• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.163-169
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• 2013

Cryopreservation of poultry semen has been reported, but preservation of female genetic material has not been possible because of the unique anatomical and physiological characteristics of the avian egg. Thus an alternative strategy for conservation of oviparous species of animals must be developed. Recent technological developments for producing germline chimeras by the transfer of primordial germ cells (PGCs) into recipient embryos has enabled the conservation and retrieval of chicken genetic resources in their complete form. In the present study, fertilized eggs were incubated for about 5.5 days to obtain embryos at stage 28. The whole embryo was collected from the germinal gonad using a fine glass micro pipette under a microscope. The PGCs were then purified using MACS method. Two commercially available cryoprotectants (A and B) were used to preserve the PGCs, and EG were used as a control. The average recovery rate of PGCs after thawing was 35.5% and 60.5% with the A and B treatments, respectively. There was no significant difference between B treatments and control, which showed an average recovery rate of 52.8%. However, the recovery rate obtained using A cryoprotectant (35.5%) was significantly lower than using treatment control and B. The average viability of the PGCs after thawing were 77.9% and 77.4% for cryoprotectants A and B, respectively, and the control were was 81.6%. There was no statistically significant difference between the two treatments and control. It was concluded that all of the available cryoprotectants examined in this study could be used for preservation of PGCs from embryos. Further experiments to produce germline chimera from PGCs preserved using this techniques are strongly recommended.

• Korean Journal of Poultry Science
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• v.24 no.2
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• pp.85-90
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• 1997

An experiment was conducted to investigate the relationship between blood hormone levels and light cycle on performance of Korean native chicken. One hundred and two Korean native chickens were grouped into three treatments of natural light cycle (Control), 13L:11D (T2), and 16L:8D (T3). The egg production, egg weight, feed intake, serum melatonin and estrogen level were periodically measured from 22 to 34 weeks, respectively. The laying rates of T2 and T3 were significantly higher than that of the Control (P

• Proceedings of the Korea Society of Poultry Science Conference
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• 2001.11a
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• pp.77-79
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• 2001

This experiment was conducted to investigate the effects of Bamboo Vinegar Liquid(BVL) on performance and meat quality of Korean native chicken(KNC) for 8 weeks. One hundreds KNC were divided into 4 groups with 5 replicates per treatment and placed in pens. Dietary levels of food waste 0%, 1%, 2% and 4% were included in experimental diets. The growth performance and carcass weight of KNC fed BVL supplement diet were significantly different(P<0.05) from the control group. The lipid content, cholesterol content and TBA in breast meat were significantly(P<0.05) decreased by addition of BVL. However, the addition of BVL did not affect the meat color. The saturated fatty acid composition of breast meat was decreased(P<0.05), whereas unsaturated fatty acid was increased(P<0.05) by addition of BVL 1% and 2%. Taste of sensory evaluation was improved by addition BVL. The results of this study indicate that dietary supplemental BVL 1% and 2% may improve the performance and meat quality of KNC. The prevention effect of KNC which challenged with Salmonella gallinarum (1${\times}$10$\^$9/ CFU/ml) was evaluated. A reisolation of S.gallinarum in liver, pathological index of villus and colon were evaluated. There was no reisolation of S.gallinarum in liver and a few pathological index of colon in 4% BVL supplement fed KNC than 1 and 2%. These results indicate that dietary supplemental BVL 4% may improve the prevention effect to salmonellosis in chickens.

• Korean Journal of Poultry Science
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• v.26 no.4
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• pp.261-265
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• 1999

The objective of this experiment was to investigate the effect of feeding Angelica gigas Nakai by-products on performance and meat quality of Korean native chicks(KNC). Five hundred forty KNC were placed into 0, 0.2, and 0.4% Angelica gigas supplements with four replications between males and females. Weight gain, feed conversion ratio(FCR), breast meat lipid, fatty acid and protein contents were measured from 17 to 20 weeks old. Egg production, feed intake and FCR were examined from 22 to 29 weeks at four weeks at four weeks intervals. Basal diets based on corn and soybean meal contained 15% crude protein and 2,850㎉/kg ME for the growing period, 16.5% and 2,800㎉/kg for the laying period. Experiments were designed in a one way analysis. Weight gain of female chicks fed 0.2% Angelica gigas by-products increased significantly compared to that of other treatments for the growing period, but was not consistency in male groups. Moisture, protein, fat content were not statistically different among all treatments. Fatty acid composition(C16:0, C18:0) of chicks fed 0.2% Angelica gigas by-products was higher than other treatments. In laying period, hens fed 0.2 or 0.4% Angelica gigas Nakai by-products seemed to increase the egg production and significantly improved FCR compared to that of control(P〈0.05). Birds fed 0.4% treatment showed significantly the lowest feed intake and FCR of all treatments(P〈0.05). The results of these studies indicated that dietary supplemental Angelica gigas by-products may have a role to improve the performance of KNC.

• Korean Journal of Poultry Science
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• v.30 no.2
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• pp.129-134
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• 2003

This study was conducted to investigate the effects of liquid rooster semen on reproductive ability in chicken. Raw and diluted semens were stored at 5$^{\circ}C$ cold temperature for 6, 30, and 54 hours after semen collection. There was no statistically difference in sperm motility throughout the 6 hours period of storage among raw semen and diluted semen groups with skim milk glucose solution (SM), egg yolk glucose solution (EY), and saline. But there was decrease in those throughout the period of 30 and 54 hours of storage. Sperm motility and normal sperm for the period of 30 and 54 hours of storage were significantly better in SM and EY diluted groups (P<0.05). Fertilization rates of rooster semen diluted with SM were 90.77, 87.70, and 59.46% for 6, 30, and 54 hours stored groups, respectively, those proved to be higher in SM-diluted group than other groups.

• Korean Journal of Poultry Science
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• v.33 no.2
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• pp.97-103
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• 2006

Telomeres are essential for chromosome stability and are related with cell senescence, apoptosis and cancer. Even though telomere length and telomerase activity have been studied extensively, very little is known to analyze the telomere dynamics in chicken cells. This study was carried out to analyze the telomere distribution and telomerase activity of Korean Native Chicken cells along with aging. The cells were collected from brain, heart, liver, kidney and germinal tissues during physiological stages. Telomere distribution was analyzed by Quantitative-Fluorescence in situ Hybridization (Q-FISH) techniques using the chicken telomeric DNA probe. Telomerase activity was performed by Telomeric Repeat Amplification Protocol (TRAP) assay. In results, the telomeres of chicken were found at the ends of all chromosomes with the interstitial telomeres on chromosomes 1, 2 and 3. The amount of telomeres on chicken cells was decreased along with aging in most tissues. Furthermore, the telomere quantity was significantly different among tissues. The relative amount of telomeres in proliferous cells such as testis cells had much more than those of liver, brain, heart, blood and kidney cells. The telomerase activity was down-regulated in cells of brain, heart and liver tissues. Whereas gonadal cells showed a constitutive activity of telomerase during all stage of life. In conclusions, the telomere quantity and telomerase activity in chicken are closely relate to cell proliferation and tissue specificity during developmental stages and aging. There is also closely correlated between the amounts of telomeric DNA and telomerase activity in chicken tissues.

• Korean Journal of Poultry Science
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• v.34 no.2
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• pp.151-156
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• 2007

The Function of the calcium sensing receptor (CaSR) is to control calcium levels by altering PTH (parathyroid hormone) secretion and renal calcium resorption. The influence of calcium on the basal and stimulated release of several hormones from chicken pituitary glands has been determined in vitro. The objective of this study was to identify SNP in chicken CaSR gene and to investigate the effect of the SNP on economic traits. The sequencing analysis method was used to identify nucleotide polymorphisms within chicken CaSR gene. This study identified SNP at position 1949 bp(Genebank accession No : XM_416491) in the exon 1. The SNP changed the amino acid to alanine(GCC) from serine(TCC). This SNP showed three genotypes, AA, AS and SS by digestion with the restriction enzyme NcoⅠ using the PCR-RFLP method. The A963S showed significant effect only on the first lay day (P<0.05) in Leghorn population. Leghorn with the genotype AA had significantly faster the first lay day(137.6) than the genotype AS(143.0, P<0.05). Also, the A963S showed significant effect only on the first lay day(P<0.05) and mean of egg weight(P<0.05) in KNC population. KNC with the genotypes AA ans AS had significantly faster the first lay day (151.0 and 152.6, respectively) than the genotype SS(159.4, P<0.05). And the genotypes SS had significantly heavier the mean of egg weight(50.4 kg, P<0.05) than the genotype AA ans AS (47.5 and 47.8 kg, respectively). According to result of this study, an a allele of the A963S was found to have a significant effect on the first lay day. It will be possible to use this SNP marker on selecting chicken to improve the first lay day.

• Korean Journal of Veterinary Research
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• v.38 no.1
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• pp.91-99
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• 1998

The immunogenetic analysis was performed to characterize the Korean native chickens (KNC) determined by monoclonal antibodies specific to chicken leukocyte differentiation antigens and flow cytometry. A total of 174 chickens including 58 KNC (black, brown and darkbrown colored), 77 foreign breed (Nagoya, White Reghorn, Rhode Island and Cornish) and 39 mixed breed (19 KNC with Nagoya and 20 KNC with Rhode Island) separately growing at Animal Science and Technology Institute were examined. The proportion of cells expressing MHC class II molecule (B-L in chicken) was significantly high in KNC. Proportion of CD4+ T helper cells was also higher in KNC and two mixed breed than that in foreign breed. However, proportion of CD8+ cells and TCR1 + (${\gamma}^{\delta}$ T cell receptor) cells was the lowest among the breed examined. Otherwise, those proportions were significantly high in White leghorn and two mixed breeds with two exclusive subpopulations. The two subpopulations were also typically shown in MHC class $II^+$ cells in KNC and one mixed breed, black-colored KNC with Nagoya. Although genotypic analysis was not pursued to characterize the immunogenetic properties of KNC, difference of phenotypic expression based on leukocyte differentiation molecules could be elucidated in KNC in this study.

• Journal of Animal Science and Technology
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• v.54 no.2
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• pp.125-131
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• 2012

The study was conducted to investigate the effects of dietary supplementation of Macsumsuk and herb resources on the egg performance and quality in Korean native crossbred chickens. A total of three hundred sixty improved Korean native crossbred chickens in primary laying period were randomly allocated to four treatments (30 birds/treatment ${\times}$ 3 replications) for eight weeks. Dietary treatments included CON (basal diets), T1 (basal diets + 0.3% Macsumsuk), T2 (basal diets + 0.3% herb resources) and T3 (basal diets + 0.3% Macsumsuk + 0.3% herb resources). No significant differences were found for feed intake, egg weight and average egg production (P>0.05), however, cracked egg rate was higher in CON than in T1-T3, especially T3 was the lowest (P<0.05). The crude fat content of whole eggs, CON (11.20%) was higher (P<0.05) than the experimental treatments (9.67%-10.01%). Haugh unit, yolk color, eggshell thickness, and eggshell breaking strength tended to be higher in T1 and T2, but there were no significant differences (P>0.05). However, the experimental treatments were significantly higher than CON (P<0.05) for eggshell breaking strength, and T3 (14.91 mg/g) contained lower (P<0.05) cholesterol in egg yolk than other treatments. For fatty acid composition in egg yolk, CON group showed higher saturated fatty acid contents than the experimental treatments, but T1 (67.00%), T2 (66.78%) and T3 (66.82%) were higher than CON for unsaturated fatty acids (P<0.05). In conclusion, supplementating Macsumsuk and herb resources together in diets of Korean native crossbred chickens could decrease egg yolk cholesterol and improve egg quality.

• Korean Journal of Poultry Science
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• v.48 no.1
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• pp.41-50
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• 2021

Although feather-sexing using sex-linked genes related to feather development is a widely used chick sexing method in the poultry industry, the feather-sexing method has yet to be used for Korean native chickens (KNCs). The purpose of this study was to construct a KNC feather-sexing line using early-feathering (EF) and late-feathering (LF) genes for industrial application. Using 557 reddish-brown KNCs as the basal flock, frequencies of the EF (k) and LF (K) genes were estimated to be 0.814 and 0.186, respectively. This indicating that it would be feasible to construct a feather-sexing line using this chicken group, and we accordingly constructed EF paternal and LF maternal lines. On the basis of test-cross for the selection of LF homozygous (KK) males in the maternal line, we confirmed that three of 40 chickens were homozygous males. The survival rate, body weight, days at first egg-laying, hen-day egg production, and egg weight were analyzed to compare the production performance of EF and LF chickens. The results revealed that EF chickens were characterized by a superior survival rate, whereas LF chickens were superior in terms of egg production rate. However, no differences between LF and EF chickens were detected with respect to other production performance parameters. In addition, assessment of the fitness of sexed chicks produced in the established KNC feather-sexing lines revealed that the accuracy of sexing was 98.6%. Collectively, these findings indicate the feasibility of constructing effective KNC feather-sexing lines with potential industrial application.