• Korean Journal of Poultry Science
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• v.28 no.3
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• pp.225-229
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• 2001

This experiment was carried out to investigate the effects of storage temperature and time on hatch-ability of the commercial Ross broiler breeder eggs. In Trial 1,720 eggs collected in the morning were allotted to four storage time treatments (3, 5, 7 and 9 days), with three replicates per treatment. The storage temperature was fixed at $4^{\circ}C$. In Trials 2 and 3, similar protocol was used as in Trial 1 except that the storage temperature was fixed at $17^{\circ}C$ and $28^{\circ}C$respectively. In Trial 1, hatchability was significantly (P<0.05) reduced when the eggs were stored more than 3 days. In Trial 2, no significant difference was found among all treatments, indicating that, at 17$^{\circ}C$ storage temperature, the eggs could be stored up to 9 days without reducing hatchability. In Trial 3, however, hatchability of eggs stored for 9 days was significantly reduced compared to the other treatments. In conclusion, we found out that optimum hatchability can be achieved with a storage temperature of $17^{\circ}C$ for Ross broiler eggs stored for up to 9 days.

• Korean Journal of Poultry Science
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• v.27 no.1
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• pp.73-78
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• 2000

Embryonic stem (ES) cells are pluripotent cell lines, which derived from preimplantation embryo. These cells have been used as a vehicle of foreign DNA for production of transgenic mammals. this experiment was performed to examined the possible use of blastodermal cells derived from hen's egg for germline manipulation. Stage X blsdtodermal cells isolated from fertilized eggs were cultured in DMEM containing 15% fetal calf serum. Blastodermal cells wre co-cultured on the chicken embryonic fibroblast (CEF) or mouse embryonic fibroblast(MEF) cells. to examine the effects of growth factors on stem cell growth, bFGF and LIF were added. There was no significant difference in colony formation of putative ES cells between CEF and MEF as a feederlayer, but the addition of growth factors enhanced the proliferation and inhibited differentiation of blastodermal cells. To characterize the cell colonies as a putative ES cells, putative embryonic cell colonies were stained by periodic acid Schiffs (PAS) reagent. The putative ES cell colonies showed intensive positive reaction similar to the property of undifferentiated PGC upto 20days in vitro, but not in other cell types. this result demonstrates that PAS-positive cell colonies may be used for the study of establishment of chicken ES cell lines for the production of transgenic chicken.

• Korean Journal of Poultry Science
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• v.6 no.1
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• pp.31-37
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• 1979

The propose of the present study was to evaluate the relative economic importance of the major Production traits in laying hens. Based on the results of this study, it was showed that feed requirement, average egg weight and hen-housed e99 Production influenced greatly on the income over feed and chick cost.

• Korean Journal of Poultry Science
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• v.16 no.4
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• pp.209-217
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• 1989

This study was carried out to obtain the information on the genetic characters of Korean native fowls. The data for this study was collected from fowls located at the Gyunggi, Chunscheong, Yeongnam and Jeju area from March, 1989 to November, 1989. The morphology, genetic characters and economic traits of fowls were investigated. Followings are the major results obtained from this study. 1. The morphology and genetic characters of Korean native fowls are similar to those of brown Leghorn, 2. Colored fowls outnumbered white fowls by 402 to 38 in feather color, and wild type fowls outnumbered black fowls by 317 to 38 in feather pattern. 3. For morphology of chromosomes, chromosome size and shape of Korean native fowls were similar to those of other breeds. 4. Body weights of male was 1.2-1.6kg, and of female 1.5-1.9 kg. Hen-housed egg production was 80-120 eggs.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.7
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• pp.1135-1155
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• 2007

Selenium is considered to be one of the most controversial trace elements. On the one hand, it is toxic at high doses and there is a great body of information related to environmental issues of Se contamination. On the other hand, Se deficiency is a global problem related to an increased susceptibility to various diseases of animals and humans and decreased productive and reproductive performance of farm animals. Optimisation of Se nutrition of poultry and farm animals will result in increased efficiency of egg, meat and milk production and even more important, will improve quality. From the data presented in the review it is clear that the main lesson which we have to learn from nature is how to use organic selenium in animal and human diets. Selenium-enriched yeast (Sel-Plex) is the result of such a lesson and it is just a matter of time before animal nutrition moves completely from using ineffective sodium selenite to organic selenium. Other lessons from nature will follow. Recent advances in genomics and proteomics, in association with descriptions of new selenoproteins, will be a driving force in reconsidering old approaches related to Se nutrition. Probably 90% of all Se research has been conducted with sodium selenite and we now understand that the natural form of selenium is different. The main advances in Se status assessment and Se requirements were established based on the activity of glutathione peroxidase (GSH-Px), an enzyme which for many years was considered to be the main selenoprotein. Recently it was discovered that it is only one of at least 25 various selenoproteins. Se research and practical applications are developing quickly and they are very exciting and promising.

• Korean Journal of Veterinary Research
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• v.51 no.1
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• pp.21-28
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• 2011

Salmonella Enteritidis (SE) has been a major causative agent of food-borne human disease due to consumption of contaminated eggs and poultry meat. To prevent SE infection in poultry, and therefore minimize human infections, vaccination with either killed or live SE vaccine is suggested. We evaluated a newly developed killed bacterin using a representative SE isolate in Korea. Among pool of SE isolates, two highly virulent isolates (the one isolate from chicken, the other from human) were selected by measuring mortality in mouse and chickens administered. The chickens were injected intramuscularly with killed vaccine and were challenged with highly virulent SE strain 3 week after vaccination. The recovered colony count (cfu/g) of spleen and cecal content in the vaccinated groups was reduced compared with those of the unvaccinated control group. The antibody level in the vaccinated groups was higher at 3 week post vaccination. These results indicate that vaccination with killed vaccine was effective in preventing the infection of virulent SE. Further study for a large number of layers should be needed for the effect of egg production, SE shedding in feces, persistence of antibody level.

• Korean Journal of Community Nutrition
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• v.13 no.3
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• pp.439-452
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• 2008

This study was conducted to identify major dietary patterns of generally healthy Korean middle-aged women and to examine associations of the dietary patterns with socio-demographic, psychological, and physical characteristics. Data were drawn from the 2001 Korean National Health and Nutrition Examination Survey (KNHANES), which is an ongoing national surveillance system. Healthy female subjects aged 40-64 years and provided the health interview examination and food frequency questionnaire (FFQ) data were included. We conducted factor analysis based on daily mean intake frequency of 26 food groups and identified 3 major dietary patterns, healthy, convenient, and alcohol-animal. The healthy pattern was characterized by higher intakes of fish, seafood, poultry, mushroom, seaweed, vegetable, tomato, potato, and fruit, the convenient pattern by processed meat and fish, ramen, noodle and rice cake, sweet snack, egg, bread, and fast food, and the alcohol-animal pattern by alcohol, poultry, meat, and fish. The healthy pattern was significantly related with higher socio-economic status, more stable family structure, healthier mentality, and sounder status of anthropometric and biochemical variables. Those with higher factor scores for the convenience pattern were found to be younger and having higher socio-economic status, higher subjective levels of health, and lower subjective levels of worry on health. Several physical characteristics significantly improved as the levels of the convenience pattern increased. The alcohol-animal pattern was significantly associated with several socio-demographic characteristics including a low education level, a young age, a small family size, and blue-collar jobs. Public health policy makers can utilize the study findings to select prior target populations with higher needs and to tailor dietary behavioral messages to lower chronic disease risks among Korean middle-aged women.

• Korean Journal of Poultry Science
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• v.42 no.3
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• pp.239-245
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• 2015

Transgenic animals have been widely used for developmental biology studies, as disease models, and even in industry such as transgenic bioreactor animals. For transgenic birds, quail has the great advantages of small body size, short generation time, and frequent egg production. To date, retroviral or lentiviral transduction has been used to generate transgenic quail for various purposes. However, the efficiency of transgenic offspring production with these methods is relatively low and viral vector usage has safety issues. Unfortunately, non-viral transgenesis has not been established in quail due to a deficiency of stem cell and germ cell culture systems. In this study, we established a direct in ovo lipofection method that could be used to create transgenic quail without germline-competent cells or viruses. To optimize the injection stage during embryo development, the liposome complex (containing piggyBacCMV-GFP and transposase plasmids) was introduced into an embryonic blood vessel at 50 hr, 55 hr or 60 hr. GFP expression was detected in various tissues (heart, kidney, liver and stomach) on day 12 of incubation under a fluorescence microscope. Additionally, GFP-positive cells were detected in the recipient embryonic gonads. In conclusion, the direct in ovo lipofection method with the piggyBac transposon could be an efficient and useful tool for generating transgenic quail.

• Animal Bioscience
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• v.36 no.11
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• pp.1727-1737
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• 2023

Objective: The poultry industry is a primary source of animal protein worldwide. The gut microbiota of poultry birds, such as chickens and ducks, is critical in maintaining their health, growth, and productivity. This study aimed to identify longitudinal changes in the gut microbiota of laying hens from birth to the pre-laying stage. Methods: From a total of 80 Hy-Line Brown laying hens, birds were selected based on weight at equal intervals to collect feces (n = 20 per growth) and ileal contents (n = 10 per growth) for each growth stage (days 10, 21, 58, and 101). The V4 regions of the 16S rRNA gene were amplified after extracting DNA from feces and ileal contents. Amplicon sequencing was performed using Illumina, followed by analysis. Results: Microbial diversity increased with growth stages, regardless of sampling sites. Microbial community analysis indicated that Firmicutes, Proteobacteria, and Bacteroidetes were the dominant phyla in the feces and ileal. The abundance of Lactobacillus was highest on day 10, and that of Escherichia-shigella was higher on day 21 than those at the other stages at the genus level (for the feces and ileal contents; p<0.05). Furthermore, Turicibacter was the most abundant genus after changing feed (for the feces and ileal contents; p<0.05). The fecal Ruminococcus torques and ileal Lysinibacillus were negatively correlated with the body weights of chickens (p<0.05). Conclusion: The gut microbiota of laying hens changes during the four growth stages, and interactions between microbiota and feed may be present. Our findings provide valuable data for understanding the gut microbiota of laying hens at various growth stages and future applied studies.

• Korean Journal of Poultry Science
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• v.37 no.1
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• pp.51-62
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• 2010

This study was conducted to investigate the effects of dietary supplementation of multiple probiotics on the performance, small intestinal microflora and immune response in laying hens and broilers. In Exp.1, a total of 800, 82 wk old Hy-line Brown$^{(R)}$ laying hens were assigned to one of the following five dietary treatment; Control, Antibiotics (avilamycin 6 ppm), Probiotics; PB-M (Micro-ferm$^{(R)}$ 0.2%), PB-L (Lacto-sacc$^{(R)}$ 0.1%), PB-Y (Y University probiotics 0.2%). Each treatment was replicated eight times with 20 birds in each replicate and two birds were housed in each cage. Twenty birds units were arranged according to completely randomized block design. Feeding trial lasted 6 wk under 16 h lighting regimen. The Exp. 2, was conducted with a total of 1,000 broilers chicks (Ross$^{(R)}$). They were divided into five treatments, same as those of Exp. 1. Birds were fed starter (0~3 wk) and grower (4~5 wk) diets. Each treatment was replicated four times with 50 birds per pen comprising of deep litter. In Exp. 1, egg production parameters, such as hen-day and hen-house egg production, egg weight, broken and soft shell egg production, feed intake and feed conversion were not significantly different among treatments. However, strength and thickness of eggshell were significantly (P<0.05) different. Among the probiotics, PB-Y showed the highest strength and thickness of eggshell. Eggshell color, egg yolk color and Haugh unit were not significantly influenced. In Exp. 2, overall weight gain (0~5 wk) and mortality were not significantly different among treatments. However, weight gain of birds from PB-Y treatment during starter (0~3 wk) was significantly lower than the birds from Control and Antibiotic treatment. During the whole period (0~5 wk), birds from Antibiotics treatment had higher feed intake and Production Index (PI) and lower feed conversion than birds from Control treatment. Probiotics treatments were not significantly different from the Control on feed intake and feed conversion. In Exp.1, there were significant (P<0.05) differences in leukocytes parameters, such as white blood cell (WBC), hetrophil (HE), lymphocytes (LY), monocyte (MO), eosinophil (EO) and stress index (SI; HE/LY) in the blood of layers. Birds from Antibiotics and probiotics treatments tended to increase these parameters. In Exp. 2, however, only SI was significantly (P<0.05) decreased in Antibiotics treatments. Concentration of serum immunoglobulin (IgG) were higher (P<0.05) in PB-M and PB-Y treatments when compared with Control treatment in Exp. 1. The population of E. coli significantly (P<0.05) decreased in birds from Antibiotics, PB-L and PB-Y treatments when compared with birds from Control treatment in Exp. 1. Metalbolizability of crude fat decreased significantly (P<0.05) in birds from probiotic treatments in Exp. 2. It was concluded that the response of probiotics on the productivity of layers and broilers were different. Probiotics increased strength and thickness of eggshell in layers, and decreased feed conversion and increased PI in broilers. Leukocytes and IgG tended to increase by supplementation of antibiotics and probiotics in layers. Intestinal E. coli tended to decrease in layers. Digestibility of crude fat of diet decreased in probiotics treatments broilers. Parameters of blood and microbial were more sensitive in layers than broilers.