• Asian-Australasian Journal of Animal Sciences
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• v.19 no.11
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• pp.1546-1550
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• 2006

The purpose of this study was to assess the genetic variation and establish the relationship amongst breeds and strains using 15 chicken specific microsatellite markers. A total of 285 unrelated DNA samples from four Korean native chicken strains (Black strain of Korean native chicken; KL, Red Brown strain of Korean native chicken; KR, Ogol strain of Korean native chicken; KS and Yellow Brown strain of Korean native chicken; KY) and three introduced chicken breeds (F strain of White Leghorn; LF, K strain of White Leghorn; LK, Rhode Island Red; RC and Cornish; CN) were genotyped to estimate within and between breed genetic diversity indices. All the loci analyzed in 15 microsatellite markers showed a polymorphic pattern and the number of alleles ranged from 5 to 14. The polymorphism information content (PIC) of UMA1019 was the highest (0.872) and that of ADL0234 was the lowest (0.562). The expected total heterozygosity (He) within breed and mean number of observed alleles ranged from 0.540 (LF) to 0.689 (KY), and from 3.47 (LK) to 6.07 (KR), respectively. The genetic variation of KR and KY were the highest and the lowest within Korean native strains, respectively. The genetic distance results showed that Korean native chicken strains were separated with the three introduced chicken breeds clustered into another group. The lowest distance (0.149) was observed between the KR and KL breeds and the highest distance (0.855) between the KR and LK breeds. 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.45 no.3
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• pp.175-182
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• 2018

The carcass and meat quality of new native chicken strains (A, C, and D) being developed in the Golden Seed Project for Samgyetang were compared with a commercial native chicken (Hanhyup No. 3, H) and Baeksemi (white semi broiler, W) strains. In total, 250 male chicks were raised under the same feeding and raising conditions for 5 weeks. After slaughter, the carcass weight and percentage yield of parts from each strain were measured and the physicochemical quality traits (general composition, color values, fatty acid composition, and sensory evaluation) of breast muscles were comparatively analyzed. The carcass weight (875.10 g) of the W strain was significantly heavier than that of the other native chicken strains, while that of A strain (537.54 g) was the lowest. The percentage yield of breast meat was also higher in the W strain than in the other strains. The fat content of W strain was higher than that of the other native chicken strains. The new native chicken strains (A, C, D) had higher contents of linoleic acid (C18:2) than the H strain. The A and D strains especially showed relatively high content of arachidonic acid (C20:4), a characteristic fatty acid in native chicken meats. On the other hand, the fatty acid composition of C strain was similar to that of the W strain. This study provides important information on specific quality characteristics than can be used to select new native chicken lines for breeding program.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.12
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• pp.1653-1658
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• 2000

Insulin-like growth factor-I (IGF-I) mRNA levels in the eyes, heart, liver and breast muscle removed from dwarf egg-type, normal egg-type and normal meat-type chicken embryos at 7, 14 and 20 days of incubation were measured. There was no influence of chicken strain on IGF-I gene expression in the eyes and liver. The IGF-I gene expression in eyes increased significantly along with the incubation period. In the liver, IGF-I gene expression at 20 days of incubation was significantly higher than that at 14 days of incubation. In the muscle, the lowest value for IGF-I gene expression was observed in meat-type chicken embryos. Regression analysis revealed that IGF-I gene expression was significantly correlated to the weights of the eyes and liver, but not the muscle. We conclude that there is little influence of strain on tissue IGF-I gene expression in chicken embryos during incubation but that tissue development in chicken embryos is nevertheless at least partly regulated by the change in IGF-I gene expression.

• Journal of Animal Science and Technology
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• v.62 no.3
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• pp.420-422
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• 2020

Streptococcus hyointestinalis B19 was isolated from chicken feces collected from local farm in Anseong, Korea. S. hyointestinalis B19 was shown to produce bacteriocin-like compounds exhibiting inhibitory activities against several pathogens including strains of Clostridium perfringens and Listeria monocytogenes. The whole genome of S. hyointestinalis B19 strain was sequenced using PacBio RS II platform. The genome comprised four contigs with a size of 2,217,061 bp. The DNA G + C content was found to be 42.95 mol%. Annotation results revealed 2,266 coding sequences (CDSs), 18 rRNAs, and 61 tRNA genes. Based on genome analysis, we found that the strain B19 possessed various genes associated with bacteriocin synthesis, modification, and transport.

• Journal of Microbiology and Biotechnology
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• v.32 no.10
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• pp.1307-1314
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• 2022

In this study, we sought to investigate the various characteristics of Salmonella spp. isolated from raw chicken meats available in Korean markets. The data collected, such as food source of isolation, sampling information, serotype, virulence, and genetic profile including sequence type, were registered in the database for further comparative analysis of the strains isolated from the traceback investigation samples. To characterize serotype, virulence and gene sequences, we examined 113 domestically distributed chicken meat samples for contamination with Salmonella spp. Phylogenetic analysis was conducted on 24 strains (21.2%) of Salmonella isolated from 113 commercially available chicken meats and by-products, using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Serotyping of the isolated Salmonella spp. revealed S. Enteritidis in 11 strains (45.8%), S. Virchow in 6 strains (25%), S. Montevideo in 2 strains (8.3%), S. Bsilla in 2 strains (8.3%), S. Bareilly in 1 strain (4.2%), S. Dessau in 1 strain (4.2%), and S. Albany in 1 strain (4.2%). The genetic correlation indicated that 24 isolated strains were classified into 18 clusters with a genetic similarity of 64.4-100% between them. Eleven isolated S. Enteritidis strains were classified into 9 genotypes with a sequence identity of 74.4%, whereas the most distantly related S. Virchow was divided into five genotypes with 85.9% identity. Here, the MLST analysis indicated that the major Sequence Type (ST) of the Salmonella spp. isolated from domestic chicken sold in Chungcheong Province belongs to the ST 11 and 16, which differs from the genotype of Salmonella isolated from imported chicken. The differential sequence characteristics can be a genetic marker for identifying causative bacteria for epidemiological investigations of food poisoning.

• Korean Journal of Veterinary Research
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• v.40 no.1
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• pp.101-109
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• 2000

Duck viral hepatitis is an acute, highly infectious viral disease of young dacklings aged from two days to three weeks. The significant lesion associated with the disease was enlarged liver including necrotic foci and numerous hemorrhagic spots. We have isolated five strains of duck hepatitis virus (DHV) from field cases showing about 20% mortality with a sign of opisthotonos. When a-day-old ducklings were intramuscularly inoculated with one of the isolates, 92% of the birds were died within 5 days. We attempted to develop an attenuated strain of duck hepatitis virus (DHV) using one of the isolates by serial chicken embryo passages. The propagation of DHV in chicken embryos was carried 140 passages. The virus titer increased gradually from the $21^{st}$ through the $50^{th}$ passage, but there was no significant increase of virus titer in subsequent passages after then. Through the serial passages, the virulence of the virus for chicken embryos was gradually increased but decreased for ducklings. The pathogenicity of the virus for ducklings was preserved up to the $21^{st}$ passage but disappeared at the $50^{th}$passage. An attenuated Korean isolate which was passaged 140 times in chicken embryos gave good protection in ducklings against both challenge infection to a Korean virulent strain and to a DHV-DRL strain, a type 1 reference strain of DHV, which indicated that the Korean isolates could be classified as DHV type 1. And the above results suggest that an attenuated Korean isolate can be used for developing a live DHV vaccine.

• Korean Journal of Poultry Science
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• v.46 no.4
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• pp.255-262
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• 2019

The micronutrients and flavor compounds of three new native chicken strains (A, C, and D) being developed in a breeding program (Golden Seed Project) were compared with a commercial native chicken strain (H) and the Baeksemi (W, white semi broiler). After 100 male chicks in each strains were reared for 5 weeks, the breast muscles from randomly selected 40 birds were analyzed at 8 replications. Native chicken strain A had greater amounts of α-tocopherol and α-tocotrienol compared with strain W. Native chicken strains showed higher contents of vitamin B₁₂ than Stain W. Stain H strain had the highest values of cholesterol content and strain D did the lowest. There was no different content of most minerals between native chickens (A, C, D, and H) and W, but Cu were more contained in native chicken strains compared with W. In terms of nucleotide-related flavor compounds, Stain A had the lowest content of hypoxanthine and strain D had highest inosine monophosphate. Native chicken strains had higher contents of umami-related free amino acids (glutamate and aspartate) than W. Among native chickens, strain A had more amounts in the contents of taurine, tasty flavor compounds, and certain vitamins, despite of the relatively low growth productivity. This result will provide information to select a strain with characteristic meat quality in a chicken breeding program.

• 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 Veterinary Research
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• v.51 no.3
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• pp.193-201
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• 2011

An attenuated vaccine strain AVR1/08 of Korean respiratory type of infectious bronchitis virus (IBV) was developed by 89th passages of IBV D85/06 strain in chicken eggs. The AVR1/08 strain had higher virus titer at least 20 times ($10^{1.3}$) than the parent virus D85/06 by egg inoculation method. The AVR1/08 strain had a single point mutation (S to Y) at position 56 of spike protein of IBV compared to parent virus IBV D85/06 strain. The mutation was observed consistently at viruses after 47th passage in chicken eggs. The AVR1/08 strain showed no virulence even after 6 passages in chickens and all chickens inoculated induced anti-IBV antibody 14 days after vaccination. The AVR1/08 strain had broad protective efficacy against QX type Korean nephropathogenic virus (Q43/06 strain), KM91 type Korean nephropathogenic virus (KM91 strain) and Korean respiratory virus (D85/06 strain). In contrast, Massachusetts (Mass) type attenuated vaccine strain H120 showed protection of 37.5 to 50% against these three viruses. Our results indicate that the AVR1/08 strain has potential as an attenuated vaccine effective in controlling IBVs circulating in Korea.

• Journal of Microbiology and Biotechnology
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• v.27 no.12
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• pp.2190-2198
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• 2017

Thermoactinomyces sp. strain YT06 was isolated from poultry compost and observed to degrade integral chicken feathers completely at $60^{\circ}C$, resulting in the formation of 3.24 mg/ml of free amino acids from 50 ml of culture containing 10 g/l chicken feathers. Strain YT06 could grow and secrete keratinase using feather as the only carbon and nitrogen sources without other supplement, but complementation of 10 g/l sucrose and 4 g/l $NaNO_3$ increased the production of the keratinolytic enzyme. The maximum protease activity obtained was 110 U/ml and for keratinase was 42 U/ml. The keratinase maintained active status over a broad pH (pH 8-11) and temperature ($60-75^{\circ}C$). It was inhibited by serine protease inhibitors and most metal ions; however, it could be stimulated by $Mn^{2+}$ and the surfactant Tween-20. A reductive agent (${\beta}$-mercaptoethanol) was observed to cleave the disulfide bond of keratin and improve the access of the enzyme to the keratinaceous substrate. Zymogram analysis showed that strain YT06 primarily secreted keratinase with a molecular mass of approximately 35 kDa. The active band was assessed by MALDI-TOF mass spectrometry and was observed to be completely identical to an alkaline serine protease from Thermoactinomyces sp. Gus2-1. Thermoactinomyces sp. strain YT06 shows great potential as a novel candidate in enzymatic processing of hard-to-degrade proteins into high-value products, such as keratinous wastes.