• Journal of Veterinary Clinics
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• v.1 no.1
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• pp.41-47
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• 1984

The author carried out bovine mastitis test by California Mastitis test(CMT) for the milk from dairy cows in the surburbs of Taejeon. In order to select prefer commercial therapeutic antibacterial agents for mastitis treatment, Staphylococcus aureus were isolated from the CMT positive milk and the strains were tested for the tolerance test to the agents. The results obtained were summarized as follows : 1. The tolerance test appeared graduate tolerance in cases with continuously repeat of therapeutic agents. 2. The antibacterial agents revealed strong tolerance were D-and E-ointments. 3. The antibacterial agents revealed suspect tolerance were A-and F-ointments and ampicillin, penicillin, kanamycin and streptomycin. 4. The antibacterial agents revealed non or rare tolerance were B-and G-ointments and chloramphenicol, erythromycin and oxytetracycline. 5, It is concluded that the use of 3-day-interval in turn with antibacterial agents selected by tolerance test may be beneficial.

• Korean Journal of Veterinary Service
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• v.23 no.4
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• pp.313-320
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• 2000

Staphylococcus aureus is a causative pathogen of bovine mastitis. It is recognized as a common pathogen in human and animal and specially enterotoxin-producing strain of S aureus is a common cause of staphylococcal food poisoning in human. Various food originated raw milk, cheese, butter produced from mastitic cow causes staphylococcal food poisoning. It is difficult to treat the staphylococcal mastitis because of increasing resistance by using overdose of antibiotics. This study was conducted to investigate the enterotoxin-production and coagulase serotypes of S aureus in Chonnam province for 6 month, 1999. Also we studied the antibiotic resistant pattern with 14 types against isolates. 18(10.1%) S aureus were isolated from 178 raw milk samples in seven farms. and 8 strains(38%) were isolated in 21 raw milk samples which was below 500,000 somatic cells. We identify that 7(87.5%) of 8 isolates and 15(83.3%) 18 isolates produce enterotoxin. Their enterotoxin serotype was type B(66.7%), type A(33.3%) and type C(13.3%). Also 2 strains of isolates was positive to the type A and B. Coagulase serotype of isolates was 2, 3, 4, 7, and 8. Most stains(70.6%) were serotype 2. And most strains(17 isolates, 94.4%) except one isolate was multiple resistant to the tested antibiotics.

• Korean Journal of Veterinary Research
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• v.51 no.1
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• pp.1-6
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• 2011

Sixteen steers were used to investigate the efficacy of the sustained-release implant of bovine somatotropin (bST) in improving growth and feed:gain ratio during 12 weeks. Administration of the 400 mg bST implant resulted in a 16.1% increase in growth rate, and this increase was significant (p<.05). The use of the sustained-release implant did not alter (p>.05) feed intake and feed:gain ratio. Thirty-four cows were used to investigate the efficacy of the sustained-release implant of bST in milk production during 4 weeks. Administration of the 200 mg bST implant resulted in an 8.7% increase in milk production, and this increase was significant (p<.05). Twenty-four barrows were used to investigate the efficacy of the sustained-release implant of porcine somatotropin (pST) in improving growth, feed:gain ratio and backfat thickness during 6 weeks. Administration of the 120 mg pST implant resulted in a 11.4% increase in feed:gain ratio and a 60% decrease in backfat thickness, and these results were significant (p<.05). But the use of the sustained-release implant did not alter (p>.05) growth rate and feed intake.

• Food Science of Animal Resources
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• v.21 no.3
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• pp.265-271
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• 2001

We investigated changes of immunoglobulin G (IgG) concentrations by heating and drying condition. Also it is performed to group for commercial product by promoting of IgG preservation and reducing of protein denaturation. The result was that content of IgG in colostrum was higher than normal milk. Especially, IgG content of colostrum within 12 hrs after parturition was over 44.67mg/ml and it is 60 times of normal milk. IgG contents was reduced rapidly according as passage of the time. IgG content of the sample heating at 30min at 65$^{\circ}C$ was still a little higher that heating for 10sec at 72$^{\circ}C$. IgG denaturation of heat treatment at 100$^{\circ}C$ for 10sec was lower than at 85$^{\circ}C$ for 30min. We investigated the changes of IgG concentrations of kinds of market milk different with heating processing. This result showed that IgG denaturation ratio by ultra high temperature pasteurization (UHT) was higher than long time low temperature pasteurization (LTLT). On the other hands, IgG content by spray drying was 14.5mg/g and freezing drying was 10.8mg/g. It showed that denaturation of protein content by freezing drying was more than spray drying.

• Korean Journal of Veterinary Research
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• v.49 no.3
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• pp.257-263
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• 2009

Bovine mastitis is an important disease causing serious economic loss in dairy production and food poison in public health. Escherichia coli and Staphylococcus aureus are the major causative agents of bovine mastitis. These bacteria were found in milk and environmental condition such as feces, water, soil and so on. Bovine mastitis causative micro-organisms can survive in 1-2 weeks in feces and bed complexes. Low level of percentage of water content (PWC) of feces and bed complexes can reduce the spreading of bovine mastitis incidence from environmental contamination. In this study, we developed the fecal dehydrating system and determined the elimination rates of bovine mastitis causative agent from feces and bed complexes. To develop the fecal dehydrating system, the screw pressurized dehydrating system was used and the maximum rate of dehydrating was reached to 52% PWC using 90% PWC (wet base) of fecal and bed complexes. The elimination rates of the dehydrating system for E. coli and S. aureus were reached at 41.19 $\pm$ 7.84% to 62.55 $\pm$ 8.71% in various percentages of PWC of feces and bed complexes (80, 85 and 90%). These results suggested that the application of fecal dehydrating system would reduce the exposure of dairy cattle to bovine mastitis causing agents contaminated feces and bed complexes, and can be used for environmental bovine mastitis control avoiding misuse or abuse of chemical disinfectants and antibiotics in dairy farm.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.432-434
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• 1989

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2004.10a
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• pp.45-45
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• 2004

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.10a
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• pp.297-301
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• 2005

• Journal of Veterinary Clinics
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• v.14 no.2
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• pp.349-351
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• 1997

7세의 홀스타인 암소에서 엽록소가 없는 Prototheca에 의한 만성적인 진행성 유방 염의 발생에 대해 보고한다. 유방염 우유로 만든 습윤표본에서 명확한 세포벽과 내생포자를 갖고 있는 구형 내지 난원형의 병원체가 직접 관찰되었고, Sabouraud배지에서의 순수배양물 에 대해 Wright염색 및 PHOL염색을 했을 때 algae가 증명되었으며, nutrient배지에서 세균 이 중식하지 않아서 Prototheca가 유방염의 원인으로 제시되었다. 이 병원체는 자연상태에서 는 사물기생성이지만 감염원은 확실하지 않았다. algae와 진균의 형태학적인 연구를 하는데 있어서 PHOL염색액을 광범위하게 응용할 수 있음을 제시하였다. Prototheca의 ecology와 병원성을 규명하기 위해 더 많은 연구가 이루어져야 될 것으로 생각된다.

• Journal of Food Hygiene and Safety
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• v.8 no.4
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• pp.215-223
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• 1993

Chloramphenicol (CAP) is a very effective broad-spectrum antibiotic which had been widely used in animal production. However, the drug is not approved in many countries for use in food-producing animals because of its potential toxicity and the possibility of residues in food products. In this study, a modified microbiological assay was developed for the sensitive detection of CAP residues in meat and milk. The method was characterized by the extraction of CAP with ethyl acetate, addition of $0.15\;\mu\textrm{g}$ oxytetracycline/ml in the phosphate buffer diluent (pH 6.0), a luteus ATCC 9341. The lowest levels of CAP detected in muscle tissues and milk were $0.025\;\mu\textrm{g}/ml\;and\;0.05\;\mu\textrm{g}/g$, respectively. Recovery rates free CAP from milk were 68.5%, from bovine muscle 65.1%, from swine muscle 63.8%, and from chicken muscle 59.4%, respectively, and the coefficients of variation were 1.8~15.1%. The results showed that the detection limits of CAP residues in animal products could significantly be improved by the modified microbiological assay than the conventional ones.