• Asian-Australasian Journal of Animal Sciences
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• v.20 no.3
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• pp.405-411
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• 2007

Gal-13 is an antimicrobial peptide isolated from chicken intestine. Ninety chickens were randomly divided into two groups (45 chickens for each group) to determine the effect of oral administration of Gal-13 on the acquired immune response. The chickens in the first group were fed a diet without Gal-13 as the control, and the chickens in the second group were fed the same diet, except that Gal-13 ($1{\mu}g/ml$) was suspended in drinking water just after hatching. Samples of blood, thymus, bursa of fabricius and spleen were taken at day 1, 4, 7, 10 and 17. The chickens in both groups received infectious bursal disease virus vaccine at day 20, and then sera samples were collected for analysis at 14, 21, 28 and 35 days after vaccination. The results showed: (1) Gal-13 could enhance the content of immunoglobulin (Ig)G at the age of 4 to10 days (p<0.05) and IgM at the age of 4 and 10 days (p<0.05) in the serum; (2) In vitro experiments showed that Gal-13 (0.625-1.250${\mu}g/ml$) enhanced the proliferation of peripheral blood lymphocytes of the chickens stimulated by lipopolysaccharide (LPS) and concanavlin A (ConA). Compared to the control, Gal-13 (1 ${\mu}g/ml$) enhanced the proliferation of bursa lymphocytes at 17 days of age (p<0.01) and thymus lymphocytes at 7 days of age (p<0.01), but restrained lymphocyte proliferation in chicken spleen and differed significantly at day 10 (p<0.01); (3) Gal-13 enhanced infectious bursal disease virus antibody in sera of chickens 21 days after infectious bursal disease virus vaccine administration (p<0.05). These results suggested that Gal-13 could modulate adaptive immune responses of chickens.

• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.545-553
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• 1999

A 474-base pair segment covering the hypervariable region of VP2 gene from six Korean infectious bursal disease virus(K-IBDV) isolates(K1, K2, SH/92, 225, 269, 310) and one attenuated IBDV(DAE) were amplified using RT-PCR, sequenced, and compared with published sequences for IBDV. K-IBDV isolates(K1, K2, SH/92, 225, 269) and foreign very virulent(vv) IBDV strains had 94.93~100% amino acid sequence similarity. K-IBDV isolate 310 and other K-IBDV isolates had 84.31~86.07% amino acid sequence similarity. Attenuated strain(DAE), like other attenuated strain, has substitution at positions 279(D to N) and 284(A to T) as well as in the serine-rich heptapeptide region. Five K-IBDV isolates except 310 isolate share unique amino acid residues at positions 222(A), 256(I), 294(I) which are not present in other standard and attenuated strains. At the two hydrophilic region, K-IBDV isolates except 310 isolate had identical amino acids comparing with Belgium vv IBDV 894VB but had four amino acid substitutions comparing with Chinese vv IBDV F9502. The SWSASGS heptapeptide is conserved in all K-IBDV isolates. The sequence of K-IBDV isolate 310 was markedly different from other IBDV strains, evolving from a separate lineage than the others. By phylogenetic analysis, Five K-IBDV isolates except 310 isolate were categorized in one group with foreign vv IBDV isolates but K-IBDV isolate 310 was categorized in a separate group which was differentiated from other compared IBDV strains.

• Korean Journal of Veterinary Research
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• v.46 no.3
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• pp.235-248
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• 2006

The VP2 full gene of Korean infectious bursal disease virus(IBDV) strain, SH/92, three attenuated vaccine strains, Bur706, Bursine-2 and CEV/AC strains, were amplified by reverse transcriptase-polymerase chain reaction and sequenced and compared with published VP2 gene sequences of IBDVs. The VP2 nucleotide sequence similarity between SH/92 and three vaccine stains was 95.6~96.5% whereas the nucleic acid similarity among three vaccine strains was 97.5~98.5%. The amino acid sequence similarity of VP2 of SH/92 compared with three vaccine strains was between 94.4 and 97.6% while the amino acid similarity among three vaccine strains was between 97.4 and 98.4%. The amino acid similarity between SH/92 and classical virulent strain, 52/70 and STC strain was 96.4 and 96.5%, respectively. The serine-rich heptapeptide was conserved in CEVAC and Bursine-2 as well as SH/92 but not in Bur706. The phylogenetic tree developed from amino acid sequences showed that SH/92 was categorized with vv IBDVs(HK46, OKYM, KKI, UPM94/273, SH95) in one branch while three vaccine strains were catagorized with STC strain in the other branch.

• Korean Journal of Veterinary Research
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• v.36 no.4
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• pp.997-1005
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• 1996

For understanding the role of infectious bursal disease virus(IBDV) to the pathogenesis of necrotic enteritis due to Clostridium perfringens(CP), all 15 day-old chickens used were divided as the following groups; A and E group with the feeding of feed contaminated with CP, B group with oral adminstration of IBDV($50{\mu}l/head$, $10^{3.4}EID_{50}$ of $P_4$ strain) and simultaneously feeding of feed contaminated with CP, C group treated with IBDV alone, F group with the feeding of feed contaminated with CP at 3 weeks after oral inoculation of IBDV, D and G group with the feeding of normal feed as controls. In mortality, B group(30%) was not a difference compared to A group(20%)(p>0.05), but in the pathological lesions the former was more severe degree than the latter. The mortality of F group(70%) was a significant difference to those of A, B or E group (20%)(p<0.01). Also, showed much F group more marked lesions than A, B or E group. In the chickens occurred the death during the study, mean concentration of CP was reached at $10^8{\sim}10^9CFU/g$ in the intestinal contents. B group showed higher mortality and more severe pathological changes than A and E group. Consequently, the results in the study were confirmed that the IBDV could be a role as a enhancing factor in pathogenesis of necrotic enteritis due to CP under the field condition.

• Korean Journal of Veterinary Service
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• v.34 no.1
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• pp.19-29
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• 2011

Prevalence of major legal communicable diseases in chickens and ducks, which had occurred in Jeonbuk province from year 2004 to 2008. Total 283 farms 1,419,244 chickens and ducks have been affected by avian diseases. Specifically, fowl typhoid (FT) occurred in 92 farms 416,600 chickens, Marek's disease (MD) in 45 farms 145,563, duck virus hepatitis (DVH) in 31 farms 199,200, infectious bursal disease (IBD) in 27 farms 113,220, infectious bronchitis (IB) in 27 farms 280,300, low pathogenic avian influenza (LPAI) in 26 farms 78,495, avian mycoplasmosis in 16 farms 103,774, Newcastle disease (ND) occurred in 11 farms 61,052, avian encephalomyelitis (AE) in 7 farms 21,000, Pullorum disease (PD) occurred in 1 farm 40. According to total analysis about major legal communicable diseases, 1 species of first-class legal communicable diseases have occurred, 3 species of second-class and 6 species of third-class all adding up to 10 species. In the first-class diseases, Newcastle disease have occurred. Pullorum and fowl typhoid, duck virus hepatitis in the second-class have occurred and as third-class diseases, Marek's disease, Infectious bursal disease, Infectious bronchitis, avian mycoplasmosis, avian encephalomyelitis, low pathogenic avian influenza have occurred.

• Korean Journal of Veterinary Research
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• v.51 no.1
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• pp.37-46
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• 2011

Infectious bursal disease virus (IBDV) is a member of the Avibirnavirus genus of the Birnaviridae family which genome consists of two segments (A and B) of double stranded RNA. Segment A gene of KNU08010 isolate, which was isolated from a 15-day-old chicken flock in 2008, was sequenced and compared with other IBDV isolates including SH/92 strain, the first Korean very virulent (vv) IBDV isolate. The amino acid sequences of segment A gene showed that KNU08010 had 99.2% homology with SH92 strain. KNU08010 isolate had specific amino acids A222, I242, I256, I294 and S299 which are highly conserved among vvIBDV strains. Phylogenetic analysis based on the nucleotide sequences of variable region of the VP2 gene of 18 IBDV strains revealed that KNU08010 was grouped with vvIBDVs and was closely related to Korean vvIBDVs isolated from wild birds.

• Korean Journal of Veterinary Service
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• v.35 no.2
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• pp.91-97
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• 2012

The strategy for infectious bursal disease (IBD) control and its success rate under field conditions depends on hygiene management, IBD field pressure, level, and variation in maternally derived IBD antibodies. This study investigated the level of IBD-specific antibody by ELISA and the prevalence of IBD virus by PCR in broilers, white-semi broilers, and Korean native chickens raised in Jeongeup, Jeonbuk. IBD-specific maternally derived antibodies were measured from 698 chickens and the mean titers of maternal antibodies were $3,572{\pm}1,402$ in broilers, $1,262{\pm}762$ in white-semi broilers, and $1,932{\pm}912$ in Korean native chickens. At 2 weeks after vaccination, the geometric mean antibody titers of broiler, white-semi broiler, and Korean native chicken were $582{\pm}427$, $3255{\pm}1,080$, and $1,023{\pm}499$, respectively. According to sequence analysis of the variable virion protein 2 gene, 4 isolates were found to be very virulent IBDV, 9 isolates classical virulent, and 2 isolates intermediate plus vaccine strain.

• Journal of Veterinary Science
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• v.22 no.3
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• pp.33.1-33.6
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• 2021

Very virulent infectious bursal disease virus (vvIBDV) causes high mortality in chickens but measures to reduce the mortality have not been explored. Chickens (8-9 weeks) were treated with 3 agents before and during vvIBDV inoculation. Dexamethasone treatment reduced the mortality of infected chickens (40.7% vs. 3.7%; p < 0.001), but treatment with aspirin or vitamin E plus selenium did not affect the mortality. The bursa of Fabricius appeared to have shrunk in both dead and surviving chickens (p < 0.01). The results indicate that dexamethasone can reduce mortality in vvIBDV-infected chickens and may provide therapeutic clues for saving individual birds infected by the virus.

• Korean Journal of Veterinary Service
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• v.22 no.1
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• pp.53-59
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• 1999

In a flocks of broiler, 29 days old, was submitted to Iksan-branch, Livestock Development and Research Institute of Chonbuk province. Grossly, their feathers were ruffled and multiful hemorrhage were presented in the thigh and pectoral muscles. There were multifocal foci on the liver surface and enlarged and edematous on bursa of Fabricius. The coagulative materials, which were blood-tinged, were filled in cecum, and Eimeria oocysts were detected in the cecal contents. Microscopically, macrogametes were noted in the cecum, degeneration and necrosis of lymphocytes in the medullary area of bursal follicles, and multifocal necrosis of hepatocytes. There were positive in the infectious bursal disease(IBD) through selologic test and Salmonella gallinarum were detected. This report is a mixed infection case of coccidium, IBD and fowl typhoid in a flocks of broiler.

• Korean Journal of Veterinary Service
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• v.21 no.3
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• pp.277-284
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• 1998

Serum samples were collected from 100 breeders and their progeny 600 broilers. The breeders and broilers were vaccinated against infectious bronchitis(IB), infectious bursal disease(IBD) and Newcastle disease(ND) viruses according to general vaccination program. The antibodies in serum samples against IB, IBD and ND viruses were detected by ELISA using commercial ELISA kit. Geometric mean titer(GMT) of ELISA was monitored from 1-day-old to 35-day-old broilers and compared to that of breeder chickens. The GMT of ELISA to IB, IBD and ND was declined half level of the day old broiler's antibody titers at about 4, 9 and 4 days of age. The GMT of ELISA to IB, IBD and ND was declined than that of protective antibody titer at about 12, 11, and 15 days of age. Thereafter, the GMT of ELISA to IB, ND were declined and disappeared according to age of broilers. The GMT of ELISA to IBD was declined according to age of broilers, but at 25 days of age increased and 31 days of age increased than that of protective antibody titer. Taken together, these studies led to conclusion that time-course of antibody titers of broilers from vaccinated breeders and that of progeny broliers which vaccinated according to vaccine program. Those are very important data to design vaccine program to breeders and broilers.