• Korean Journal of Poultry Science
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• v.43 no.3
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• pp.135-142
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• 2016

This study was conducted to compare the general composition and immunomodulatory activity of breast and thigh meats from four lines of Korean native chickens: Yeonsan Ogye, Hyunin Black, Hwangbong, and Hoengseong Yakdak. White Leghorn was used as a control. Fifteen male chickens (three chickens in each line) were grown under the same conditions and slaughtered at 13 weeks old. The four lines of Korean native chickens, regardless of the part, had higher contents of crude fat (p<0.05) than White Leghorn. The cholesterol contents were significantly higher in Hyunin Black and significantly lower in Hoengseong Yakdak than those of other chickens (p<0.05). The immunomodulatory effect, assessed by macrophage cell proliferation and nitric oxide production, was only observed in the breast meat of the four lines of Korean native chickens. The phagocytic activity of macrophage cells was significantly augmented by the breast meat of Hyunin Black and Hoengseong Yakdak. Furthermore, the mRNA expressions of pro-inflammatory cytokines, such as IL-4, IL-10 and $IFN-{\gamma}$, was significantly suppressed by Korean native chickens compared with White Leghorn. These results suggested that the four lines of Korean native chickens exhibited greater immune-enhancing activity than White Leghorn.

• Korean Journal of Poultry Science
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• v.44 no.1
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• pp.1-9
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• 2017

The objective of the present study was to determine the expression of genes associated with lipopolysaccharide (LPS)-induced stressor in two breeds of chickens: the Korean native chicken (KNC) and the White Leghorn chicken (WLH). Forty chickens per breed, aged 40 weeks, were randomly allotted to the control (CON, administered the saline vehicle) and LPS-injected stress groups. Samples were collected at 0 and 48 h post-LPS injection, and total RNA was extracted from the chicken livers for RNA microarray and quantitative real-time polymerase chain reaction (qRT-PCR) analyses. In response to LPS, 1,044 and 1,193 genes were upregulated, and 1,000 and 1,072 genes were downregulated in the KNC and WLH, respectively, using a ${\geq}2$-fold cutoff change. A functional network analysis revealed that stress-related genes were downregulated in both KNC and WLH after LPS infection. The results obtained from the qRT-PCR analysis of mRNA expression of heat shock 90 (HSP90), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), activating transcription factor 4 (ATF4), sterol regulatory element-binding protein 1 (SREBP1), and X-box binding protein 1 (XBP1) were confirmed by the results of the microarray analysis. There was a significant difference in the expression of stress-associated genes between the control and LPS-injected KNC and WLH groups. The qRT-PCR analysis revealed that the stress-related $HSP90{\alpha}$ and HMGCR genes were downregulated in both LPS-injected KNC and WLH groups. However, the HSP70 and $HSP90{\beta}$ genes were upregulated only in the LPS-injected KNC group. The results suggest that the mRNA expression of stress-related genes is differentially affected by LPS stimulation, and some of the responses varied with the chicken breed. A better understanding of the LPS-induced infective stressors in chicken using the qRT-PCR and RNA microarray analyses may contribute to improving animal welfare and husbandry practices.

• Korean Journal of Poultry Science
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• v.35 no.4
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• pp.361-366
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• 2009

The purpose of this study was to assess the genetic variation and establish the relationship amongst breeds and strains using 7 chicken specific microsatellite markers. A total of 317 DNA samples from four Korean native chicken (KNC) strains (KR: Korean Native Red chicken strain, KY: Korean Native Yellow chicken strain, KL: Korean Native Black chicken strain, KO: Ogol chicken strain) and three introduced endemic chicken breeds (LE: Leghorn chicken breed, RI: Rhode Island Red chicken breed, CO: Cornish chicken breed). The size of microsatellite markers was decided using GeneMapper Software (v.4.0) after being analyzed using an ABI 3130 Genetic Analyzer. Frequencies of microsatellites markers were used to estimate heterozygosities and genetic distances. The lowest distance (0.074) was observed between the KY and KL breeds and the highest distance (0.779) between the KL and LE breeds. The KNC strains (KR, KY, KL) have comparatively near genetic distance each other. On the other side, each individual was not ramified to different groups and were spread evenly in phylogenetic dendrogram about all the KNC of each strain populations. But the endemic breed populations (LE, RI, CO) were ramified to different groups. The microsatellite polymorphism data were shown to be useful for assessing the genetic relationship between Korean native strains and other foreign breeds.

• Korean Journal of Poultry Science
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• v.42 no.4
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• pp.335-345
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• 2015

This study was conducted to compare carcass yield and meat quality among four lines of Korean native chickens (Yeonsan Ogye, Hyunin Black, Hoengseong Yakdak and Hwangbong) and White Leghorn as control. Chickens (N=23, male) were grown under same conditions and slaughtered at 56 weeks old to observe the physicochemical differences in breast and leg meats. The live and carcass weights of Hwangbong were significantly higher than other chickens (p<0.05). Four lines of Korean native chickens, regardless of the part, had higher shear force value than White Leghorn (p<0.05). In addition, the breast meat of Korean native chickens had higher cooking loss and lower water holding capacity than that of White Leghorn. The cooked meat of Hwangbong particularly were more chewy, gummy and cohesive with lower tenderness than other chickens (p<0.05). Oleic acid content which is related to meat flavor was significantly higher in the breast meat of Hoengseong Yakdak (39.6%). The meat of Korean native chickens had lower n6/n3 ratio, in which the breast and leg meat of Hoengseong Yakdak contained the lowest ratio (p<0.05). The meat of Hwangbong and Hoengseong Yakdak were more acceptable than the others according to sensory test (p<0.05).

• Korean Journal of Poultry Science
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• v.47 no.3
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• pp.189-197
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• 2020

This study was conducted to compare the production performance and stress response of chickens kept in the conventional cages and floor pens. 491 female White Leghorns were used in this study, and their production characteristics and stress response indicators were analyzed from 34 to 43 weeks of age. The results showed that there was no significant difference in survival rate, hen-day egg production, and body weight between the chickens kept in the conventional cages and those kept in the floor pens. The chickens kept in the conventional cages had a significantly higher egg weight and egg quality compared with those kept in the floor pens (P<0.01). The amount of telomeric DNA in lymphocytes was significantly higher in the chickens kept in floor pens than in those kept in conventional cages (P<0.05). The heterophil-lymphocyte ratio, HSP-90β gene expression level, and DNA damage rate significantly increased in chickens kept in the conventional cages, as compared to the chickens kept in floor pens (P<0.01). In conclusion, there seems to be no difference in the production performance between chickens kept in conventional cages and those kept in floor pens. Furthermore, chickens kept in conventional cages had higher stress response values than those kept in floor pens for all stress response indicators. Therefore, conventional cage types are considered to be a more stressful environment for chickens than floor pens, regardless of the production performance of the chickens.

• Korean Journal of Poultry Science
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• v.36 no.4
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• pp.293-300
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• 2009

The rate of fetus with abnormal chromosomes increase with maternal age. Nondisjunction of aging oocyte chromosome is a major reason for the increased rate of abnormalities. Telomeres are the ends of eukaryotic chromosome, which are essential for chromosome stability and are related in cell senescence. This study was carried out to analyze the chromosome aberration rate and amount of telomeric DNA in chick embryo along with maternal age. Fertilized eggs and blood were sampled from White Leghorn layers starting at 20 weeks through to 70 weeks age at 10 weeks interval. Chromosome aberration rate was analyzed by karyotyping. The amounts of telomeric DNA in embryonic cells and lymphocytes were quantified by Quantitative Fluorescence in situ Hybridization method. The chromosome aberration rate in chick embryos significantly differed with maternal age. The chromosome aberration rate increased at early laying period and beyond 70 weeks of maternal age. Therefore, chromosome aberration rate was affected by maternal age due to ovulated oocytes state. However, the amount of telomeric DNA on embryonic cells did not differ significantly with maternal age. Thus, maternal age does not affects telomere quantity in their embryos due to cellular reprograming at early embryonic stage after fertilization.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.815-823
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• 2014

Green tea has been known to show beneficial effects on alleviating stress. The present study was conducted to determine the effects of dietary green tea on quality of eggs, during storage, laid by laying hens treated with corticosterone in order to mimic the current practice of the egg market. Hens were fed for 2 weeks one of three diets containing green tea at 0.0, 0.4 or 1.0%. Each dietary group was divided into two subgroups receiving corticosterone at 0 or 30 mg/kg for 1 week. Eggs, laid at 5-7 days following the initiation of corticosterone treatment, were stored at $10^{\circ}C$ for 1 or 5 weeks and then analyzed for egg quality. After 1 week of storage, egg weight was significantly increased by green tea (p<0.025) but decreased by corticosterone (p<0.0001), but no interaction was observed between both. Corticosterone decreased shell color (p<0.0001) but green tea significantly decreased shell strength (p<0.006). Yolk color, albumen height and Haugh unit were not affected by both treatments. After 5 weeks of storage, corticosterone resulted in reduced egg weight (p<0.01) and eggshell color (p<0.001) and increased shell strength, which were not attenuated by green tea. Taken together, the results of the current study show that dietary corticosterone reduces egg quality during storage, which are attenuated in part by dietary green tea.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.207-216
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• 2013

This study was conducted to establish the method for preserving PGCs that enables long-term storage in liquid nitrogen for developmental engineering or preservation of species. The purpose of this study is to clarify the effects of freeze-thaw treatment on viability of PGCs in chickens. PGCs were collected separately from a germinal gonad of an early embryo of 5.5~6 day (stage 28) of Isa brown, Korean Oge (KO), White Leghorn and Commercial breeds. PGCs separated from a germinal gonad of an early embryo of 5.5~6 day (stage 28) are suspended in a freezing medium containing a freezing and protecting agents (e.g. dimethyl sulfoxide (DMSO), ethylene glycol (EG) and glycerol). The PGCs were then purified using magnetic activated cell sorting (MACS) method. The viability of PGCs after thawing was $87.4{\pm}0.4%$ and $89.4{\pm}0.2%$ with the 10% EG treatments with no significant difference between the Isa brown and Commercial breeds. The viability of PGCs after freeze- thawing was significantly higher for Isa brown ($87.4{\pm}0.4%$) and Commercial breeds ($89.4{\pm}0.2%$) than Korean Oge (KO) ($77.6{\pm}1.1%$) and White Leghorn ($76.2{\pm}0.9%$)(p<0.05) using 10% EG cryoprotectant. This study established a method for pre- serving chicken PGCs that enables systematic storage and labeling of cryopreserved PGCs in liquid ($LN_2$) at agermplasm repository and ease of entry into a data base. In the future, the importance for this new technology is that poultry lines can be conserved while work is being conducted on improving the production of germline chimeras.

• Korean Journal of Poultry Science
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• v.41 no.2
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• pp.87-92
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• 2014

The avian embryos have been used as a good model to study embryonic development. Due to its unique development in the eggshell, avian embryos can be cultured and hatch in the surrogate eggshell system. In this study, we examined the viability, normal development and hatchability of Korean Oge (KO) chicken embryos in White Leghorn (WL) surrogate eggshells. Donor KO embryos at 3-day and 4-day-old were transferred into recipient WL eggshells, incubated for further 18 days at $37.5^{\circ}C$ with 70% of humidity until hatching. The viability of 3-day-old KO embryos at 7, 14 and 21 day in surrogate eggshell were 70.0%, 43.8% and 23.1%, respectively. In contrast, the viability of 4-day-old KO embryos at 7, 14 and 21 day in surrogate eggshells were 87.1%, 55.6% and 36.0%, respectively. The hatchability of KO embryos transferred into surrogate eggshells at 3-day-old was 23.1%, whereas embryos transferred at 4-day-old was 36.0%. Furthermore, the development of all viable embryos from 3-day group and 4-day group were normal. Our results suggested that culture of KO embryos in WL surrogate eggshells is highly possible, and transfer of donor embryos at 4-day-old may yield higher percentage of hatchability. This study may provide potential knowledge for the conservation of wild and endangered birds through surrogate system.

• Korean Journal of Poultry Science
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• v.42 no.1
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• pp.15-26
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• 2015

In this study, genotyping was executed by using 27 microsatellite markers for genetic diversity of 469 Korean Native Chickens [20 population, each population is 24 samples but Hanhyup A line is 13 samples). in total 469 samples were collected from National Institute of Animal Science (Korean Native Chicken (NR, NY, NG, NL and NW), Ogye (NO), Leghorn F,K (NF and NK), Black and Brown cormish (NH and NS), Rhode Island Red C, D (NC and ND), Total is 12 populations] and Hanhyup [H line (HH), F line (HF), G line (HG), V line (HV), S line (HS), W line (HW), Y line (HY), A line (HA), total is 8 populations]. [The allele number were observed 5 (ADL0268) to 20 (MCW0127) each markers. Observed heterozygostiy ($H_{obs}$), expected heterozygosity ($H_{exp}$), polymorphism Information Content (PIC) were observed 0.359 to 0.677, 0.668 to 0.881 and 0.646 to 0.869, respectively. Using these markers, the calculated the heterozygote deficit within chicken line ($F_{is}$) value each population from mean 0.117. Phylogenetic tree showing the genetic relationship among 20 population using standard genetic distance calculated from 27 microsatellite markers. genetic distances revealed the closest (0.175) between NC and ND. on the other hand, Farthest genetic distances (0.710) revealed between NF and HV. STRUCTURE analysis and Principal Components Analysis (PCA) showed that results of similar phylogenetic tree. The expected probability of identity values on random individuals (Total population and only Hanhyup line) was estimated at $8.80{\times}10^{-83}$ and $3.87{\times}10^{-117}$, respectively. In conclusion, This study shows the useful data that be utilized as a basic data of Korean Native Chicken breeding and development for commercial chicken industry to meet the consumer's demand.