• Korean Journal of Veterinary Service
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• v.34 no.2
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• pp.111-116
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• 2011

Artificial insemination (AI) of swine is a very useful reproductive tool and that offers convenience in the Korean swine industry. Since many viruses have been reported to be excreted through boar semen, we investigated the presence of antibodies and antigens against viruses causing reproductive failure in semen of boar in 349 semen samples collected from six Korean AI centers. Viral antigens were detected by polymerase chain reaction (PCR) or reverse transcription-PCR predominantly. The results was as follows. The major reproductive failure causing factor was porcine circovirus type 2 (PCV2), followed by porcine reproductive and respiratory syndrome virus (PRRSV) ($X^2$=166.64, P<0.001). PCV2 and PRRSV, Japanese encephalitis virus (JEV), encephalomyocarditis virus (EMCV) was detected in 73 samples (20.9%), 44 samples (12.6%), 4 samples (1.1%), 3 samples (0.9%), respectively and porcine parvovirus in one sample (0.3%) Classical swine fever virus (CSFV), bovine viral diarrhea virus and Aujeszky's disease virus (ADV) were not detected. Enzyme-linked immunosorbent assay was carried out in 111 serum samples from three AI centers. In most pigs, antibodies response was showed prominently in CSFV (105 sera, 94.6%) ($X^2$=82.580, P<0.001), followed by, in PRRSV (100 sera, 90.1%), PCV2 (92 sera, 90.1%), and PPV (8 sera, 82.9%). ADV antibody was not detected. Thus, the experimental results will be used for the base data, with respect to the state of viral stillbirth in general pig farms, as well as AI centers and breeding farms in Korea.

• Korean Journal of Agricultural Science
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• v.48 no.2
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• pp.251-264
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• 2021

Bovine respiratory syncytial virus (BRSV) and bovine viral diarrhea virus (BVDV) are the main viral contributors to bovine respiratory disease (BRD) with high mortality and morbidity. BRD control measures include vaccination that modulates immunological profiles reflected in blood cells, serum, and body secretions, such as milk. This study evaluated the immune responses to an inactivated BRD vaccine in lactating cows reared in a natural environment on a dairy farm. The cows were intramuscularly inoculated with the vaccine, and serum, blood, and milk were collected pre-and post-vaccination. Our study revealed a prominent increase in BRSV-specific antibodies both in serum and milk, while the change in BVDV-specific antibodies was insignificant. Serum interleukin (IL)-1β and IL-6 levels significantly decreased, but this change was not reflected in milk. Evaluation of pattern recognition receptors (PRRs) via RT-qPCR revealed downregulation of nucleotide-binding oligomerization domain 2 (NOD2). The concentrations of BRSV antibodies, BVDV antibodies, IL-2, and IL-17A in serum and milk were strongly correlated, implying a concurrent influence on both body fluids. Thus, immunological factors modulated as a result of vaccination generally measured in serum were reflected in milk, demonstrating the suitability of milk evaluation as an alternative approach for immunological observations. Furthermore, the correlation between BRSV antibodies and NOD2 and that between BVDV antibodies and toll-like receptor (TLR) 2, TLR3, TLR4, and TLR5 imply the possible role of PRRs for the assessment of the immune response developed in immunized cows reared on the farm.

• Journal of Veterinary Clinics
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• v.17 no.1
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• pp.52-56
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• 2000

The objective of this study was to compare occurrence of the shipping fever associated with vaccination and mass medication in Korean Native Cow. Lack of vaccination (Pasteurella haemolytica, infectious bovine rhinotracheitis, bovine viral diarrhea, parainfluenza 3, and bovine respiratory syncytial virus) and mass medication before and after transportation, 67% of gram-negative cocci were detected. However, with vaccination and mass medication, only 33% of Gram-negative cocci were detected. When antimicrobial susceptibility for the detected bacterium was tested, apramycin, ampicillin, amilacin, clindamycin, gentamycin, kanamycin, penicillin, and streptomycin were resistant, whereas tylocin, amoxicillin, linocospetin, nalidixic acid, norfloxacin, oxalinic acid, and cefotaxime were susceptible. Morbidity and average therapeutic effect were 33% and 1.0time with vaccination and mass medication and were 78% and 5.3 times without vaccination and mass medication, respectively. Therefore, the results suggest that shipping fever would be considerably decreased with vaccination including mass medication before and after transportation.

• Korean Journal of Veterinary Service
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• v.36 no.2
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• pp.105-110
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• 2013

Bovine viral diarrhea virus (BVDV) is very important disease in domestic and wild ruminants and has a world wide distribution. Cattle persistently infected with BVDV (BVDV-PI) are the primary reservoir for BVDV infection in Korean native cattle herds. The prevalence of cattle persistently infected with BVDV (BVD-PI) was determined using 4,260 heads from 29 Korean native cattle farms at 8 districts from 2011 to 2012. The sera and ear nothches were collected for each sample. We surveyed BVD-PI cattle using antibody ELISA and antigen capture ELISA for detection of antibody and antigen respectively. Three thousand seventy-six cattle (72.2%) were positive for BVDV antibody and a total of 27 BVD-PI cattle were found in 12 farms. 11 cattle (40.7%) out of the total 27 BVDV-PI cattle were six months old or under. The positive rate of BVDV antibody (83.2%) from 12 farms with BVD-PI cattle was higher than the positive rate of BVDV antibody (63.6%) from 17 farms without BVD-PI cattle.

• Journal of Microbiology
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• v.45 no.5
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• pp.431-440
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• 2007

A silkworm (Bombyx mori L.) extract known to contain naturally occurring iminosugars, including 1-deoxynojirimycin (1-DNJ) derived from the mulberry tree (Morus alba L.), was evaluated in surrogate HCV and HBV in vitro assays. Antiviral activity of the silkworm extract and one of its purified constituents, 1-DNJ, was demonstrated against bovine viral diarrhea virus (BVDV) and GB virus-B (GBV-B), both members of the Flaviviridae family, and against woodchuck hepatitis virus (WHV) and hepatitis B virus (HBV), both members of the Hepadnaviridae family of viruses. The silkworm extract exhibited a 1,300 fold greater antiviral effect against BVDV in comparison to purified 1-DNJ. Glycoprotein processing of BVDV envelope proteins was disrupted upon treatment with the naturally derived components. The glycosylation of the WHV envelope proteins was affected largely by treatment with the silkworm extract than with purified 1-DNJ as well. The mechanism of action for this therapy may lie in the generation of defective particles that are unable to initiate the next cycle of infection as demonstrated by inhibition of GBV-B in vitro. We postulate that the five constituent iminosugars present in the silkworm extract contribute, in a synergistic manner, toward the antiviral effects observed for the inhibition of intact maturation of hepatitis viral particles and may complement conventional therapies. These results indicate that pre-clinical testing of the natural silkworm extract with regards to the efficacy of treatment against viral hepatitis infections can be evaluated in the respective animal models, in preparation for clinical trials in humans.

• Journal of Veterinary Clinics
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• v.29 no.5
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• pp.377-383
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• 2012

Bovine diarrhea is a major economical burden to the bovine industry in Korea. Since multiple infectious agents can be involved in bovine diarrhea, differential diagnosis is essential for effective treatment. Therefore, a panel of two multiplex real-time PCR assays which can simultaneously detect six major bovine enteric pathogens [i.e., bovine viral diarrhea virus (BVDV), bovine coronavirus (BCoV), group A bovine rotavirus (BRV), Salmonella spp., Escherichia coli (E. coli) $K99^+$, and Cryptosporidium parvum] was developed and applied to test 97 fecal samples collected from cattle farms in Korea. In addition, microscopic examination was also preformed on the samples to detect Coccidium oocyst. The estimated sensitivity of the multiplex PCR was 0.1 $TCID_{50}$ for BVDV, BCoV and group A BRV, 5 and 0.5 CFU for E. coli $K99^+$ and Salmonella, respectively, and 50 oocysts for Cryptosporidium. The amplification efficiency of the multiplex PCR ranged between 0.97 and 0.99 for each pathogen. Among 97 samples, 36 samples were positive for at least one of the 6 major pathogens and 6 samples were simultaneously positive for 2 pathogens by the multiplex PCR assay. Coccidium oocysts were also detected in 48 samples, which were all collected from over 1 month old calves. In conclusion, the multiplex real-time PCR panel can be a useful tool for fast and accurate diagnosis of calf diarrhea associated with BVDV, BCoV, group A BRV, E. coli $K99^+$, Salmonella, and/or Cryptosporidium and Coccidium may be an important target which needs to be included in the multiplex PCR panel in the future.

• Korean Journal of Veterinary Service
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• v.42 no.4
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• pp.217-225
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• 2019

To detect Single nucleotide polymorphisms (SNP) markers associated with Bovine viral diarrhea virus (BVDV) and Bovine respiratory syncytial virus (BRSV) S/P ratio in Korean Holstein dairy cattle, Genome-wide association study (GWAS) was performed using Illumina BovineSNP50 Beadchip. The number of phenotype data and genotype data were 107, and 294. respectively. Phenotype data were collected for four periods (0 week, 1 week, 4 week, 24 week) after having vaccinated (0 week no vaccinated period). A total of 36,257 SNPs was remained after quality control had been done by PLINK. The result of GWAS showed 6 SNP markers (BTB-01704243, BTB-01594395, ARS-BFGL-NGS-118070, ARS-BFGL-NGS-111365, BTA-65410-no-rs, Hapmap38331-BTA-61256) under BVDV and 4 SNP markers (ARS-BFGL-NGS-109861, Hapmap53701-rs29017064, ARS-BFGL-NGS-71055, BTA-11232-no-rs) under BRSV. And also, 10 candidate genes found through 10 SNP markers (TBX18, CEP162, PAFAH1B1, METTL16, BRCA1, RND2, POLK, ENSBTAG00000051724, ADAM18, NRG3).

• Korean Journal of Veterinary Research
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• v.36 no.2
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• pp.395-403
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• 1996

Monoclonal antibodies(MAbs) against field isolates of the bovine rotavirus A strain(G6), V strain(G10) and reference I-801 strain(G8) were produced and characterized. Six MAbs(4C2, 4D9, 5E1, 5E7, 5D5, 3E4) against A strain had neutralizing activity and reacted only with the G6 bovine rotaviruses determined by fluorescence focus neutralization (FFN) test. Otherwise, five neutralizing MAbs(1G2, 2G6, 5E2, 5E12, 5H7) against I-801 strain neutralized the G6 and G8 bovine rotaviruses. Five non-neutralizing MAbs(5F12, 7F12, 5E11, 2A11, 2B12) were VP6-specific and cross-reacted with all bovine and porcine rotaviruses examined by fluorescence antibody(FA) test. None of the MAbs reacted with bovie viral diarrhea virus(BVDV) and bovine coronavirus(BCV) determined by FA and FFN test.

• Korean Journal of Veterinary Service
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• v.43 no.3
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• pp.113-128
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• 2020

For estimating the prevalence of bovine infectious disease agents, the pathogens were classified as follows: the digestive disease agents, respiratory disease agents, reproductive disease agents, and tick-borne disease agents. This study covered 81 published papers regarding bovine infectious diseases in Korea that determined the presence of diverse pathogens or the antibodies elicited by the infectious agents in cattle from 2010 to 2019. In total, 59,504 cows were involved in the papers reporting the causative agents in their cases. The disease prevalence for the digestive, respiratory, reproductive, and tick-borne cases was 9.0%, 13.4%, 10.4%, and 7.8%, respectively. Bovine viral diarrhea virus, Escherichia coli, Mycobacterium avium subsp. paratuberculosis, and Eimeria spp were more significantly prevalent in the cows under one-year age than over one-year age. Bovine viral diarrhea virus, Escherichia coli, Mycobacterium avium subsp. paratuberculosis, and Anaplasma spp. were more significantly prevalent in Hanwoo than dairy cattle. Coxiella burnetii, Neospora caninum, and Theilieria spp. were more significantly prevalent in dairy cattle than Hanwoo. Tick-borne disease agents were more prevalent in cows grazing than the case in housing. Our analytic data obtained from this study emphasize the need for more studies on the occurrence of these pathogens according to the breed, age, and the region, to come up with bovine infectious disease control measures in Korea.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2003.10a
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• pp.34-34
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• 2003

Classical swine fever (CSF) is a contagious disease of swine with serious economic losses in pig industry [1]. The disease is caused by CSFV which belongs to the viruses of bovine viral diarrhea (BVDV) and border disease virus (BDV) make up the Pestivirus genus within the family Flaviviridae [2]. Attenuated Korean LOM strains were used in Korea. For these reasons a practical approach for discrimination between vaccine and field strains is needed. Here, we described the deveopment of real-time RT-PCR to discriminate between vaccine strains and Korean field viruses of CSFV. (omitted)