• Korean Journal of Veterinary Research
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• v.62 no.4
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• pp.29.1-29.7
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• 2022

Vaccination against Newcastle disease (ND) is the most effective means of controlling the disease, and these vaccines are commercialized only after their safety and effectiveness have been verified through tests that comply with Korean Standards of National Lot Release for Veterinary Biologics. This study investigated whether a relatively convenient and safe serological test can be used in place of the challenge test using highly virulent ND virus. Hemagglutination inhibition (HI) assay and enzyme-linked immunosorbent assay (ELISA) were considered positive of log₂ 2 or more and cutoff value of 200 or more, respectively, in both live and inactivated vaccines. However, when the antibody levels of the live and inactivated vaccines induced using the Ulster 2C, KBNP-C4152R2L, and K148/08 strains were compared, the antibody titers for inactivated vaccines were significantly higher than those for live vaccines in both the HI assay and ELISA. A strong positive correlation was observed between HI and ELISA antibody titers. The live vaccines corresponded to a survival rates of ≥ 80% and the inactivated vaccines corresponded to 100% survival rates. This study confirmed that standard efficacy tests can serve as serological tests, and can replace the challenge test and that the vaccine approval process can be improved.

• Korean Journal of Veterinary Service
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• v.27 no.3
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• pp.281-288
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• 2004

As all other intensively farmed domestic species, most mortality in ostriches is closely to rearing conditions. While ostriches is also highly sensitive to stress, species-specific infectious disease play only a minor role. But investigation of ostrich's disease is not peformed almost in Korea. The study was performed to investigate the titers of antibody for Newcastle disease(ND), Infectious bronchitis(IB), Egg drop syndrome '76(EDS), Avian influenza(AI), salmonellosis, Mycoplasma gallisepticum infection(MG), Mycoplasma synoviae infection(MS), Infectious bursal disease(IBD), Brucellosis, Toxoplasmosis, Japanese encephalitis(JE), Porcine parvovirus infection, Encephalomyocarditis and Porcine reproductive respiratory syndrome (PRRS). The results obtained in the 62 ostrich sera slaughtered in Gyeongbuk province were summarized as follows: The average of antibody positive rates to ND, IB, EDS, AI(H9Nl), JE, Porcine parvovirus infection and Encephalomyocarditis by HI test were $75.8\%,\;100\%,\;0\%,\;0\%,\;51.6\%,\;50\%\;and\;56.5\%$ respectively. The antibody positive rates to salmonellosis, MG, MS by plate agglutination test were $12.9\%,\;25.8\%,\;and\;0\%$ respectively. Antibodies to disease agent such as IBD and AI by agar gel precipitation(AGP) test, Brucellosis by tube agglutination, toxoplasmosis by latex agglutination test and PRRS by IFA were all negative.

• Korean Journal of Veterinary Service
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• v.42 no.3
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• pp.135-144
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• 2019

Low pathogenic avian influenza (LPAI; H9N2) and Newcastle disease (ND) are economically important poultry diseases in Korea. In this study, we investigated pathological features and virus distribution in the lymphoid tissues of chicks experimentally infected with H9N2 and/or ND virus. Six-weeks-old SPF chickens were divided into 4 groups, Control (C), H9N2 (E1), NDV (E2), and H9N2+NDV (E3). E1 group was challenged with 0.1 ml A/Kr/Ck/01310/01 (H9N2) $10^{5.6}$ $EID_{50}$ intranasally, E2 group was challenged with 0.5 ml KJW (NDV) $10^{5.0}{\sim}10^{6.0}$ $ELD_{50}$ intramuscularly, and E3 group was challenged with H9N2, followed 7 days later by NDV. In histopathological examination, E1 group showed depletion and necrosis in bursa of Fabricius, thymus, cecal tonsil, and spleen, whereas E2 and E3 groups were noted severe lymphocyte depletion and necrosis with destruction of lymphoid organs structures. In TUNEL assay, apoptotic bodies were detected in lymphoid organs of all experimental groups, which was most severe in E3 group. H9N2 and ND viruses were predominantly detected in cecal tonsil of E1, E2, and E3 groups by PCR and immunohistochemistry (ICH). In conclusion, co-infection of H9N2 with NDV caused severe pathologic lesions and apoptosis in lymphoid tissues compared to single infections.

• Korean Journal of Veterinary Service
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• v.24 no.4
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• pp.379-382
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• 2001

To confirm the effect of food and water deprivation prior to Newcastle disease(ND) virus vaccination, three hundred chicks were divided into five groups with three replications. ND vaccine were sprayed to at 1 -day old chicks at commercial hatchery. Secondary and third vaccination was conducted at 2-week old and 24-day old chicks by LaSota strain. Control was conventionally vaccinated without withdrawing the food and water before or after vaccination. In group 2(G2) and 3(G3), LaSota strain was vaccinated to chicks before and after fasting the food and water for 3 and 2 hours, respectively. Group 4(G4) has the same fasting time of group 2, but supplemented the skim milk in vaccin dilution water. In group 5(G5), skim milk was added into group 3. Weight gain, feed intake and feed conversion were weekly measured for 5 weeks. Blood was collected from wing vein at 24 and 35 days of age. Each serum antibody level were measured by hemagglutination inhibition(HI) test. The average weight gain, feed intake, feed conversion of all group were not significantly different. Weight gain of each groups was 1910.30(control), 1875.28(G2), 1952.12(G4) and 1896.05(G5), respectively. Feed intake of all group was recorded at 3160.67(control), 3167.07(G2), 3189.48(G3), 3157.85(G4) and 3178.16(G5), respectively. The feed conversion of each groups was 1.655(control), 1.688(G2), 1.633(G3), 1.699(G4) and 1.676(G5), respectively. The HI titer of G4 was $ 5.50{\Pm}$1.40 and significantly higher than the other groups (p<0.05)(control : $4.36{\Pm}$1.87 , G2 : $5.18{\Pm}$2.14, G3 : $4.51{\Pm}$2.19, G : $5.28{\Pm}$1.58 at 35 days old. The results of this experiment indicated that two or three hours of fasting time before or after vaccination would be able to show the higher antibody level against ND virus.

• Korean Journal of Veterinary Service
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• v.42 no.4
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• pp.245-250
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• 2019

Newcastle disease (ND) is an infectious poultry disease that caused high mortality and reduced egg production. NDVs are regularly present in the domestic duck population. And ducks play a possible role in the maintenance and transmission of NDVs. While we were monitoring the Avian Influenza, NDVs were isolated from field samples by accident. So we analysed the biological and genetic characteristics of these viruses. Lentogenic NDVs were isolated from two farms among twenty breeder duck farms. The ages of ducks were 39 weeks old in the 'A' farm and 3~72 weeks old in the 'B' farm. And they were not inoculated with the NDVs vaccine. In the biological characteristics, the both viruses which separated from the farm 'A' and 'B' were thermostable. The amino acid sequence of a site from 112 to 119 in the fusion (F) protein was 'GKQGRLIG' which has monobasic motif in the samples of both farms. And this means the separated NDVs are lentogenic. Phylogenetic analysis was performed by entire nucleotide sequence of F protein. The virus strains from the A farm (MN095239) and the B farm (MN095240) belonged to class II genotype I. Using the analysis of whole F protein nucleic acid sequence, the MN095239 (GenBank) had homology with Ulster strain about 99.95% and the MN095239 (GenBank) had homology with KR/CK/KU_LBM255/09 strain about 99.89%. NDV surveillance is needed to investigate epidemiological relationship of domestic breeder duck isolates in Korea.

• Korean Journal of Veterinary Service
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• v.13 no.1
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• pp.96-102
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• 1990

The immune responses of commercial layer chickens against Newcastle disease(ND) were compared among different administration methods and times of vaccination during 4 weeks of age. A total of 372 day-old chickens were divided into 4 groups of 93 birds each. Each of 3 groups was received a commercially available B$_1$live vaccine via drinking water, eye instillation or spray method at one, 14 and 28 days of age. One group was used as an unvaccinated control. At two and 4 weeks after each time of vaccination, 15 birds from each group were collected randomly out and challenged with virulent ND virus at the dose of $10^5E1D_{50}$ per bird. Ten to 15 birds from each group were bled at two weeks intervals from day old to 8 weeks of age for hemagglutination inhibition antibody titer, The protection rate was generally low regardless of the times of vaccination although two or more times vaccination gave higher protection than once vaccination. The low protection was considered due to low titer of the vaccine used since the vaccine titer was less than $10^{3.5}EID_{50}$ per bird. Spray method gave better protection compared to eye instillation or drinking water method which resulted in lowest response. Majority of birds showed clinical signs of ND between 3 and 6 days after challenge. Death occured one or two days after onset of symptoms. Major clinical signs observed were depression(94%), anorexia(84%), diarrhoea(29%), difficult breath(15%) and torticollis(10%). Hemorrhagic lesions on post mortem were seen in duodenum(51%), trachea(35%), illeum(13%), ceacal tonsil(11%), proventriculus(10%) and some other odrgans.

• Korean Journal of Poultry Science
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• v.39 no.1
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• pp.17-25
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• 2012

Coccidiosis control programs such as vaccines or in-feed anticoccidials are commonly practiced in the poultry industry to improve growth performance and health of commercial broiler chickens. In this study, we assessed the effects of various coccidiosis control programs (e.g., in ovo vaccination, synthetic chemicals, and antibiotic ionophores) on immune status of broiler chickens vaccinated against infectious bronchitis virus and Newcastle disease virus (ND) and raised on an Eimeria-contaminated used litter. In general, the levels of ${\alpha}$-1-acid glycoprotein, an acute phase protein, were altered by the treatments when measured at 34 days of age. Splenocyte subpopulations and serum antibody titers against ND were altered by various coccidiosis control programs. In-ovo-vaccinated chickens exhibited highest mitogenic response when their spleen cells were stimulated with concanavalin A (Con A) at 7 days of age. It is clear from this study that the type of coccidiosis control program influenced various aspects of innate and adaptive immune parameters of broiler chickens. Further studies will be necessary to delineate the underlying relationship between the type of coccidiosis control program and host immune system and to understand the role of other external environmental factors such as gut microbiota on host-pathogen interaction in various disease control programs.

• Korean Journal of Veterinary Service
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• v.40 no.2
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• pp.89-94
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• 2017

This study was conducted from May to December 2016 to investigate the prevalence of antibody titers for Newcastle disease (ND), Infectious Bronchitis (IB), Egg drop syndrome (EDS), Avian pneumovirus (APV), Fowl Typhoid (FT), Mycoplasma gallisepticum (MG), Mycoplasma synoviae (MS) in laying hens in Incheon area. In ND, 418 (99.5%) of the 420 outbreaks were positive. IB showed 330 (78.5%) positive antibody out of 420 cases. EDS showed 419 (99.7%) positive seropositive rates among 420 cases. In the case of APV, 357 cases (85%) were positive in 420 cases. In the case of PT, the positive rate of antibody was 128 (30.4%) out of 420 cases. Among the 420 cases of MG, 222 cases (52.8%) were positive for antibodies. In the case of MS, 395 out of 420 cases (94.0%) were positive. This result suggests that the positive rate of antibody for PT in Incheon area was low. And it was also clear that MS without vaccine is now rampant in Incheon.

• Korean Journal of Poultry Science
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• v.27 no.2
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• pp.109-114
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• 2000

The objective of these experiments was to develop an attenuated thermostable Newcastle disease virus(NDV), CBP-1 strain isolated from infected pheasants. Safety, pathogenicity and protective effects against velogenic NDV were also investigated to evaluate if the attenuated NDV, CBP-1 strain could be a candidate for a new NDV vaccine strain. CBP-1 strain was passaged up to the 173 times by nine days old embryonated eggs and chicken embryo fibroblast(CEF) cell cultures. Its sensitivitly to lipid solvents and low pH, thermostability, mean death time(MDT), intracerebral pathogenicity index(ICPI) of one day old chicks and intravenous pathogenicity index(IVPI) of four weeks old chicks were examined. Safety, boosting and protective effects were tested by chicks mortality. CBP-1 NDV strain had significant thermostability at 56$\^{C}$ for 30 minutes. by hemagglutinin activity and egg infectivity test, but was not resistant to lipid solvent. It showed possibility to use as a feed or water vaccine because of the resistance to low pH. MDT, ICPI and IVPI of CBP-1 were attenuated from 51.5, 1.96, 2.60 to 112.4, 1.12, 1.45. These results implied that the 173rd passages in embryonated egg and CEF cell cultures induced a substantial attenuation of the pathogenicity of the parent virus, changing the virulence from velogenic to intermediate between mesogenic and lentogenic. After vaccination with CBP-1 at one day old by drinking water mortality was 17.5%. However, spray vaccination with B1 at one day old, CBP-1 at two weeks ild and challenge with velogenic Kyojeongwon strain at four weeks old showed 93.5% survival rate. Mortality of chicks, vaccination with 173rd passaged CBP-1 strain at one day old, two weeks old and challenge with Kyokeongwon strain at four weeks old, was 20.0%. The results of these studies indicated that partial attenuated CBP-1 strain tended to be a low safety for ND of broiler chicks and would need to be more successive attenuation.

• Korean Journal of Poultry Science
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• v.8 no.2
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• pp.77-89
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• 1981

The experimental study was undertaken to confirm the effect of vaccination of birds with Newcastle disease (ND) vaccines on the Market by use of th. various vaccination programs. Sixteen groups of birds varying from 2 to f days of age, which were originated from hyper-immunised hens against ND were immunised by three different ways, a live vaccine only, a killed vaccine only, and the combination of a live and killed vaccine according to the each schedule of employed programs. In the administration of a live vaccine only, birds were immunized by one of following methods, the combination of intranasal and intraocular inoculation, intramuscular inoculation, via drinking water and the double inoculation by spray and drinking water application. Except for the double application, all the birds were vaccinated 2,3 or 4 times with two volumes of the virus dose (drinking water application) instructed by the commercial vaccine laboratory, until 21, 28 or 30 days of age, and all the immunized birds 19, 21 or 28 days postvaccination were challenged intramuscularly with 1.0$m\ell$ of 10,000 MLD per $m\ell$ of a virulent ND virus. In the administration of the combination of a live and killed vaccine, birds were immunized 2 or 3 times intranasally at first until 14 or 28 days of age with the same dose of the above experiment of a live vaccine, and then inoculated intramuscularly 1 or 2 times until 60 days of age with 1.0 $m\ell$ of a killed vaccine. And all immunized birds 11 days postvaccination were challenged with the same procedure of the above experiment. In the administration of a killed vaccine only, birds were immunized 3 times intramuscularly until 28 days of age with varied dose (0.2-0.5 $m\ell$) of a killed vaccine and all immunized birds 33 days postvaccination were challenged with the same procedure of the above experiment. The results obtained are summerised as follows: All birds vaccinated by using the combination of a live and killed vaccine program or a killed vaccin only appeared to be refractory. without any sign of illness, to the challenge exposure with 1.0$m\ell$ of 10,000 MLD per $m\ell$ of a virulent ND virus. On the other hand, the survival rates of birds of live vaccine groups immunized by a number of vaccine program such as Salsbury's day old program, 3-3-3 program, the Institute of Veterinary Reserch program and Multiple inoculation program, were 39.58%, 43.7%, 43.75% and 47.80%, respectively. And the survival rates of birds vaccinated with a live vaccine by 4 different ways of administration, i.e., double inoculation by water and aerosol application, intramuscular injection, intranasal instillation and via 4.inking water were 87.50%, 64.06%, 42.18% and 25.00%, respectively.