• Asian-Australasian Journal of Animal Sciences
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• v.23 no.3
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• pp.292-301
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• 2010

Follicle-stimulating hormone (FSH) is a pituitary glycoprotein hormone that is encoded by separate alpha- and betasubunit genes. It plays a key role in stimulating and regulating ovarian follicular development and egg production in chicken. FSH signal transduction is mediated by the FSH receptor (FSHR) that exclusively interacts with the beta-subunit of FSH, but characterization of prokaryotic expression of the FSHb gene and its effect on the expression of the FSHR gene in local chickens have received very little attention. In the current study, the cDNA fragment of the FSHb gene from Dagu chicken was amplified using reverse transcription polymerase chain reaction (RT-PCR), and inserted into the pET-28a (+) vector to construct the pET-28a-FSHb plasmid. After expression of the plasmid in E. coli BL21 (DE3) under inducing conditions, the recombination protein, $FSH{\beta}$ subunit, was purified and injected into the experimental hens and the effect on the mRNA expression levels of the FSHR gene was investigated. Sequence comparison showed that the coding region of the FSHb gene in the local chicken shared 99%-100% homology to published nucleotides in chickens; only one synonymous nucleotide substitution was detected in the region. The encoded amino acids were completely identical with the reported sequence, which confirmed that the sequences of the chicken FSHb gene and the peptides of the $FSH{\beta}$ subunit are highly conserved. This may be due to the critical role of the normal function of the FSHb gene in hormonal specificity and regulation of reproduction. The results of gene expression revealed that a recombinant protein with a molecular weight of about 19 kDa was efficiently expressed and it was identified by Western blotting analysis. After administration of the purified $FSH{\beta}$ protein, significantly higher expression levels were demonstrated in uterus, ovary and oviduct samples (p<0.05). These observations suggested that the expressed $FSH{\beta}$ protein possesses biological activity, and has a potential role in regulation of reproductive physiology in chickens.

• Journal of Animal Science and Technology
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• v.54 no.2
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• pp.125-131
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• 2012

The study was conducted to investigate the effects of dietary supplementation of Macsumsuk and herb resources on the egg performance and quality in Korean native crossbred chickens. A total of three hundred sixty improved Korean native crossbred chickens in primary laying period were randomly allocated to four treatments (30 birds/treatment ${\times}$ 3 replications) for eight weeks. Dietary treatments included CON (basal diets), T1 (basal diets + 0.3% Macsumsuk), T2 (basal diets + 0.3% herb resources) and T3 (basal diets + 0.3% Macsumsuk + 0.3% herb resources). No significant differences were found for feed intake, egg weight and average egg production (P>0.05), however, cracked egg rate was higher in CON than in T1-T3, especially T3 was the lowest (P<0.05). The crude fat content of whole eggs, CON (11.20%) was higher (P<0.05) than the experimental treatments (9.67%-10.01%). Haugh unit, yolk color, eggshell thickness, and eggshell breaking strength tended to be higher in T1 and T2, but there were no significant differences (P>0.05). However, the experimental treatments were significantly higher than CON (P<0.05) for eggshell breaking strength, and T3 (14.91 mg/g) contained lower (P<0.05) cholesterol in egg yolk than other treatments. For fatty acid composition in egg yolk, CON group showed higher saturated fatty acid contents than the experimental treatments, but T1 (67.00%), T2 (66.78%) and T3 (66.82%) were higher than CON for unsaturated fatty acids (P<0.05). In conclusion, supplementating Macsumsuk and herb resources together in diets of Korean native crossbred chickens could decrease egg yolk cholesterol and improve egg quality.

• Korean Journal of Poultry Science
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• v.41 no.2
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• pp.99-104
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• 2014

The objective of this study is to analyze the production of extra-large egg and assess the impacts of exogenous factors in feeding the layer chicken. The main results of this study are as follows; First, feeding rations on the basics of statistics, internal maximum and minimum temperature and, the age at first egg affect the production of extra-large egg. Second, implicating the standardized coefficients from the conclusion of regression model estimating suggest that the amount of feed has the greatest impact on production followed by the age at first egg. Third, by using the elasticity of output and the volatility in the production, the result suggest that among the independent variable factors in the external volatility, the biggest one goes to feed ration, and the age at first egg follows. In order to control the production volatility in the extra-large egg production of the farms, it is necessary to manage an efficient feeding based on feed ration, age at first egg and, the maximum and minimum temperature inside the farm. Taken together, the results demonstrates that it should be concentrated by controlling the exogenous factors affecting extra large egg production and the management system construct, to increase extra-large egg production and the income of farmers at the same time.

• Korean Journal of Poultry Science
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• v.32 no.4
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• pp.231-237
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• 2005

This study was carried out to evaluate the breeding values for economic traits in Korean native chicken on the basis of 11,583 birds of record along 7 generations collected from 1995 to 2001 at National Livestock Research Institute, Korea. The results obtained are summarized as follows : The breeding value estimates of the body weights at 150 and 270 days in Dark Brown, Light Brown, Gray Brown, Black and White strains were $-16.563\~0.474\;and\;-18.836\~21.700,\;-14.714\~9.272\;and\;-23.025\~11.297,\; -25.186\~12.953\;and\;-28.368\~18.156,\;-15.549\~6.329\;and\;-18.264\~4.963,\;-10.708\~20.284\; and\;-25.112\~10.132g$, respectively. The breeding value estimates of the ages at first egg in Dark Brown, Light Brown, Gray Brown, Black and White strains were $-1.236\~0.047,\;-1.509\~0.298,\;-1.362\~0.114,\;-1.436\~0.199\;and\;-1.385\~0.718$, respectively. The breeding value estimates of the egg weight at first egg and at 270 days were $-0.105\~0.075\;and\;-0.120\~0.398,\;-0.109\~0.042\;and\;-0.205\~0.173,\;-0.166\~0.084\;and\;-0.256\~0.091,\;-0.119\~0.066\;and\;-0.051\~0.132,\;-0.112\~0.027\;and\;-0.070\~0.101g$, respectively. The breeding value estimates of the egg Production to 270 days in Dark Brown, Light Brown, Gray Brown, Black and White strains were $0.298\~l.807,\;-0.049\~l.146,\;-0.396\~l.125,\;-1.206\~l.173\;and\;-0.474\~2.641$, respectively.

• Korean journal of food and cookery science
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• v.30 no.1
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• pp.64-75
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• 2014

Freeze-drying process was used for 10 major protein foods referred by the Korea Health Statistics 2011 as follows; chicken, pork, beef, eggs, tofu, squid, soybean, mackerel, anchovy, and pollack/frozen pollack. Boiled samples and re-hydrated samples after freeze-drying were prepared for analysis. The weight variation, the chromaticity, the mechanical texture and sensory properties by eight trained panelists were measured. In the ratio of re-hydration, the anchovy showed the highest value(89.40%), followed by eggs, and squid showed the lowest value(35.51%). Changes of Hunter color value were observed among all samples. For rates on changes of hardness, every sample was increased except for eggs(p<.05). Among the 9 samples, except for eggs, chicken showed the lowest rate of increase in hardness(125.44%) while squid showed the highest rate of increase in hardness(1335.1%). Except for eggs and pork, eight samples represented differences in sensory properties, especially in juiciness and tenderness(p<.05). As a result, we found that egg is the most suitable for freeze-drying among 10 protein sources followed by pork and chicken.

• 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.

• Parasites, Hosts and Diseases
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• v.48 no.1
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• pp.49-55
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• 2010

In vitro cultivation of trematodes would assist studies on the basic biology of the parasites and their hosts. This is the first study to use the yolk of unfertilized chicken eggs as a simple and successful method of ovocultivation and the first time to obtain the adult-stage of the trematode Cymatocarpus solearis Braun, 1899 (Digenea: Brachycoeliidae). Chicken eggs were inoculated with metacercariae from the muscle of the spiny lobster, Panulirus argus (Latreille, 1804). The metacercariae were excysted and incubated for 576 hr (24 days) at $38^{\circ}C$ to obtain the adult stage. Eggs in utero were normal in shape and light brown color. The metacercariae developed into mature parasites that have been identified as the adultstage found in marine turtles. The adult lobsters collected in Quintana Roo State, Mexico, showed the prevalence of 49.4% and the mean intensity of 26.0 per host (n=87). A statistical study was performed to determine that no parasitic preference was detected for male versus female parasitized lobsters. Morphometric measurements of the adult-stage of C. solearis obtained in our study have been deposited in the National Helminths Collection of the Institute of Biology of the National Autonomous University of Mexico. This study is significant because it is the first time that a digenean of the family Brachycoeliidae has been demonstrated to develop in vitro from metacercariae into adults capable of producing eggs using the yolk of unfertilized chicken eggs. Secondly, this technique allows to obtain the adult stage of C. solearis without the presence of its marine turtle host, allows us to describe the mature parasites, and thus contribute to our understanding of the biology of C. solearis.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.7
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• pp.937-942
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• 2009

The aim of this study was to analyze the effects on growth and muscle development during the growing period of the sex-linked dwarf gene in the background of a Taiwan Country chicken strain, L2, selected for egg production. Eight crossbred males, heterozygous for the DW*DW mutation, were each backcrossed to six females of the L2 strain to produce two genotypes of BC females, either normal (DW*N+/-) or dwarf (DW*DW/-). The experiment included 251 normal and 207 dwarf pullets. The effect of the dwarf gene on body weight and shank length was highly significant from 2 weeks of age. The reduction of body weight by the dwarf gene reached 34.8% and 37.4% as compared to normal sibs at 16 and 20 weeks of age, respectively. Parameters of the growth curve were estimated: the age at inflection (TI) was higher in normal pullets (66.9 days) than in dwarf pullets (61.2 days). A significant effect of the dwarf gene on single muscle fiber cross-section area was found from 12 weeks of age onwards, whereas the dwarf gene had no effect on the total number of muscle fibers. Comparing the effect of the dwarf gene on shank length at different ages revealed an earlier effect on skeleton growth, observed from 2 weeks of age, than on muscle development, which was affected from 8 to 12 weeks of age.

• Journal of the Korean Dietetic Association
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• v.24 no.4
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• pp.330-343
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• 2018

Recently, there has been a growing demand for natural preservatives because of increased consumer interest in health. In this study, we produced Lactobacillus rhamnosus cell-free supernatant (LCFS) and evaluated and compared its antimicrobial activity with existing natural preservatives against pathogenic microorganisms and in chicken breast meat contaminated with Escherichia coli and Staphylococcus aureus. Lactobacillus rhamnosus cell-free supernatant possessed 30 units of lysozyme activity and contained 18,835 mg/L of lactic acid, 2,051 mg/L of citric acid and 5,060 mg/L of acetic acid. Additionally, LCFS inhibited the growth of fourteen pathogenic bacteria, S. aureus, Bacillus cereus, Listeria monocytogenes, Vibrio parahaemolyticus, Listeria innocua, S. epidermidis, L. ivanovii, E. coli, Pseudomonas aeruginosa, Shigella sonnei, Shi. flexneri, Proteus vulgaris, Pseudomonas fluorescens, and Klebsiella pneumoniae. The antibacterial activity of LCFS was stronger than that of egg white lysozyme (EWL), Durafresh (DF) and grapefruit seed extract (GSE). Additionally, LCFS maintained its antimicrobial activity after heat treatment at $50^{\circ}C{\sim}95^{\circ}C$ and at pH values of 3~9. Moreover, LCFS inhibited the growth of E. coli and S. aureus in chicken breast meat. In conclusion, it is expected that LCFS, which contains both lysozyme and three organic acids, will be useful as a good natural preservative in the food industry.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.4
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• pp.579-584
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• 2009

In this experiment, three different diets were produced to investigate the effects of Jeju native chicken eggs fed with citrus peel on the profiles of rats. The first diet did not contain any eggs (TS), the second diet contained 10% eggs and no citrus peels (T0), and the third diet contained 10% chicken egg with citrus peels (T1). These diets were provided to 11-week-old male rats for four weeks. The weight gain, feed intake and feed efficiency were not significantly different between the three treatment groups, TS, T0, and T1. The weight of the liver was significantly higher in T0 and T1 than TS (p<0.05), but the weights of the kidney and epididymal fat pad were not significantly different between the TS, T0, and T1 groups. The total lipid, phospholipid, triglycerides, total cholesterol and LDL cholesterol did not significantly difference among the TS, T0, and T1 groups. The HDL cholesterol and HDL cholesterol/ total cholesterol of T1 were the highest among the groups, and the atherogenic index of T1 was the lowest among the groups (p<0.05). The total protein of TS was significantly lower in T0 and T1, and the albumin of T1 was the highest among the groups (p<0.05). The albumin/globulin ratio of TS was significantly higher in T0 and T1, but the creatinine of T0 was significantly higher in T0 and T1 (p<0.05). The blood sugar and blood pigment were not significantly different between the TS, T0, and T1 groups. The $\gamma$-GTP of T1 was the lowest among the groups (p<0.05), but the ALT, AST and ALP did not show significant difference among the TS, T0, and T1 groups.