• 한국동물위생학회지
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• 제36권1호
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• pp.7-13
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• 2013

Bovine viral diarrhea virus (BVDV) is one of the most important disease viruses in cattle that can cause severe economical losses due to decreased fertility, abortion, diarrhea, and respiratory symptoms. Therefore, this study was aimed to investigate prevalence of BVDV infection (Transiently infection, Persistently infection) in dairy cattle in Gyeongnam southern area, Korea and use this data as the basis for establishing an eradication program and policy. A total of 44 bulk-tank milk samples (farms) collected in milk collecting center were tested for BVDV antibody using an ELISA. As the result, out of a total of 44 bulk-tank milk samples (farms), 38 (86.4%) samples were BVDV antibody positive. Blood samples (17 farms, n=543) were collected from BVDV antibody positive farms in bulk-tank milk, tested for BVDV antigen with ELISA and PCR. BVDV infected farms were 47% (8/17) and BVDV infected head were 2.2% (12/543). Persistently infected cattle (PI) were detected at 6 (35.3%) farms out of 17 farms and a total of 6 (1.1%) out of 543 head of cattle were identified as PI. The seropositive of BVDV antibody at farms and head were 100% (17/17) and 49.45% (91/184), respectively. The seroprevalence of BVDV antibody in PI infected farms (67.35%) much higher than that of BVDV antibody in transiently infected cattle (TI) infected farms (45%) and uninfected farms (34.48%). For eradication of BVDV infection in cattle populations, First of all, we should remove PI and need vaccination.

• 한국축산시설환경학회지
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• 제20권1호
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• pp.15-20
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• 2014

The present study was conducted to develop a milk filtering system for decreasing somatic cell count (SCC) in bulk tank milk. The pore sizes of the filter were 0.1, 0.3, 0.4, 0.5 and $0.8{\mu}m$. The rate of SCC reduction of $1^{st}$ grade milk on $0.1{\mu}m$ filter was 76% and significantly higher than other treatments. The rates of SCC reduction for 0.3, 0.4, 0.5 and $0.8{\mu}m$ were 35, 32, 18 and 6.4%, respectively. The effects of the milk filtering system on bacterial count and milk fat content were minimal. The milk flow rates per minute between the filter sizes were similar. But discharge pressures were increased as the pore size of the filter decreased. In conclusion, Considering the rate of SCC reduction, discharge pressure and cost, $0.4{\mu}m$ filter could be recommended.

• 한국동물위생학회지
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• 제44권1호
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• pp.27-33
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• 2021

Q fever is a worldwide zoonotic disease caused by Coxiella burnetii. Domestic ruminants are considered to be major source of human infection. The aim of this survey was to investigate seroprevalence of C. burnetii in ruminants in Gwangju area. A total of 1,000 samples (serum and lactoserum) were collected from 987 Korean native cattle, 5 Korean native goats, 2 beef cattle, 6 bulk-tank milk from each dairy farm in Gwangju area from January to October 2020 and analyzed by ELISA. The seroprevalence of C. burnetii in bulk-tank milk from each dairy farms was 50.0%. Korean black goat and beef cattle had negative antibody test results for C. burnetii. The seroprevalence of C. burnetii in Korean native cattle in Gwangju area was 7.1% and was higher in female (7.8%) than in male (3.4%) (P=0.024). The seroprevalence of C. burnetii in Korean native cattle appeared to increase with age (3.8% in 1 year-old, 7.1% in 3 year-old, and 10.7% in more than 5 year-old) (P<0.001). The seroprevalence of C. burnetii of Korean native cattle increased in spring and May was the highest in particular (P<0.001). As the distribution and density of tick-habitat are expected to increase due to climate crisis, this survey highlights the need for monitoring C. burnetii in domestic ruminants, including surveillance of C. burnetii infection in people working for livestock industry.

• 한국임상수의학회지
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• 제32권6호
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• pp.504-507
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• 2015

Coxiella burnetii는 세포 내 기생하는 리케치아의 한 종류로 전세계에서 발병하는 인수공통 전염병인 큐열의 원인체이다. 국내에서 C. burnetii의 감염이 사람과 동물에서 보고되고 있지만 제한적인 지역에서만 실시되었다. 본 연구의 목적은 real-time PCR을 이용하여 소의 혈액과 유즙 시료에서 C. burnetii의 전국적인 검출률을 조사하는 것이다. 총 1,325 개 시료(한우 혈액 622 개, 젖소 혈액 185 개, 젖소 개체 유즙 170 개 및 젖소 집합유 348 개)를 전국적으로 채취하였다. 채취한 시료에서 Genomic DNA를 추출하였으며 C. burnetii 검출을 위한 real-time PCR을 실시하였다. 한우 혈액 622 개 중 17(2.7%) 개에서 C. burnetii가 검출되었고 젖소 혈액 185 개 중 2 (1.1%) 개에서 C. burnetii가 검출되었다. 젖소의 개체별 유즙 170 개 중 27(15.9%) 개에서 C. burnetii가 검출되었으며 집합유 348 개 중 84(24.1%) 개에서 C. burnetii가 검출되었다. 본 연구는 국내의 소가 C. burnetii에 높게 감염되어 있는 것을 확인하였으며, 인수공통질병인 큐열에 의한 가축과 사람의 피해를 예방하기 위하여, 가축과 사람의 큐열에 대한 추가적인 역학적 연구가 필요하다고 생각된다.

• 한국동물위생학회지
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• 제45권1호
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• pp.39-45
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• 2022

The total bacteria count is significantly important factor for hygienic quality in raw milk. BactoScan FM^TM and BactoCount IBC^TM are the automated instruments for the determination of the total bacterial count in raw milk. They have been used after calibration by standard plate count (SPC) method in South Korea since 2000. It is necessary to re-evaluate for total bacterial counter according to the improvement of milk quality and the change of milk quality grade. Therefore, this study was evaluated the conversion mode of the two machines by SPC method. We collected 921 bulk-tank milk samples throughout the concentration range of 1,000~1,000,000 CFU/mL from June 2020 to October 2021. As a result, when compared by the SPC value, there was a slight difference in total bacterial count in BactoScan below 10,000 CFU/mL and above 200,000 CFU/mL and in BactoCount above 100,000 CFU/mL, respectively. Therefore, the conversion factor for BactoScan and the conversion equation for BactoCount were newly adjusted based on SPC value, and then the correlation coefficients (R²) was 0.85 or higher. In addition, the correlation (R²) between BactoScan and BactoCount was 0.91, which means the results were high positive correlation. These results are expected to contribute to improving the accuracy of the automated instruments for determining of total bacterial count in raw milk.

• 대한수의학회지
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• 제39권3호
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• pp.609-615
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• 1999

From July of 1997 to June of 1998, total 279 raw milk samples over withdrawal period after mastitis treatment from dairy farms located in the provinces of Kyonggi and Choongchung were collected to test drug residues. Each sample was tested by TTC- II test and Delvotest SP. Among the total 152 raw milk samples of cow treated by ${\beta}$-lactams, 32 samples(21.2%) were positive on the Delvotest and 15 samples(9.9%) showed positive on the TTC-II test. Also, from the total 37 samples treated by sulfonamides, 5 samples(13.5%) were positive on the Delvotest and 3 samples(8.1%) showed positive on the TTC-II test. For the total 55 raw milk samples of cow treated by tetracyclines, 9 samples(16.4%) were positive on the Delvotest and 5 samples(9.1%) showed positive on the TTC-II test. In addition, from the total 35 samples treated by aminoglycosides, 7 samples(20.0%) were positive on the Delvotest and 5 samples(14.3%) showed positive on the TTC-II test. Our study shows that it is possible that drugs are to be detected by the drug residues test of an individual raw milk even over the withdrawal period after mastitis treatment and the raw milk of bulk tank.

• 한국동물위생학회지
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• 제36권4호
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• pp.249-254
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• 2013

This study was done to determine the seroprevalence of Coxiella burnetii in cattle with reproductive disorders reared in eastern Gyeongbuk province. A total of 146 cattle blood samples from 83 farms in eastern Gyeongbuk province were collected in 2011~2012. Among them, 17 (11.6%) samples from 11 (13.3%) farms were seropositive for C. burnetii by ELISA. In dairy cattle with mastitis, 15 (38.5%) milk samples from 9 (42.9%) farms were seropositive among 39 milk samples from 21 farms. Among the seropositive farms, one farm with high seroprevalence was selected to assess the seroprevalence of C. burnetii in the bulk-tank milk (BTM) and blood samples of dairy cattle. The BTM sample from the farm was seropositive to C. burnetii and 6 (15%) out of 40 dairy cattle were seropositive. In cattle with reproductive disorders including infertility, abortion and stillbirth, 2 (1.9%) samples from 2 (3.2%) farms were positive among 107 samples collected from 62 farms. Among 2 positive samples, one of them is dariy cattle (100%) and the other is Korean cattle (0.9%) (P<0.001). This suggests that Korean cattle was relatively resistant to C. burnetii. Based on the data obtained, we identified association between C. burnetii shedding in milk and chronic subclinical mastitis in dairy cattle. Since seroprevalence of C. burnetii is relatively high in dairy cattle, further intensive studies on C. burnetii among the high risk milk farms and dairy cattle herds are needed to evaluate infection status.

• Asian-Australasian Journal of Animal Sciences
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• 제20권10호
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• pp.1525-1538
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• 2007

Because of the increasing evidence of potential benefits of conjugated linoleic acid (CLA) on human health, there is a need to investigate its status in commercial dairies and develop feeding strategies to enhance the content and supply of CLA in milk and milk products. A two-year experiment was conducted to study the status of milk fat c-9, t-11 CLA on four selected commercial dairy farms in Utah (two) and Idaho (two), USA. Farms A and C grazed cows on pasture and supplemented with 7.0 kg/cow per day of their respective grain mixes during summer, while conserved forage and grain mix was fed during winter. Farm B fed a total mixed diet all year, with 10% of diet dry matter as fresh cut pasture during summer. Farm D had 1/3 of its cows grazed on pasture and supplemented with a total mixed diet during summer, while the rest were fed a total mixed diet. All cows in Farm D were fed a total mixed diet during winter. Farms A, B, C, and D had on average 80, 400, 150, and 500 milking cows, respectively, with Holstein or its crosses as the major breed. On a year-round basis, Farms A and C produced milk with 60% or more milk fat c-9, t-11 CLA and transvaccenic acid (TVA) contents than Farm B. Similarly, Farm D produced 30% or more c-9, t-11 CLA and TVA in milk than Farm B. Milk fat content of CLA and TVA was 150-200% more during summer compared with winter. Individual cows varied from 0.16 to 2.22% in milk fat c-9, t-11 CLA contents and 89% of the cows had c-9, t-11 CLA contents between 0.3 and 1.0% of milk fat. Individual cow variation was larger on Farms A and C compared with Farm D, with least variation on Farm B. Variation was larger in summer than in winter. The bulk tank milk c-9, t-11 CLA content varied from 0.27 to 1.35% of milk fat. Cows on Farms A and C produced similar or higher amounts of milk fat c-9, t-11 CLA on a daily basis even though their milk yield was lowest among the dairies. Concentration and supplies of c-9, t-11 CLA and TVA were highest from June through September and lowest from February through April, which should be the months for targeting improvement in the content and supply of milk fat c-9, t-11 CLA and TVA.

• Asian-Australasian Journal of Animal Sciences
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• 제30권11호
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• pp.1643-1650
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• 2017

Objective: The control of psychrotrophic bacteria causing milk spoilage and illness due to toxic compounds is an important issue in the dairy industry. In South Korea, Gangwon-do province is one of the coldest terrains in which eighty percent of the area is mountainous regions, and mainly plays an important role in the agriculture and dairy industries. The purposes of this study were to analyze the indigenous microbiota of raw milk in Gangwon-do and accurately investigate a putative microbial group causing deterioration in milk quality. Methods: We collected raw milk from the bulk tank of 18 dairy farms in the Hoengseong and Pyeongchang regions of Gangwon-do. Milk components were analyzed and the number of viable bacteria was confirmed. The V3 and V4 regions of 16S rRNA gene were amplified and sequenced on an Illumina Miseq platform. Sequences were then assigned to operational taxonomic units, followed by the selection of representative sequences using the QIIME software package. Results: The milk samples from Pyeongchang were higher in fat, protein, lactose, total solid, and solid non-fat, and bacterial cell counts were observed only for the Hoengseong samples. The phylum Proteobacteria was detected most frequently in both the Hoengseong and Pyeongchang samples, followed by the phyla Firmicutes and Actinobacteria. Notably, Corynebacterium, Pediococcus, Macrococcus, and Acinetobacter were significantly different from two regions. Conclusion: Although the predominant phylum in raw milk is same, the abundances of major genera in milk samples were different between Hoengseong and Pyeongchang. We assumed that these differences are caused by regional dissimilar farming environments such as soil, forage, and dairy farming equipment so that the quality of milk raw milk from Pyeongchang is higher than that of Hoengseong. These results could provide the crucial information for identifying the microbiota in raw milk of South Korea.

• Journal of Animal Science and Technology
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• 제44권5호
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• pp.573-584
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• 2002

젖소의 에너지 및 단백질 영양상태를 평가할 수 있는 MP와 MUN을 측정하여 농장의 사료급여 실태를 평가하기 위해서 1999년 1월부터 2001년 12월까지 전국 4,856개 목장, 132,636두를 대상으로 유성분을 측정하였다. 조사된 개체유의 평균 MP와 MUN 수준은 각각 3.30${\pm}$0.35%와 16.0${\pm}$5.2mg/dl였으며, MP에 있어서는 3.10${\sim}$3.20%를 중심으로, MUN은 15.0mg/dl을 중심으로 하는 정규곡선을 나타내었다. 계절별 MP와 MUN의 수준은 외기 온도가 높은 하절기에는 MP의 함량이 3.2% 이하로 감소한 반면, MUN 수준은 16.5mg/dl 이상으로 가장 높았고, 반대로 동절기에는 MP가 3.35% 이상으로 가장 높았으며, MUN 수준은 15.0mg/ dl 이하로 가장 낮았다. MP 함량과 MUN 농도와의 관계에서는 MP가 정상 기준보다 낮은 2.90% 미만에서는 MUN 농도가 전체 평균보다도 높았고(17.3${\pm}$5.2mg/dl), MP가 정상 기준보다도 높은 3.70% 이상에서는 전체 평균과 비슷한 수준을 나타내었다. 개체유 및 집합유를 대상으로 MP 및 MUN 측정에 의한 사료내 에너지와 단백질 균형상태를 예측하였다. 그 결과 전반적으로 단백질은 부족보다는 과다가, 그리고 에너지는 과다보다는 부족이 많은 것으로 조사되었으며, 그 중에서도 비유초기에는 에너지 부족이, 비유말기에는 단백질 과다가 상대적으로 많은 것으로 조사되어 국내의 경우 무엇보다도 에너지 및 단백질의 균형적인 사료공급의 필요성이 제시되었다.