• Korean Journal of Poultry Science
• /
• v.43 no.2
• /
• pp.63-76
• /
• 2016

The genetic diversity of Korean native chicken is important for conservation of native chicken breeds and developing economically valuable traits in Korea. In this review, various types of genetic markers using Korean native chickens were investigated, which are mtDNA variations, microsatellite markers, markers in Major Histocompatibility Complex (MHC), and single nucleotide polymorphisms (SNPs). These genetic markers are suitable for breed discrimination and diversity studies because of their high polymorphism status. Thus, the purpose of this study was to summarize the genetic markers developed in the Korean native chickens and diversity studies using these breeds. Ultimately, these markers can be used for the future studies for understanding of genetic characteristics.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.3
• /
• pp.331-339
• /
• 2008

The genetic structure and diversity of 15 Chinese indigenous chicken breeds was investigated using 29 microsatellite markers. The total number of birds examined was 542, on average 36 birds per breed. A total of 277 alleles (mean number 9.55 alleles per locus, ranging from 2 to 25) was observed. All populations showed high levels of heterozygosity with the lowest estimate of 0.440 for the Gushi chickens, and the highest one of 0.644 observed for Wannan Three-yellow chickens. The global heterozygote deficit across all populations (FIT) amounted to 0.180 (p<0.001). About 16% of the total genetic variability originated from differences between breeds, with all loci contributing significantly to this differentiation. An unrooted consensus tree was constructed using the Neighbour-Joining method and pair-wise distances based on marker estimated kinships. Two main groups were found. The heavy-body type populations grouped together in one cluster while the light-body type populations formed the second cluster. The STRUCTURE software was used to assess genetic clustering of these chicken breeds. Similar to the phylogenetic analysis, the heavy-body type and light-body type populations separated first. Clustering analysis provided an accurate representation of the current genetic relations among the breeds. Remarkably similar breed rankings were obtained with all methods.

• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.10
• /
• pp.1558-1564
• /
• 2018

Objective: We report monitoring conservation effect for a Chinese indigenous chicken (Langshan) breed using major histocompatibility complex (MHC) and DNA barcords. Methods: The full length of MHC B-G gene and mitochondrial cytochrome oxidase I (COI) gene in generations 0, 5, 10, 15, 16, and 17 was measured using re-sequencing and sequencing procedures, respectively. Results: There were 292 single nucleotide polymorphisms of MHC B-G gene identified in six generations. Heterozygosity (He) and polymorphic information content (PIC) of MHC B-G gene in generations 10, 15, 16, and 17 remained stable. He and PIC of MHC B-G gene were different in six generations, with G10, G15, G16, G17 >G5>G0 (p<0.05). For the COI gene, there were five haplotypes in generations 0, 5, 10, 15, 16, and 17. Where Hap2 and Hap4 were the shared haplotypes, 164 individuals shared Hap2 haplotypes, while Hap1 and Hap3 were the shared haplotypes in generations 0 and 5 and Hap5 was a shared haplotype in generations 10, 15, 16, and 17. The sequence of COI gene in 6 generations was tested by Tajima's and D value, and the results were not significant, which were consistent with neutral mutation. There were no differences in generations 10, 15, 16, and 17for measured phenotypic traits. In other generations, for annual egg production, with G5, G10, G15, G16, G17>G0 (p<0.05). For age at the first egg and age at sexual maturity, with G10, G15, G16, G17>G5>G0 (p<0.05). Conclusion: Combined with the results of COI gene DNA barcodes, MHC B-G gene, and phenotypic traits we can see that genetic diversity remained stable from generations 10 to 17 and the equimultiple random matching pedigrees conservation population conservation effect of Langshan chicken was effective as measured by these criteria.

• Korean Journal of Poultry Science
• /
• v.38 no.2
• /
• pp.81-87
• /
• 2011

The study was conducted to select and optimize microsatellite (MS) markers for evaluate Korean Native Chicken (KNC) breeds in order to provide standard for the classification and breed definition of the indigenous breeds. The study also aimed to characterize and classify each KNC populations for inventory and management of avian genetic resources. A total of 462 chickens from 11 populations of chicken breeds including eight KNC breeds and three commercial chicken breeds were analyzed with 19 MS markers. KNC breeds, especially Long-Tail Chicken breeds, formed separate cluster from those commercial chicken breeds. Genetic distances between KNC populations (0.11~0.18) were relatively shorter. Genetic uniformity of KNC (except KNCR breed) (0.86~0.88) were higher than that of commercial breeds (except Cornish) (0.95~0.97). On the other hand, genetic uniformity of KNC Long Tail (KNCLT) were relatively higher (0.91~0.97). The result can be used to evaluate and manage animal genetic resources at national scale.

• Asian-Australasian Journal of Animal Sciences
• /
• v.26 no.5
• /
• pp.732-742
• /
• 2013

Flavour comprises mainly of taste and aroma and is involved in consumers' meat-buying behavior and preferences. Chicken meat flavour is supposed to be affected by a number of ante- and post-mortem factors, including breed, diet, post-mortem ageing, method of cooking, etc. Additionally, chicken meat is more susceptible to quality deterioration mainly due to lipid oxidation with resulting off-flavours. Therefore, the intent of this paper is to highlight the mechanisms and chemical compounds responsible for chicken meat flavour and off-flavour development to help producers in producing the most flavourful and consistent product possible. Chicken meat flavour is thermally derived and the Maillard reaction, thermal degradation of lipids, and interaction between these 2 reactions are mainly responsible for the generation of flavour and aroma compounds. The reaction of cysteine and sugar can lead to characteristic meat flavour specially for chicken and pork. Volatile compounds including 2-methyl-3-furanthiol, 2-furfurylthiol, methionol, 2,4,5-trimethyl-thiazole, nonanol, 2-trans-nonenal, and other compounds have been identified as important for the flavour of chicken. However 2-methyl-3-furanthiol is considered as the most vital chemical compound for chicken flavour development. In addition, a large number of heterocyclic compounds are formed when higher temperature and low moisture conditions are used during certain cooking methods of chicken meat such as roasting, grilling, frying or pressure cooking compared to boiled chicken meat. Major volatile compounds responsible for fried chicken are 3,5-dimethyl-1,2,4-trithiolanes, 2,4,6-trimethylperhydro-1,3,5-dithiazines, 3,5-diisobutyl-1,2,4-trithiolane, 3-methyl-5-butyl-1,2,4-trithiolane, 3-methyl-5-pentyl-1,2,4-trithiolane, 2,4-decadienal and trans-4,5-epoxy-trans-2-decenal. Alkylpyrazines were reported in the flavours of fried chicken and roasted chicken but not in chicken broth. The main reason for flavour deterioration and formation of undesirable "warmed over flavour" in chicken meat products are supposed to be the lack of ${\alpha}$-tocopherol in chicken meat.

• Korean Journal of Poultry Science
• /
• v.47 no.2
• /
• pp.95-105
• /
• 2020

This study presents the production characteristics and physiological characteristics of five Korean native chicken (KNC) breeds consisting of Hwanggalsaek Jaeraejong (HJ), Korean Rhode Island Red (KR), Korean White Leghorn (KL), Korean Brown Cornish (KC), and Korean Ogye (KO). We investigated their production performances, vitalities, and stress responses. We measured the survival rate, body weight, age at first egg-laying, hen-day egg production, egg weight, amount of telomeric DNA, heterophil-lymphocyte ratio (H/L ratio), and heat shock protein (HSP)-70, HSP-90α and HSP-90β gene expression levels for 493 KNCs. The survival rate was highest in KR, and lowest in KO. Body weights were steadily high in the order of KC, KR, HJ, KO and KL. Average hen-day egg production was highest in KL, and lowest in KC. While the amount of telomeric DNA was highest in KR, and lowest in KC. Furthermore, both the H/L ratio and the HSP-90β gene expression level were highest in KC, and lowest in KR. These results indicated that the KR breed was highly resistant to stress, whereas KC was more susceptible to stress. Taken together, it is considered that with improvements the KC breed would be more suited to be used as a Korean broiler breed while KL would be more appropriately used as a Korean layer breed. In addition, it is considered that the KR breed is appropriate to be used as a maternal chicken breeder based on good production capacity and excellent robustness, while the HJ breed is desirable to be improved as a high-quality Korean meat breed based on its excellent meat quality.

• Korean Journal of Poultry Science
• /
• v.47 no.4
• /
• pp.237-245
• /
• 2020

This study investigated the effects of breed, laying age, and egg storage period on hatching performance. Eggs were collected from early laying period (27 to 29 weeks old) and late laying period (50 to 52 weeks old) in Hwanggalsaek Jaeraejong, Korean Rhode Island Red, and Korean White Leghorn chicken breeds. Eggs laid for each period were stored for 3, 7 and 14 days and then hatched. Fertility, hatchability, and embryonic mortality were observed to determine the hatching performance. The results showed that hatching performance was affected by breed, laying age, and egg storage period with independently or interactively. The Korean Rhode Island Red breed had the lowest hatching performance. Hatchability and early embryonic mortality rate increased in early laying period eggs compared to the late laying period, but the late embryonic mortality rate increased in late laying period eggs. Additionally, hatching performance decreased as the egg storage period increased. Using breed-specific hatching management techniques, avoiding late laying period eggs, and shortening the egg storage period to seven days after laying may improve the hatching performance.

• Korean Journal of Poultry Science
• /
• v.48 no.1
• /
• pp.1-12
• /
• 2021

We investigated the effects of breed, laying age, and egg storage period on the vitality of chicks using the Hwanggalsaek Jaeraejong, Korean Rhode Island Red, and Korean White Leghorn chicken breeds. Their eggs were collected during the early laying period (27~29 weeks) and late laying period (50~52 weeks) and were stored for 3 days, 7 days and 14 days. After the eggs hatched, the hatching time, production performance, and organ weight of chicks were investigated. IL-6 gene expression level and relative length of telomeres were analyzed to determine the physiological activity of the chicks. HSP gene expression level and heterophil to lymphocytes ratio were also analyzed to examine the degree of stress response in the chicks. The results showed that breed and laying age influenced the vitality of chicks, but the egg storage period did not. Korean Leghorn chicks were considered the weakest breed in terms of vitality owing to their low survival rate, small heart size, low physiological activity, and high stress response level. Although the survival rate of chicks produced in the early laying period was low, their high physiological activity and low stress response indicated that they had a high vitality than the chicks produced in the late laying period. In conclusion, to obtain chicks with high vitality, it would be desirable to select a high vitality breed and avoid the use of chicks produced in the late laying period.

• Asian-Australasian Journal of Animal Sciences
• /
• v.27 no.3
• /
• pp.398-405
• /
• 2014

This study was conducted to compare growth performance, carcass characteristics and meat quality of 4 breeds of local chicken. A total of 480 1-d-old chicks were distributed to 16 pens, with 4 treatments of breed, 4 replicates and 30 chicks per pen. Three Korean local breeds of white-mini broiler, Hanhyup-3-ho, and Woorimatdag, and a breed of silky fowl were raised under identical rearing and feeding conditions for 31-d, 37-d, 36-d, and 59-d, respectively. The BW and feed consumption on a pen basis were weekly measured for all pens, and ADFI, ADG and gain:feed were calculated for each pen. The ADFI and ADG of 3 breeds of Korean local chicken were greater than those of silky fowl (p<0.05). Within the Korean local breeds, ADFI of white-mini broiler was the highest (p<0.05), and ADG of Hanhyup-3-ho and white-mini broiler was the highest (p<0.05). Gain:feed of silky fowl was less than that of the 3 breeds of Korean local chicken. The carcass and breast yield of white-mini broiler were the greater than those of other breeds (p<0.05). The breast meat color (CIE $L^*$, $a^*$, and $b^*$) of 3 breeds of Korean local chicken were higher than that of silky fowl (p<0.05). The breast meat of Hanhyup-3-ho had greater cooking loss (p<0.05), whereas water holding capacity and pH were less than those of other breeds (p<0.05). The color score of 3 breeds of Korean local chicken was higher than that of silky fowl (p<0.05). Woorimatdag had a higher score on tenderness (p<0.05), whereas flavor score was less than that of other breeds (p<0.05). In conclusion, 4 local breeds of chicken have some unique features and seem to have more advantages, and this information can help consumers who prefer healthy and premium chicken meat.

• The Korean Journal of Food And Nutrition
• /
• v.30 no.3
• /
• pp.552-559
• /
• 2017

This research investigated quality characteristic and sensual characteristic of Chilhyanggye recipe comparing to general Samgyetang, through restoring the recipe recorded in old documents. pH appeared 6.60, high in control group, while Ungchu and Baekssemi Samgyetang displayed respectively 6.42, 6.41, no significant difference from control group, however Ungchu and Baekssemi chilhyanggye displayed 5.89, 5.90, significantly low. Brightness of breast appeared significantly high in Baekssemi Samgyetang however reddishiness appeared high in Ungchu Chilhyanggye, while yellowishness appeared high in Baekssemi Chilhyanggye compared to other groups. Brightness of chicken leg appeared highest in Baekssemi Chilhyanggye, significantly higher than other groups (p<0.05). Reddishness appeared higher in control group, however appeared low in Samgyetang. Brightness value of soup appeared very high in control group, Ungchu, and Baekssemi Chilhyanggye, which seems to be due to difference in chicken recipe. In case of reddishness, Ungchu Chilhyanggye appeared the highest, and significantly high in order of Baekssemi Chilhyanggye, Baekssemi Samgyetang (p<0.05). Yellowishness appeared significantly high in control group (p<0.05). Hardness of intensity of breast appeared highest in Ungchu Samgyetang and Ungchu Chilhyanggye, and in order of Baekssemi Samgyetang, Baekssemi Chilhyanggye, which seems to be the result of diversity of breed and using vinegar in recipe. Investigation of preference appeared significantly high in color, fragrance, taste, and overall preference in Ungchu and Baekssemi Chilhyanggye compared to control group and Samgyetang (p<0.001). Ungchu Chilhyanggyetang appeared significantly high in overall preference (p<0.001). Calorie appeared higher in Baekssemi compared to Ungchu, while Samgyetang displayed higher value than Chilhyanggye. Carbohydrate appeared higher in Samgyetang than Chilhyanggye. Crude protein content appeared higher in Ungchu breed than Baekssemi breed, on the contrary, crude fat appeared low. Saturated fat and cholesterol apepared lower in Ungchu than Baekssemi.