• Proceedings of the Korea Society of Poultry Science Conference
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• 2004.11a
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• pp.53-68
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• 2004

Eggshell quality is one of the most important factors that influence hatchability. The porosity and overall quality of eggshell have a very significant effect on exchange of vital gas (carbon dioxide and oxygen) between the developing embryo and the air during incubation. Thin-shelled eggs showed the greater weight loss than do thick-shelled eggs. causing the chick to have difficulty in hatching. Thin-shelled eggs also have a much greater chance of being cracked during handling. On the other hand. thick-shelled eggs showed the higher hatchability as a result of greater fertility and lower intermediate and late embryonic mortalities. Even a small percentage improvement in the eggshell quality could result in significant saving to the breeder industry in an increasingly competitive environment. Many factors including nutrition. management practices, environmental conditions and breeding are known to be related to eggshell quality. In this review brief accounts of each factor associated with eggshell quality and hatchability were provided. We conducted three experiments to investigate the effects of dietary Ca. vitamin D3 metabolite and some bioactive materials on eggshell quality and hatching egg production. The results of our studies showed that relatively high levels of dietary Ca in combination with 25-hydroxycholecalciferol had beneficial effects on improving eggshell quality and reproductive performances in aged egg-type breeder hens. It was also suggested that the proper use of some feed additives such as isoflavon and chitosan might provide means of improving eggshell quality and reproductive performances in aged egg-type breeder hens.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2005.11a
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• pp.62-63
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• 2005

Korean Ogol Chicken is a natural treasure in Korea and expected to be a valuable genetics resource in the world. As an initial step to investigate the genetic structures of this breed, phylogenetic analysis has been performed using mitochondrial DNA (mtDNA) sequence variations. Total 30 Korean Ogol Chickens were investigated in this study and they were grouped into 4 haplotypes, consisting 11 birds in the largest haplotype. Based on the phylogenetic analysis, chicken breeds were divided into three major groups and Korean Ogol Chicken were appeared all of these three groups indicating their large genetic mtDNA diversity. These results will be used for making breeding and conservation strategies for this breed.

• Korean Journal of Poultry Science
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• v.25 no.3
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• pp.103-111
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• 1998

This study was carried out to estirnate the heritabilities and genetic correlations on egg shape index and internal egg qualities ; shell thickness, alburnin heights and Haugh units for breeding plan and selection in Korean native chicken. Data analyzed were the records of 46,908 eggs from 43() layers from April, 1994 to September, 1995. The egg shape index at the first egg, 300 days and 500 days of ages were 74.771, 74.468 and 73.702; the shell thickness were 0.345, 0.344 and 0. 334mm; the alburnen heights were 6.579, 6.130 and 5.318mm; the Haugh units were 86.859, 81.014 and 73.565 respectively. The heritability estimates of egg shape index and internal egg qualities based on the variance of sire, dam and combined components at 300 days of age were 0.136, 0.954 and 0.545 for egg shape index; 0.201, 0.622 and 0.421 for shell thickness; 0.410, 0.961 and 0.633 for albumen height ; 0.353, 0.962 and': 0.608 for Haugh units. The genetic correlation coefficient between shell thickness and albumen height was -0.044~0.824; 0.016~0.949 between Haugh units and shell thickness 0.313~0.941 between albumen height and Haugh units, respectively.

• Korean Journal of Poultry Science
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• v.27 no.3
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• pp.215-220
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• 2000

This experiment was carried out to investigate the effect of reproductive ability on weeks and body weights of broiler breeder males. From 26 to 36 week, volume of semen and body weight were increased. Total concentration was highest at 36 week(P〈0.05), being 21.14$\times$10(sup)8 cells. Mean of total concentration was 14.66$\times$10(sup)8 cells and 11.59$\times$10(sup)8 cells in young(26∼55 weeks) and old(60∼89 weeks) broiler breeder males, respectively. Percentage of fertile eggs, viability and hatchability on weeks were 96.33, 89.55, 86.25% in the young broiler breeder males, 94.84, 91.73 and 86.97% the old broiler breeder males, respectively. The values were not significantly different between the young and old broiler breeder males. While the body weight of cocks was less than 3.5kg, it was not possible to collect semen. Semen collection rate was the best in 4.5∼5.0kg of males, total concentration was highest in 5.0∼5.5kg, volume of semen was highest in 5.5∼6.0kg body weight. More than 80% of the males were in the range of 4∼6kg body weight. Sperm motility was acceptable for breeding.

• Korean Journal of Poultry Science
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• v.36 no.4
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• pp.317-322
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• 2009

The chicken major histocompatibility complex (MHC) is known to be associated with disease resistance and susceptibility to several pathogens. The microsatellite marker LEI0258 is physically located between the BG and BF of MHC region and variations near this marker have been well documented. In this report, the LEI0258 marker was used to find specific alleles for the Korean native chicken. The MHC haplotype was analyzed by PCR screening and sequencing of LEI0258 region in four different breeds including black Korean native chicken, brown Korean native chicken, Cornish and Rhode island red. The serologically same MHC haplotypes showed the differences in repeat numbers, a few indels or single nucleotide polymorphisms by sequencing analysis. Even though we could not identify specific alleles for Korean native chickens, the genotypes analyzed in these breeds can give valuable information for the relationships with disease resistance and establishment of breeding strategies for the Korean native chicken.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.3
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• pp.401-412
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• 2000

Like other livestock, monogastric animals are essential components of the farming systems in the tropical countries. Pigs, chicken and ducks are by far the most important animals in the culture of the peoples of developing countries in the tropics. Traditionally these animals are raised in small farms and they are also the bulk producers of meat, eggs etc. in the tropics. In many countries the farmers of these small farms are unable to meet the requirement set by financial institution and other loan giving agencies for agricultural loan. Thus, the small farmers can get neither the opportunity to generate sufficient income to support the family nor to extend the livestock activities. The production systems are characterized by small number of animals with no or minimal inputs, low outputs and periodic destruction of animals by disease. Typically the litter size or flocks are small in number with each household containing 5-6 pigs and 7-10 poultry. Animals are owned by individual households and mostly maintained under a scavenging systems with little or no inputs for housing, feeding or health care. Because of the nature of this production system, productivity of these animals is rather low. The low level of inputs is due to a lack of capital and a low risk oriented outlook. The feed resource base for monogastric is scavenging and consists of household waste, roots and tuber, grain by-products and anything edible found in the immediate environment. Usually farmers select breeding gilts from their own female piglets or to a lesser extent, buy them from neighbors for natural mating. As regards poultry attempts have been made to increase egg and meat production by improving local poultry birds by upgrading and crossbreeding with exotic germ plasma in the tropics. Animal disease present a major constraint to animal production in the tropical region and the extent of the losses due to disease is very high.

• Korean Journal of Poultry Science
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• v.7 no.2
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• pp.28-36
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• 1980

This study was carried out to estimate combining abilitie or economic traits in layer chickens. The data used in this study were the record of 10 single crosses produced by half diallel cross of 5 lines of Single Comb White Leghorns, such as A, B, C, K and S lines. Total 720 progenies of the crosses were reared at the Poultry Breeding Farm, College of Agriculture, Seoul National University from Feb. 1979 to August, 1980. Combining abilities were estimated by Grilling's mathematical model for the traits; age the first egg, total egg number, egg weight and body weight. The results attained from the studies were summarized as follows; In estimate of combining ability, an age at first egg of BS cross was largely due to significiantly higher general combining ability (G. C. A.) effect of B and S strains than Cand K strains in G. C. A. effect, and to specific combining ability (S. C. A) effect of B and S-trains. AB and BS crosses showed the highest egg Production. AB cross performance was result from high G.C.A. effect of A ana B strains. BS cross performance was result from high G. C. A. effect of B and high S. C. A. effect of BS cross. Specific combining ability effect in egg. weight was not statiscally significiant, but S strain showed high G. C. A. effect. A and B strains in body weight showed significantly low C. C. A. effect. From the above results, BS cross in an age at first egg, AB and BS crosses in egg Production, S strain in egg weight and AB cross in body weight were superior to other strains or crosses.

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.407-420
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• 2022

Chicken dominates meat consumption because it is low in fat and high in protein and has less or no religious and cultural barriers. Recently, meat quality traits have become the focus of the poultry industry more than ever. Currently, poultry farming is focusing on meat quality to satisfy meat consumer preferences, which are mostly based on high-quality proteins and a low proportion of saturated fatty acids. Meat quality traits are polygenic traits controlled by many genes. Thus, it is difficult to improve these traits using the conventional selection method because of their low to moderate heritability. These traits include pH, colour, drop loss, tenderness, intramuscular fat (IMF), water-holding capacity, flavour, and many others. Genome-wide association studies (GWAS) are an efficient genomic tool that identifies the genomic regions and potential candidate genes related to meat quality traits. Due to their impact on the economy, meat quality traits are used as selection criteria in breeding programs. Various genes and markers related to meat quality traits in chickens have been identified. In chickens, GWAS have been successfully done for intramuscular fat (IMF) content, ultimate pH (pHu) and meat and skin colour. Moreover, GWAS have identified 7, 4, 4 and 6 potential candidate genes for IMF, pHu, meat colour and skin colour, respectively. Therefore, the current review summarizes the significant genes identified by genome-wide association studies for meat quality traits in chickens.

• Journal of Korean Society of Rural Planning
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• v.26 no.4
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• pp.67-79
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• 2020

As globalization, international cooperation has grown in importance. In accordance with this trend, Korea has been receiving high demands from international organizations about expanding the scale of Official Development Assistance(ODA) in line with its improved national status. In addition, in the economic aspect of Korea, the ODA project is expected to provide new growth opportunities in the mid- to long-term by promoting cooperation with developing countries. Uganda is an area with high strategic value due to good agricultural conditions and favorable geographical conditions. The poultry industry is a business that is generally carried out to the Ugandan, but due to economic problems such as initial investment cost, most of them have raised poultry on a small scale which is not enough for main income. This paper proposes the construction and operation plan of adapting to small poultry farms in the village-intensive type to sustainable income for residents in Uganda through ODA project in Korea's agricultural technology. The economic feasibility was analyzed from the long-term perspective when the initial construction cost was supported or not and the poultry species ratio was adjusted in terms of initial and operating costs. Economic analysis was performed using Net Present Value(NPV) method. As of after 10 years, when operating in the form of shifting kuroiler to layers, it was estimated to earn about 700,000 ugx more than when only kuroiler is raised, and it is able to reduce about 14 million ugx from the initial cost than when only raising layers. As of 20 years, the most profitables scenario was the breeding of 100 kuroilers and 400 layers methods. however, this case was anlayzed to be unsuitable for Uganda farmers, with initial costs more than three times higher than the shifting method of the kuroiler to layers. If the initial construction cost is supported by ODA project, the initial investment cost can be recovered in the first year with the shifting method, whereas raising only layers take two years to recoup the cost. In the meantime, when studying livestock industry in Uganda, it was examined by relying on statistical data, but this paper is meaningful in that it predicted how much it is economically effective based on field experience.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.11
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• pp.1732-1740
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• 2020

Objective: The objectives of this study were to investigate the genetic diversity, population structure and relatedness among the five chicken populations of Bangladesh using microsatellite markers. Methods: A total of 161 individuals representing 5 chicken populations (non-descript Deshi [ND], naked neck [NN], hilly [HI], Aseel [AS], and red jungle fowl [JF]) were included in this study to investigate genetic diversity measures, population structure, genetic distance and phylogenetic relationships. Genotyping was performed using 16 selected polymorphic microsatellite markers distributed across 10 chromosomes. Results: The average observed and expected heterozygosity, mean number of alleles and polymorphic information content were found to be 0.67±0.01, 0.70±0.01, 10.7 and 0.748, respectively in the studied populations. The estimated overall fixation index across the loci (F), heterozygote deficiency within (F_IS) and among (F_IT) chicken populations were 0.04±0.02, 0.05 and 0.16, respectively. Analysis of molecular variance analysis revealed 88.07% of the total genetic diversity was accounted for within population variation and the rest 11.93% was incurred with population differentiation (F_ST). The highest pairwise genetic distance (0.154) was found between ND and AS while the lowest distance was between JF and AS (0.084). Structure analysis depicted that the studied samples can be categorized into four distinct types or varieties (ΔK = 3.74) such as ND, NN, and HI where AS and JF clustered together as an admixed population. The Neighbor-Joining phylogenetic tree and discriminant analysis of principal component also showed close relatedness among three chicken varieties namely AS, HI, and JF. Conclusion: The results reflected that indigenous chicken of Bangladesh still possess rich genetic diversity but weak differentiation among the studied populations. This finding provides some important insight on genetic diversity measures that could support the designing and implementing of future breeding plans for indigenous chickens of Bangladesh.