). The changes of some in-dices in milk samples depend on the heating temperature and time ; the HMF values, SH groups, whey protein denaturation rates increased, while the available lysine contents and SS groups decreased in LTLT, HTST, UHT pasteurized and UHT sterilized milks. No remarkable differences were found in heating indicators between LTLT and UHT milks.

• Korean Journal of Veterinary Research
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• v.37 no.2
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• pp.409-416
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• 1997

Bovine theileriosis caused by Theileria sergenti is the tick-borne intraery- throcytic piroplasmosis, that occurs in most regions of Korea. It results in severe economic losses on a farm caused by anemia, milk production loss, abortion and death. This study was undertaken to confirm the effects of the growth hormone and the insulin-like growth factor-I which are associated in the growth of cattle infected by T sergenti. The blood of one hundred and twenty ten-month Holstein was collected and the prepared blood smear was stained with acridine orange to investigate their parasitemia. And the hematological profiles were observed. According to the value of the hematocrit, they were categorized into four groups : Group 1 was under 20 percent, groups 2 and 3 were from over 21 to under 30 percent and from over 31 to under 35 percent and group 4 was over 36 percent. As the value of the hematocrit decreased, parasitemia(%) in erythrocytes was observed to increase(Y=-1.064X + 30.537, r=0.660). The amounts of the growth hormone and the insulin-like growth factor-I in the serum were measured by the radioimmunoassay. The growth hormone in serum of the group 1, group 2, group 3 and group 4 were observed as $0.238{\pm}0.043nmol/l$, $0.21{\pm}0.024nmol/l$, $0.366{\pm}0.035nmol/l$ and $0.646{\pm}0.223nmol/l$, respectively. The quantitative of the insulin-like growth factor-I in the same groups were observed also as $209.686{\pm}18.94ng/ml$, $250.9{\pm}12.609ng/ml$, $279.3{\pm}8.883ng/ml$ and $365.9{\pm}22.45ng/ml$, respectively. It can be concluded that the growth hormone and the insulin-like growth factor-I were observed to decrease in severe anemia due to theileriosis.