• Korean Journal of Veterinary Research
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• v.32 no.1
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• pp.77-82
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• 1992

A noncytopathic bovine viral diarrhea virus(NC BVDV) strain isolated and purified from persistently infected primary bovine fetal lung(BFL) cells was studied by biophysical methods. The buoyant density of particles of the NC BVDV strain was shown to be between 1,090 and $1,114g/cm^3$ and the maximum virus infectivity occured at $1,098g/cm^3$. Immunoelectron microscopic examination by using the partially purified virus revealed regular spherical particles 30~80nm in diameter. Differences in the genomic size of cytopathic and noncytopathic BVDV from infected cells were not found. A comparison of viral proteins of a noncytopathic and cytopathic strain(NADL) by immunoprecipitation using monoclonal antibody indicated that NC BVDV, compared to cytopathic NADL, was cell associated.

• Korean Journal of Veterinary Service
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• v.47 no.2
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• pp.73-79
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• 2024

Bovine viral diarrhea virus (BVDV) is distributed in cattle worldwide and causes significant economic losses to the livestock industry. Identification and remove of BVDV persistently infected (PI) cattle is very important to control BVDV infection in cattle herd. The objective of this study is to investigate the infection status of BVDV infection in Korean native cattle (Bos taurus coreanae) farms located in Jeonbuk State. From 2021 to 2022, a total of 1,497 samples were collected from 17 cattle farms and tested for BVDV antigen using a commercial ELISA kit. By the first ELISA testing, 24 cattle from six farms were positive for BVDV antigen, showing the farm-level or cattle-level prevalence of 35.3% or 1.6%, respectively. By the second ELISA testing which carried out with the first ELISA-positive samples after three-weeks, 12 cattle (0.8%) from five farms (29.4%) were positive for BVDV antigen, indicating these cattle were PI cattle. Genotypes of BVDV were determined with 12 BVDV-positive samples using a previously described RT-PCR assay and the results showed that 3 (25.0%) and 9 (75.0%) were confirmed to be type 1 and type 2, respectively. These results will be helpful to establish the effective control strategy for BVDV in cattle farms in Jeonbuk State.

• Journal of Veterinary Clinics
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• v.29 no.5
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• pp.395-399
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• 2012

In 2011, several herds in Youngju city in Gyeongbuk province underwent an outbreak of bovine viral diarrhea virus (BVDV) causing high morbidity and mortality. Genetic analysis revealed that two subgenotypes of BVDV-1b (n = 21) and BVDV-2a (n = 7) were identified. The BVDV-1b subgenotype was most frequently detected from our field cases and BVDV-2a subgenotype was also identified in this outbreak. These BVDV-1b infections showed severe acute clinical manifestations similar to BVDV-2 infection. This result reports the detection of BVDV-1b associated with an acute and fatal outbreak of BVDV in Korean indigenous calves.

• Korean Journal of Veterinary Research
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• v.39 no.4
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• pp.743-750
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• 1999

Bovine viral diarrhea viruses (BVDVs) were isolated from cattle with respiratory and diarrhea signs as well as persistently infected cattle. These isolates were analysed serologically to characterize serogroups and to compare serological relationship with reference viruses of type I and II. Most isolates from calf diarrheal cases and persistently infected individuals showed a significant difference in cross-neutralization test with the viruses isolated from nasal discharges showing severe respiratory signs. Serologically most of the commercial vaccine strains could be classified into classical BVDV (type I) such as NADL strain. This serological difference among BVDV isolates suggested the need for new vaccines to protect cattle from both respiratory and enteric BVDV infections in field. The immunogenicity of BVDVs which showed a good propagation capability in MDBK cells and high rates of neutralizing activity (isolate : KD26-1, PHG, B5 and 95002) against all viruses used in this study, was confirmed in guinea pig when treated as single or combined groups.

• Korean Journal of Veterinary Research
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• v.32 no.3
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• pp.389-398
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• 1992

Molecular cloning was carried out on the Danish strain of bovine viral diarrhea virus(BVDV) to construct strategy for the diagnostic tools and effective vaccine of BVD afterwards. A recombinant DNA clone(No. 29) was established successfully from cDNA for viral RNA tailed with adenine homopolymer at 3'-end. $^{32}P$-labeled DNA probes of 300~1,800bp fragments, originating from the clone 29, directed specific DNA-RNA hybridization results with BVDV RNA. Recombinant DNA of the clone 29 was about 5,200bp representing 41.6% of the full length of Danish strain's RNA, and restriction sites were recognized for EcoR I, Sst I, Hin d III and Pst I restriction enzymes in the DNA fragment.

• Korean Journal of Veterinary Service
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• v.36 no.1
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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.

• Korean Journal of Veterinary Service
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• v.42 no.2
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• pp.117-120
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• 2019

Bovine viral diarrhea Virus (BVDV) infections cause respiratory, gastrointestinal, and reproductive problems, such as infertility, abortion, stillbirth, and sickly offspring. Many countries have reduced the economic damage through the application of different control programmes, and some have successfully eradicated BVD. Detection and elimination of cattle persistently infected (PI) with BVDV is important for BVD eradication because PI cattle are a main source of BVD transmission. In this study, the prevalence of Korean native cattle persistently infected (PI) with BVDV was investigated and determined in 49 farms with 3,050 cattle. The all samples were collected by ear notch sampling. Korean native cattle with initial positives on antigen-ELISA (Ag-ELISA) were sampled again after 3~4 weeks and cattle with second positives in both Ag-ELISA and immunohistochemistry (IHC) were identified as PI cattle. Among the 49 farms, 14 (28.6%) farms had at least more than one PI cow and 21 (0.69%) of 3,050 cattle were determined as PI cattle. As a result of this work, it is suggested that national BVD eradication program is required to reduce economic losses by BVDV infection in Korean cattle industries.

• Korean Journal of Veterinary Research
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• v.32 no.1
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• pp.83-90
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• 1992

Monoclonal antibodies against structural proteins of bovine viral diarrhea virus(BVDV) were derived by classical hybridoma techniques. These antibodies were characterized by serum neutralization, immunoblotting and immunoprecipitation. The neutralizing monoclonal antibody reacted with the 56kd to 54kd(M.W.) viral protein in western blotting and immunoprecipitation analysis. Although there was no neutralizing activity, another monoclanal antibody reacted with the 45kd protein by immunoprecipitation and with both the 45kd and 36kd proteins in immunoblotting analysis. respectively. Densitometer scanning of purified BVDV and the immunopreipitation of whole virus particles with neutralizing monoclonal antibody revealed the presence of more than twelve viral polypeptides. Although no possible precursor form of protein was identified with the neutralizing monoclonal antibody. the presence of intact virion was detected in the infected cell supernatant immediatelty after pulse labeling, indicating rapid translational processing as well as packaging of the virus. The partial peptide mapping of 45kd and 36kd proteins with Staphylococcus aureus V 8 protease showed that these two proteins are related.

• Korean Journal of Veterinary Service
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• v.39 no.1
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• pp.35-39
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• 2016

The purpose of this study was to survey on infection status of pathogens of diarrhea from Korean indigenous goat. A total of 800 fecal samples was collected from 50 farms from January to October 2015 and was tested by automatic biochemical machine and polymerase chain reaction (PCR). The overall detection ratio of bacterial pathogens was 22.4% and viral pathogens was 16.3%, respectively. The detection ratio of Escherichia coli (E. coli), Salmonella spp., bovine viral diarrhea virus (BVDV), rotavirus and coronavirus were 21.5%, 0.9%, 7.6%, 5.6% and 3.0%, respectively. In the rates of mixed detection, single was 78.2%, double 8.4%, triple 11.6% and quadruple 1.8% in each sample and 38%, 12%, 16%, 20% in each farm, respectively.

• Journal of Veterinary Clinics
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• v.39 no.1
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• pp.38-43
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• 2022

A 5-month-old Holstein downer calf was presented, and bovine viral diarrhea virus was detected in the feces and the cerebrospinal fluid. Combined treatment of recombinant bovine somatotropin (rBST) administration and standing rehabilitation had been performed for two months, and the calf could maintain the standing position for a while. However, the symptoms were not improved, and the calf died due to ruminal tympany and aspiration pneumonia. Megaesophagus, abomasal ulcer, and a normal-sized but softened cerebellum were observed in clinical necropsy. Improvement of symptoms was confirmed by rBST, but was not reached the complete recovery of gait and standing position.