• Proceedings of the Korea Society of Poultry Science Conference
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• 2000.11a
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• pp.88-90
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• 2000

Although primordial germ cells(PGCs) have been used in the production of germline chimera, efficiency has not been satisfactory. The Present study was conducted to improve efficiency of germline chimera production using the cultured gonadal PGCs(gPGCs). Germline chimeric chickens were produced by transfer of cultured gonadal primordial germ cells from Korean Ogol Chicken (KOC) to White Leghorn (5.5-day-old) and cultured in vitro for 10 days. Approximately 200 gPGCs (2-day-old) recipient embryos from which blood had been withdrawn via the dorsal aorta prior to the injection. Recipient embryos were incubated until hatching. Germline chimerism of the chickens reaching maturity was examined by mating them with Korean Ogol Chicken. Donor-derived offspring were identified as germline chimeric chickens based on their feather color. The frequency of germline transmission of donor PGCs ranged 1.9∼60.7%. There was no difference between both sexes. Therefore, it can be concluded that efficiency of germline chimerism can be improved via using cultured gPGCs.

• Korean Journal of Veterinary Research
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• v.15 no.2
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• pp.177-180
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• 1975

This study was undertaken to obtain more detailed knowledge of the oxygen consumption rate of chick embryos, of the relationship between the increasing rate of embryo weight and that of oxygen consumption, of the daily increase of oxygen consumption by that of embryo weight, and of the metabolic rate of the White Leghorn eggs. The results obtained are summarized as follows. 1. The average oxygen consumption rate of the chicken embryo at the 3rd day of incubation is 0.8ml/h, STPD. It is strongly suggested that this value can used as a physiological criterion to classify the fertilized and unfertilized eggs, on the other hand oxygen consumption rate of the fertilized eggs reaches a plateau between the 18th and 20th days. 2. There exists a parallel relationship between the increasing rate of embryo weight and that of oxygen consumption rate during the incubation period. 3. There are not exist a parallel relationship between the daily increase of embryo weight and that of oxygen consumption during the whole incubation period. 4. The metabolic rate of chicken embryo(ml/h/g) is highest in the early stage of incubation and it started to decrease sharply until the 8th day follow by slow decrease thereafter.

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.3
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• pp.306-312
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• 1986

Demonstration of the highly positive correlation between blood cholestrol levels and heart disease has made consumers wary of the fats in meat, milk and eggs. The egg, as perhaps the single largest common source of cholesterol, has been cited by many members of the medical and scientific world as a food contributing to heart disease. In light of decreasing per capita egg consumption and continuing dietary egg cholesterol controversy, many researchers have focused their efforts on egg nutrition. The results reported, however, are often contradictory. In spite of the disputable scientific evidence, the egg has been labelled (erroneously) as a highly cholesterogenic food. The objective of this presentation is to present a general picture of the problem and discuss our laboratory findings relevant to the problem. An isotope technique was utilized to incorporate $^{14}C$-cholesterol into egg yolk lipoproteins and study the metabolic fate of dietary ovo-cholesterol in rats. Two hundred and fifty micro-curies of 4-$^{14}C$-cholesterol, emulsified in corn oil, were orally administered to five Single Comb White Leghorn laying hens. Eggs were collected, hard-boiled, and the hot dried egg yolk powder (HEY) was prepared. Total radioactivity excreted via feces was determined. The rat groups fed egg yolk powder excreted more than 95% of the ingested ovo-cholesterol, whereas the rat chow group excreted only 47%. No difference was observed between HEY and CEY treatments. Therefore, an unknown lipid factor present in egg folk accelerates cholesterol turnover rate and excretion via feces.

• YAKHAK HOEJI
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• v.49 no.1
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• pp.6-10
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• 2005

Immunoglobulin Y (IgY) obtained from chicken as the immunization host brings several advantages to antibody production, such as improved yield, lower cost, longer stability and higher specificity than mammalian immunoglobulin. In the present study, we attempted to produce IgY against a sialic acid-binding lectin, Maackia fauriei agglutinin (MFA), from egg yolk of white Leghorn hens. For the isolation of IgY from egg yolk, we applied a water dilution method. The weekly yield of IgY was determined by enzyme-linked immunosorbent assay, with a final yield of anti-MFA IgY from total IgY of approximately $1\%$. The yielded IgY were used to prepare IgY-affinity column conjugated with CNBr-activated Sepharose 4B, which resulted in the lectin being successfully purified in a single step from Maackia fauriei. This purified lectin exhibited the same hemagglutination activity as lectin purified using conventional purification methods.

• Journal of Animal Science and Technology
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• v.52 no.6
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• pp.491-498
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• 2010

Copy-number variation (CNV) in particular genomic segments owing to deletions or duplications can induce changes in cellular gene expression patterns and may increase susceptibility to diseases such as cancer. The aim of this study was to examine CNVs related to the incidence of epithelial ovarian cancer in chickens. Genomic DNA was extracted from blood cells and cancerous ovaries collected from four 120-week-old White Leghorn chickens and were used for array-based comparative genome hybridization (CGH) analysis. As a result, 25 amplified and 10 deleted CNV regions were detected in chicken ovarian cancer. Of these, 10 amplified and two deleted CNV regions contained genes associated with human ovarian cancer. Our study using a chicken model may provide a better understanding of human epithelial ovarian cancer.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.20-20
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• 2003

Phenotypic characteristics and genetic markers in livestock have been utilized for improvement of the economic traits including egg productivity. Korean Native Ogol Chicken (KNOC) has low egg productivity compared to White Leghorn. Therefore, in this study, serum IGF-I concentration and number of egg production were used as selection markers to improve egg productivity. KNOCs were divided into three groups showing high IGF-I concentration (IGF-I high), high egg production (EP high), and IGF-I/EP high groups. Blood was collected every 10 weeks, and serum concentrations of IGF-I, estradiol (E2), and progesterone (P4) were measured by radioimmunoassay. In comparison of three groups in each generation, the highest increment of egg production was detected in the IGF-I/EP high group from 20 weeks till 40 weeks, and the IGF-I high group also showed the significant increment of egg production after 50 weeks. Interestingly, there were the increase of egg production and decrease of periods in sexual maturity in the second and third generation selected by serum IGF-I concentration, while egg weight and body weight decreased during experimental period. In conclusion, the present study suggest the possibility of IGF-I as a selection marker to improve the egg productivity of KNOC.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.10
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• pp.1359-1365
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• 2009

We performed a genome-wide linkage and quantitative trait locus (QTL) analysis to confirm the existence of QTL affecting Rous Sarcoma Virus (RSV) induced tumor regression, and to estimate their effects on phenotypic variance in an F2 resource population. The F2 population comprised 158 chickens obtained by crossing tumor regressive White Leghorn (WL) and tumor progressive Rhode Island Red (RIR) lines was measured for tumor formation after RSV inoculation. Forty-three tumor progressive and 28 tumor regressive chickens were then used for genome-wide linkage and QTL analysis using a total of 186 microsatellite markers. Microsatellite markers were mapped on 20 autosomal chromosomes. A significant QTL was detected with marker LEI0258 located within the MHC B region on chromosome 16. This QTL had the highest F ratio (9.8) and accounted for 20.1% of the phenotypic variation. Suggestive QTL were also detected on chromosomes 4, 7 and 10. The QTL on chromosome 4 were detected at the 1% chromosome-wide level explaining 17.5% of the phenotypic variation, and the QTLs on chromosome 7 and 10 were detected at the 5% chromosome-wide level and explained 11.1% and 10.5% of the phenotypic variation, respectively. These results indicate that the QTLs in the non-MHC regions play a significant role in RSV-induced tumor regression. The present study constitutes one of the first preliminary reports in domestic chickens for QTLs affecting RSV-induced tumor regression outside the MHC region.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.3
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• pp.433-440
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• 1993

Means and standard errors of 285 Taiwan's local chicken and 429 Single Comb White Leghorn pullets at 35 wk of age were: egg weight (g) $48.3{\pm}0.3$, $54.6{\pm}0.3$, shell index $73.39{\pm}0.26$, $73.20{\pm}0.18$, shell color $15.23{\pm}0.40$, $0.88{\pm}0.27$, shell whiteness $72.61{\pm}0.57$, $90.00{\pm}0.35$, shell strength ($kg/cm^2$) $3.77{\pm}0.07$, $3.35{\pm}0.05$, shell thickness (mm) $0.38{\pm}0.003$, $0.38{\pm}0.002$, Haugh units $85.26{\pm}0.50$, $91.81{\pm}0.38$ and yolk percent (%) $30.17{\pm}0.18$, $27.32{\pm}0.16$ respectively. Theestimated heritabiliities of Taiwan's local chicken based on sire and dam components of variance were as follows: egg weight 0.20, shell index 0.1, shell color 0.87, shell whiteness 0.79, shell strength 0.37, shell thickness 0.14, Haugh units 0.24 and yolk percent 0.16. Genetic correlations based on sire and dam components of variance and covariance were also estimated. Generically, the shell index was positively correlated with egg weight, shell strength and yolk percent, and egg weight was negatively correlated with shell thickness, Haugh unit and yolk percent.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.11
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• pp.1565-1571
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• 2003

Physiological mechanisms, involved in unusual ovulatory sequences in domestic hen are remaining undefined. One hundred individually caged white leghorn birds were divided into two equal groups viz. control and treatment, and 2-bromo-$\alpha$-ergocryptine, was administered to birds in the treatment group to modulate prolactin (PRL) secretion from anterior pituitary gland. The effect of modulation of PRL concentrations on egg production, sequence length and intersequence pause length were studied by analysis of oviposition records of the birds from 24 to 72 weeks of age. The surviving 48 birds in the control and treatment groups averaged $34.58{\pm}1.7$ and $25.67{\pm}1.15$ sequences of oviposition, with a mean sequence length of $9.92{\pm}0.63$ and ${\pm}1.12$ days respectively. Most of the birds had a single characteristically long sequence during the entire reproductive cycle, which averaged $46.04{\pm}3.09$ days in the control birds and $59.33{\pm}4.44$ days in the treated birds. 2-bromo-$\alpha$-ergocriptine treatments had significantly decreased (p$\leq$0.01) the circulating concentrations of PRL compared to the birds of the control group. This resulted in a significant increase (p$\leq$0.01) in the number of laying days in birds of the treatment group with a concomitant decrease in the intersequence pause length. The decreased PRL levels during prime sequences in birds of the both groups, reveals the negative role of the circulating PRL levels on egg production with concomitant shorter intersequence pause length. Hence, modulation of PRL with dopamine agonist may enhance the reproductive efficiency of hens later in life.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.10
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• pp.1487-1494
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• 2003

Studies were conducted with intact White Leghorn roosters to determine the true metabolisable energy (TME) and the true amino acid availability (TAAA) in five dehulled and hulled soybean meals produced in China. 60 roosters, kept in individual cages, were fasted for 48 h and then tube-fed 50 g of one of experimental feedstuffs and their excreta was then collected for the subsequent 48 h period. Two separate collection periods were used with each meal being fed to 12 roosters. The birds were given a 15-day recovery period between collection periods. An additional 12 roosters were either fasted or fed a protein-free diet in order to estimate the extent of endogenous losses of energy and amino acids in excreta. The average values per bird for nitrogen loss, endogenous energy losses (EEL) and endogenous energy losses corrected to zero-nitrogen balance ($EEL_n$) were found to be 0.74 g, 47.0 kJ and 21.5 kJ, respectively. It was found that the TME and TAAA values of dehulled soybean meal were higher than those of hulled soybean meal. The TME and nitrogen-corrected TME metabolisable energy values of dehulled soybean meal were 10.58 and 10.74 MJ/kg, respectively, while the corresponding values for hulled soybean meal were 10.03 and 10.27 MJ/kg, respectively. The average indispensable and dispensable amino acid availability of dehulled soybean meal was 92.1 and 93.5%, compared with 89.3 and 91.4% for hulled soybean meal. Dehulled soybean meal would therefore appear to be superior to hulled soybean meal as a source of protein and energy for use in poultry rations.