• KOREAN POULTRY JOURNAL
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• v.53 no.12
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• pp.164-166
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• 2021

• Korean Journal of Veterinary Service
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• v.42 no.3
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• pp.161-167
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• 2019

The poultry red mite (PRM), Dermanyssus gallinae, causes great economic losses to poultry industries in Korea. The molecular epidemiological characterization of PRM has been investigated in some countries, but those analysis has been not conducted yet in Korea. The aim of this study is to determine the genetic diversity of PRMs in Korea compared with those from other countries. Here, 13 PRM samples collected from Korea were analyzed with a part of the mitochondrial cytochrome oxidase subunit I (COI) gene and nuclear internal transcribed spacers (ITS) region. All the samples showed an identical COI sequence, which has also been reported in European countries and Japan. Phylogenetic diversity analysis showed that the mites from Korea were genetically related to those in other countries. The nuclear ITS region sequences were classified into three sequence types. Additionally, one of the ITS sequences was an intermediate type, implying that a hybridization event occurred among the mite populations in Korea. These findings suggested PRMs from Korea showed low genetic diversity with respect to mitochondrial COI gene, but three different populations inhabited in Korea with respect to nuclear ITS region sequences.

• Korean Journal of Poultry Science
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• v.19 no.2
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• pp.65-76
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• 1992

Since the first outbreaks of Newcastle disease ( ND) in Korea was reported in 1927, the disease has been a major problem in Korean poultry industry. Several attempts related ND prevention and controls have been tried and significantly reduced the ND outbreaks. However, recently frequencies of ND outbreaks have been increased throughout the country since 1988. Many assumptions such as variances of ND virus pathogenicity, decreased efficacy of ND vaccine, incorrect vaccination program etc, has been issued and discussed. Therefore, to clearly understand this recent situation of ND outbreaks in Korea, we reviewed all available past informations related with ND outbreaks in Korea and compared the virulence of recently isolated ND viruses with that of a reference one. Also, we discussed about some problems related with serological diagnosis. administration methods of vaccine and vaccination program.

• Korean Journal of Poultry Science
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• v.43 no.4
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• pp.243-251
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• 2016

Chicken not only serves as a high-protein source to humans, but it is also used as a suitable biomodel for increasing livestock productivity and studying human diseases. Chickens have numerous advantages as model organisms mainly because of they are relatively convenient to manage due to their small body size and short generational interval. In addition, they have a small genome size and numerous genes have biologically similar functions to those of human and livestock animals. In this review, we investigated the chicken biomodel for human disease research and the use of this model for increasing livestock productivity. This summary could provide useful and basic information for further development of strategies for enhancing livestock production and human disease studies.

• Journal of Veterinary Science
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• v.23 no.2
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• pp.21.1-21.7
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• 2022

Newcastle disease (ND), infectious laryngotracheitis (ILT) and avian metapneumovirus (aMPV) can be similar making it critical to quickly differentiate them. Herein, we adapted pre-existing molecular-based diagnostic assays for NDV and ILTV, and developed new assays for aMPV A and B, for use under synchronized thermocycling conditions. All assays performed equivalently with linearity over a 5 log₁₀ dynamic range, a reproducible (R² > 0.99) limit of detection of ≥ 10 target copies, and amplification efficiencies between 86.8%-98.2%. Using biological specimens for NDV and ILTV showed 100% specificity. Identical amplification conditions will simplify procedures for detection in diagnostic laboratories.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.9
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• pp.1247-1253
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• 2003

Selection for increased milk production in dairy cows has often resulted in a higher incidence of disease and thus incurred a greater health costs. Considerable interests have been shown in breeding dairy cattle for disease resistance in recent years. This paper discusses the limitations of breeding dairy cattle for genetic resistance in six parts: 1) complexity of disease resistance, 2) difficulty in estimating genetic parameters for planning breeding programs against disease, 3) undesirable relationship between production traits and disease, 4) disease as affected by recessive genes, 5) new mutation of the pathogens, and 6) variable environmental factors. The hidden problems of estimating genetic and phenotypic parameters involving disease incidence were examined in terms of categorical nature, non-independence, heterogeneity of error variance, non-randomness, and automatic relationship between disease and production traits. In light of these limitations, the prospect for increasing genetic resistance by conventional breeding methods would not be so bright as we like. Since the phenomenon of disease is the result of a joint interaction among host genotype, pathogen genotype and environment, it becomes essential to adopt an integrated approach of increasing genetic resistance of the host animals, manipulating the pathogen genotypes, developing effective vaccines and drugs, and improving the environmental conditions. The advances in DNA-based technology show considerable promise in directly manipulating host and pathogen genomes for genetic resistance and producing vaccines and drugs for prevention and medication to promote the wellbeing of the animals.

• Korean Journal of Poultry Science
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• v.26 no.3
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• pp.149-170
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• 1999

Protozoa of the genus Eimeria are the etiologic agents of avian coccidiosis, the most economically important Parasitic disease for the poultry industry. Coccidia multiply in intestinal epithelial cells of a wide range of hosts, including livestock in addition to poultry. Chemotherapy is extensively used to control coccidiosis. However, development of drug resistance by Eimeria parasites, the intensive cost and labor involved in the identification of new anticoccidial compounds and public awareness of drug residues in foods warrant alternative methods to prevent coccidiocic in the fast growing poultry industry. For these reasons, there is a great interest in developing vaccines against avian coccidiosis. Live Eimeria vaccines confer protective immunity, however a significant disadvantage of using these types of vaccines is their pathogenicity. Live parasites with attenuated pathogenicity also usually produce immunity but may revert back to a pathogenic form and may be contaminated with other pathogenic organisms. Killed Eimeria vaccines are safer but, unlike live attenuated vaccines, are not able to generate cytotoxic T lymphocyte responses. Recombinant vaccines are biochemically purified proteins produced by genetic engineering that consist of particular epitopes or metabolites of Eimeria. Unlike live attenuated organisms, recombinant vaccines do not possess as much risk and generally are able to induce both humoral and cell mediated immunity. DNA vaccines consist of genes encoding immunogenic proteins of pathogens that are directly administered into the host in a manner that the gene is expressed and the resulting protein generates a protective immune response. Although all of these different types of vaccines have been applied to coccidiosis, this disease continues to cause substantial morbidity and mortality in the poultry industry. Future development of an effective vaccine against coccidiosis will depend on further investigation of protective immunity to Eimeria infection and identification of important immundgenic parasite molecules.

• Korean Journal of Poultry Science
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• v.46 no.4
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• pp.249-253
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• 2019

Various factors negatively affect poultry production, including a multitude of avian pathogens. Among them, Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) cause world-wide economic losses in the poultry industry. Although respectively, MG and MS induce chronic respiratory disease and synovitis in poultry, these pathogens often manifest as clinically inapparent infections and many countries are therefore having difficulties effectively eradicating them. In this study, five broiler breeder farms in Korea were investigated for the presence of Mycoplasma infection from 2016 to 2018. Serum samples were collected for detection of antibodies to mycoplasma species using an enzyme-linked immunosorbent assay (ELISA) kit. Additionally, the production index and feed conversion rate of broilers were recorded. According to this investigation, broiler breeder farms in 2018 were serologically negative for Mycoplasma infection with broilers exhibiting a high production index and low feed conversion rate. Thus, eradicating mycoplasma in poultry farms is critical for improving chick quality and overall poultry production.

• Journal of Animal Science and Technology
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• v.65 no.2
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• pp.441-458
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• 2023

The poultry industry, which produces excellent sources of protein, suffers enormous economic damage from diseases. To solve this problem, research is being conducted on the early detection of infection according to the behavioral characteristics of poultry. The purpose of this study was to evaluate the potential of a non-movement behavior observation method to detect sick chickens. Forty 1-day-old Ross 308 males were used in the experiments, and an isolator equipped with an Internet Protocol (IP) camera was fabricated for observation. The chickens were inoculated with Salmonella enterica serovar Gallinarum A18-GCVP-014, the causative agent of fowl typhoid (FT), at 14 days of age, which is a vulnerable period for FT infection. The chickens were continuously observed with an IP camera for 2 weeks after inoculation, chickens that did not move for more than 30 minutes were detected and marked according to the algorithm. FT infection was confirmed based on clinical symptoms, analysis of cardiac, spleen and liver lesion scores, pathogen re-isolation, and serological analysis. As a result, clinical symptoms were first observed four days after inoculation, and dead chickens were observed on day six. Eleven days after inoculation, the number of clinical symptoms gradually decreased, indicating a state of recovery. For lesion scores, dead chickens scored 3.57 and live chickens scored 2.38. Pathogens were re-isolated in 37 out of 40 chickens, and hemagglutination test was positive in seven out of 26 chickens. The IP camera applied with the algorithm detected about 83% of the chickens that died in advance through non-movement behavior observation. Therefore, observation of non-movement behavior is one of the ways to detect infected chickens in advance, and it appears to have potential for the development of remote broiler management system.

• Korean Journal of Poultry Science
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• v.6 no.2
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• pp.109-109
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• 1979

The poultryman and feed formulator must decide on proper management in a complex environment of continuous flux in diseases, nutrition and genetics of the bird. (omitted)