• Title/Summary/Keyword: 전자관

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Characteristics of Soil Electrical Conductivity in Plastic Film House Located in Southern Part of Korea (남부지방(南部地方) 시설재배지(施設栽培地) 토양(土壤)의 염농도(鹽濃度) 특성(特性))

  • Ha, Ho-Sung;Lee, Yong-Bok;Sohn, Bo-Kyoon;Kang, Ui-Gum
    • Korean Journal of Soil Science and Fertilizer
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    • v.30 no.4
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    • pp.345-350
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    • 1997
  • Characteristics of electrical conductivity(EC) of seventy one-greenhouse soil located in southern part of Korea were surveyed to obtain the basic information for sustainable management of plastic film house soils. The averaged soil EC were 5.84 and 2.49dS/m for top-and sub-soil, respectively, showing distribution of 11.3% for top-soils and 50.7% for sub-soils within the optimum level of 2.0 dS/m. On the whole, the soils with flowering plants revealed higher EC than those with fruiting vegetables showing 2.75~6.34dS/m for the former and 2.29(sub-soils)~5.13dS/m(top-soils) for the latter. In a view of soil sampling time, the soils at Feb., 1996 marked 4.3~37.7% and 10.3(top-soils)~11.3%(sub-soils) higher EC compared with the soils at Sept. and Dec., 1995, respectively. The linear regression correlation coefficients of soil minerals to EC were in oder of $Mg^{2+}$ > $NO_3{^-}$ > $Cl^-$ > $Ca^{2+}$ > $SO_4{^{2-}}$ > $K^+$ for top-soils and were $Cl^-$ > $SO_4{^{2-}}$ > $NO_3{^-}$ > $Ca^{2+}$ > $Mg^{2+}$ > $K^+$ for sub-soils. In especial, the concentration of soil EC accompanied the increasing population ratio of soil fungi to bacteria and/or actinomycetes.

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Effect of Reperfusion after 20 min Ligation of the Left Coronary Artery in Open-chest Bovine Heart: An Ultrastructural Study (재관류가 허혈 심근세포의 미세구조에 미치는 영향 : 재관류 손상에 관한 연구)

  • 이종욱;조대윤;손동섭;양기민;라봉진;김호덕
    • Journal of Chest Surgery
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    • v.31 no.8
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    • pp.739-748
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    • 1998
  • Background: It has been well documented that transient occlusion of the coronary artery causes myocardial ischemia and finally cell death when ischemia is sustained for more than 20 minutes. Extensive studies have revealed that ischemic myocardium cannot recover without reperfusion by adequate restoration of blood flow, however, reperfusion can cause long-lasting cardiac dysfunction and aggravation of structural damage. The author therefore attempted to examine the effect of postischemic reperfusion on myocardial ultrastructure and to determine the rationales for recanalization therapy to salvage ischemic myocardium. Materials and methods: Young Holstein-Friesian cows(130∼140 Kg body weight; n=40) of both sexes, maintained with nutritionally balanced diet and under constant conditions, were used. The left anterior descending coronary artery(LAD) was occluded by ligation with 4-0 silk snare for 20 minutes and recanalized by release of the ligation under continuous intravenous drip anesthesia with sodium pentobarbital(0.15 mg/Kg/min). Drill biopsies of the risk area (antero-lateral wall) were performed at just on reperfusion(5 minutes), 1-, 2-, 3-, 6-, 12-hours after recanalization, and at 1-hour assist(only with mechanical respiration and fluid replacement) after 12-hour recanalization. The materials were subdivided into subepicardial and subendocardial tissues. Tissue samples were examined with a transmission electron microscope (Philips EM 300) at the accelerating voltage of 60 KeV. Results: After a 20-minute ligation of the LAD, myocytes showed slight to moderate degree of ultrastructural changes including subsarcolemmal bleb formation, loss of nuclear matrix, clumping of chromatin and margination, mitochondrial destruction, and contracture of sarcomeres. However, microvascular structures were relatively well preserved. After 1-hour reperfusion, nuclear and mitochondrial matrices reappeared and intravascular plugging by polymorphonuclear leukocytes or platelets was observed. However, nucleoli and intramitochondrial granules reappeared within 3 hours of reperfusion and a large number of myocytes were recovered progressively within 6 hours of reperfusion. Recovery was apparent in the subepicardial myocytes and there were no distinct changes in the ultrastructure except narrowed lumen of the microvessels in the later period of reperfusion. Conclusions: It is likely that the ischemic myocardium could not be salvaged without adequate restoration of coronary flow and that the microvasculature is more resistant to reversible period of ischemia than subendocardium and subepicardium. Therefore, thrombolysis and/or angioplasty may be a rational method of therapy for coronarogenic myocardial ischemia. However, it may take a relatively longer period of time to recover from ischemic insult and reperfusion injury should be considered.

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Effect of Blue Color-deficient Sunlight on the Productivity and Cold Tolerance of Crop Plants II. On the unsaturation of mitochondrial phospholipid (청색파장(靑色波長)영역이 결여된 태양광이 작물(作物)의 생산성(生産性) 및 내냉성(耐冷性)의 향상에 미치는 효과 II. 미토콘드리아막(膜)의 인지질불포화도(燐脂質不飽和度)의 증가)

  • Jung, Jin;Kim, Chang-Sook
    • Korean Journal of Environmental Agriculture
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    • v.5 no.2
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    • pp.149-155
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    • 1986
  • The fatty acid compositions of phospholipids extracted from leaves and leaf mitochondria, which were sampled from several horicultural plants grown under blue color-deficient sunlight (BCDS), were determined and compared with those from plants grown under natural white colored sunlight(WCS). It was found that the mitochondria isolated from plants grown under BCDS contained phospholipid whose degree of unsaturation in unit of number of double bonds per lipid molecule was remarkably higher than that from plants grown under WCS, the relative increment being $8{\sim}49%$. This was significantly larger than the relative increment, $4{\sim}8%$ for total phospholipid extracted from whole leaves grown under BCDS campared to WCS. This observation demonstrated that the blue light effect of sunlight on the chemical property of cellular membranes, as long as it was concerned with fatty acid composition, arose mainly at the mitochondrial membrane. Also observing that the degree of unsaturation of mitochondrial phospholipid was much lower than that of total phospholipid, it was interpreted that this was the consequence of rather active oxidative destruction of lipid-fatty acid components occuring in mitochondrial membrane by the reactive oxygen species, especially superoxide($O_2-$), which was known to be produced in mitochondrial inner membrane through the side reactions of the respiratory electron transport chain and also probably through the photosensitized reaction involving oxygen induced by blue colored light. Thus, it may be tentatively concluded that the extent of photosensitization in mitochondrial membrane could be considerably reduced under BCDS resulting in lowering of the $O_2-$ level in the respirating organelle The possible involvement of photodynamic action in membrane oxidation was also indicated by the fact that the typical fat-soluble antioxidant, ${\alpha}-tocopherol$, was found to be contained on a higher level in leaves under BCDS than those under WCS.

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Recent Developments in Law of International Electronic Information Transactions (국제전자정보거래(國際電子情報去來)에 관한 입법동향(立法動向))

  • Hur, Hai-Kwan
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.23
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    • pp.155-219
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    • 2004
  • This paper focuses on two recent legislative developments in electronic commerce: the "Uniform Computer Information Transactions Act" ("UCITA") of USA and the "preliminary draft convention on the use of data message in [international trade] [the context of international contracts]" ("preliminary draft Convention") of UNCITRAL. UCITA provides rules contracts for computer information transactions. UCITA supplies modified contract formation rules adapted to permit and to facilitate electronic contracting. UCITA also adjusts commonly recognized warranties as appropriate for computer information transactions; for example, to recognize the international context in connection with protection against infringement and misappropriation, and First Amendment considerations involved with informational content. Furthermore, UCITA adapts traditional rules as to what is acceptable performance to the context of computer information transactions, including providing rules for the protection of the parties concerning the electronic regulation of performance to clarify that the appropriate general rule is one of material breach with respect to cancellation (rather than so-called perfect tender). UCITA also supplies guidance in the case of certain specialized types of contracts, e.g., access contracts and for termination of contracts. While for the most part carrying over the familiar rules of Article 2 concerning breach when appropriate in the context of the tangible medium on which the information is fixed, but also adapting common law rules and rules from Article 2 on waiver, cure, assurance and anticipatory breach to the context of computer information transactions, UCITA provides a remedy structure somewhat modeled on that of Article 2 but adapted in significant respects to the different context of a computer information transaction. For example, UCITA contains very important limitations on the generally recognized common law right of self-help as applicable in the electronic context. The UNCITRAL's preliminary draft Convention applies to the use of data messages in connection with an existing or contemplated contract between parties whose places of business are in different States. Nothing in the Convention affects the application of any rule of law that may require the parties to disclose their identities, places of business or other information, or relieves a party from the legal consequences of making inaccurate or false statements in that regard. Likewise, nothing in the Convention requires a contract or any other communication, declaration, demand, notice or request that the parties are required to make or choose to make in connection with an existing or contemplated contract to be made or evidenced in any particular form. Under the Convention, a communication, declaration, demand, notice or request that the parties are required to make or choose to make in connection with an existing or contemplated contract, including an offer and the acceptance of an offer, is conveyed by means of data messages. Also, the Convention provides for use of automated information systems for contract formation: a contract formed by the interaction of an automated information system and a person, or by the interaction of automated information systems, shall not be denied on the sole ground that no person reviewed each of the individual actions carried out by such systems or the resulting agreement. Further, the Convention provides that, unless otherwise agreed by the parties, a contract concluded by a person that accesses an automated information system of another party has no legal effect and is not enforceable if the person made an error in a data message and (a) the automated information system did not provide the person with an opportunity to prevent or correct the error; (b) the person notifies the other party of the error as soon as practicable when the person making the error learns of it and indicates that he or she made an error in the data message; (c) The person takes reasonable steps, including steps that conform to the other party's instructions, to return the goods or services received, if any, as a result of the error or, if instructed to do so, to destroy such goods or services.

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Anticalcification Treatment of Glutaraldehyde-fixed Bovine Pericardium with Amino Acids (The Effect of Ethanol, Glutamic Acid and Homocysteic Acid Treatment) (글루타르알데하이드로 고정한 소 심낭의 아미노산을 이용한 항석회화 처리(에탄올, 글루타믹 산, 호모시스테익 산 처리의 효과))

  • Lee, Cheul;Kim, Yong-Jin;Lee, Chang-Ha;Kim, Soo-Hwan;Choi, Seung-Hwa
    • Journal of Chest Surgery
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    • v.42 no.4
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    • pp.409-417
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    • 2009
  • Background: Glutaraldehyde-fixed heterografts are prone to calcification after long-term implantation in human, and this is one of the limiting factors for the longevity of the heterografts used in cardiovascular surgery. The aim of the study was to evaluate the anticalcification effect of an ethanol and amino acids treatment on glutaraldehyde-fixed bovine pericardium. Material and Method: Bovine pericardial tissues were divided into 5 groups. Group 1 consisted of tissues fixed with glutaraldehyde, group 2 consisted of commercially available bovine pericardial valve tissues (Carpentier-Edwards PERIMOUNT), group 3 consisted of glutaraldehyde-fixed tissues treated with ethanol, group 4 consisted of glutaraldehyde-fixed tissues treated with ethanol and L-glutamic acid, and group 5 consisted of glutaraldehyde-fixed tissues treated with ethanol and homocysteic acid. The tissue microstructure was examined by light and electron microscopy. Tissue samples of each group were implanted into rat subcutaneous tissue for 3 $\sim$ 4 months and the calcium contents were measured after harvest. Result: The collagen fibers appeared to be well preserved in all the groups. The calcium contents of groups 2, 3, 4 and 5 (13.46$\pm$11.74, 0.33$\pm$0.02, 0.39$\pm$0.08 and 0.42$\pm$0.06 $\mu$g/mg, respectively) were all significantly lower than that of group 1 (149.97$\pm$28.25 $\mu$g/mg) (p<0.05). The calcium contents of groups 3, 4 and 5 were all significantly lower than that of group 2 (p<0.05). Conclusion: Treatment with ethanol alone or in combination with amino acids (L-glutamic acid or homocysteic acid) strongly prevented the calcification of glutaraldehyde-fixed bovine pericardium.

Elimination and Utilization of Pollutants - Part I Microbiological Clarification of Industrial Waste and Its Utilization as Feed Resources - (환경오염원(環境汚染源)의 제거(除去)와 그 이용성(利用性)에 관(關)한 연구(硏究) - 제(報I)1보(第). 미생물(微生物)에 의(依)한 산업폐수(産業廢水)의 정화(淨化) 및 사료자원개발(飼料資源開發)에 개(開)하여 -)

  • Lee, Ke-Ho;Lee, Kang-Heup;Park, Sung-O
    • Applied Biological Chemistry
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    • v.23 no.1
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    • pp.64-72
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    • 1980
  • Industrial wastes from pulp and food plants were treated with microorganisms to clarify organic waste-water and to produce cells as animal feed, and results were summarized as follows. (1) Waste-water from pulp, beer, bread yeast, and ethanol distillation plants contained $1.4{\sim}1.5%$ of total sugar, $0.25{\sim}0.35%$ nitrogen, and biological oxygen demand (BOD) was $400{\sim}25,000$, chemical oxygen demand (COD), $500{\sim}28,000$, and pH, $3.8{\sim}7.0$. The BOD and COD were highest in waste-water from ethanol distillation plants among others. (2) Bacterial and yeast counts were $4{\times}10^4-1{\times}10^9,\;2{\times}10^2-7{\times}10^4/ml$ in waste-water. (3) Bacteria grew better in pulp waste and yeasts in beer, bread yeast, and ethanol distillation waste. (4) Saccharomyces cerevisiae SAFM 1008 and Candida curvata SAFM 70 were the most suitable microorganisms for clarification of ethanol distillation waste. (5) When liquid and solid waste from ethanol distillation were treated with microbial cellulase, xylanase, and pectinase, solid waste was reduced by 36%, soluble waste was increased, and recuding sugar content was increased by 1.3 times which provided better medium than untreated waste for cultivation of yeasts. (6) Optimum growth conditions of the two species of yeast in ethanol distillation waste were pH 5.0, $30^{\circ}C$, and addition of 0.2% of urea, 0.1% of $KH_2PO_4$ and 0.02% of $MgSO_4$. (7) Minimum number of yeast for proper propagation was $1.8{\times}10^5/ml$. (8) C. curvata70 was better than cerevisae for the production of yeast cells from ethanol distillation waste treated with microbial enzymes. (9) S. cerevisiae produced 16 g of dried cell per 1,000ml of ethanol distillation waste and reduced BOD by 46%. C. curvata produced 17.6g of dried cell and reduced BOD by 52% at the same condition. (10) Yeast cells produced from the ethanol distillation waste contained 46-52% protein indicating suitability as a protein source for animal feed.

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Ultrastructure of Germ Cells, Cyst Epithelial Cells and Interstitial Cells during Spermatogenesis of the Stone Flounder, Kareius bicoloratus (돌가자미 Kareius bicoloratus의 정자형성과정 중 생식세포, Cyst 상피세포 및 간질세포의 미세구조)

  • Jun, Je-Cheon;Chung, Ee-Yung;Yang, Young Chul
    • Korean Journal of Ichthyology
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    • v.18 no.4
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    • pp.311-318
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    • 2006
  • Ultrastructure of germ cells, the cyst epithelial cells and interstitial cells during spermatogenesis of the stone flounder, Kareius bicoloratus (Pleuronectidae) sampled on the west coast of Korea were investigated by electron microscopic observations. In the primary spermatocyte, the synaptonemal complexes appear in the zygotene stage of the prophase during maturation division. In the growing testis, especially, the interstitial cells (Leydig cells) appear near the primary, secondary spermatocytes and spermatids. Well-developed interstitial cells (steroid hormone secreting cells) which are located in the interlobular space in growing testis have three morphological characteristics of a vesicular nucleus, mitochondria with tubular cristae and smooth endoplasmic reticulum. During spermatogenesis, the primary and secondary spermatocytes attach to the cyst epithelial cell (Sertoli cell) having an elongated ovoid or triangular nucleus and several mitochondria in the cytoplasm. In the growing testis, lipid droplets, the mitochondrial rosettes and glycogen particles appear in the cytoplasm of the cyst epithelial cells near the secondary spermatocytes and spermatids. Particularly, the mitochondria, endoplasmic reticulum, little lipid droplets and the large amount of glycogen particles are present in the cytoplasm of the cyst epithelial cell in the late growing testis. In the late stage of spermiogenesis, the proximal centriole is joined to the nuclear envelope, the distal centriole forms the basal body of the flagellum and gives rise to the axial filament of the flagellum. No acrosome of the sperm is formed as seen in other teleost fish. The head of the spermatozoon is approximately $3{\mu}m$ in length and its tail is about $30{\mu}m$ in length. The axoneme of the tail flagellum of the spermatozoon consists of nine outer doublet microtubules at the periphery and two centrial singlet microtubules at the center. The spermatozoon of this species has two axonemal lateral fins. Especially, the cyst epithelial cells which located near groups of gametes in the various stages, show three functions: nutrition, phagocytosis and steroidogenesis. Especially, the nuclei of cyst epithelial cells in the recovery stage of the testicular developmental stages appear to be irregular in shape after spermiation. Of three functions of the cyst epithelial cell, several characteristics of phagocytosis are showed in the cytoplasm of the cyst epithelial cells in the recovery stage of the testicular developmental stages. At this stage, therefore, it is assumed that the cyst epithelial cells are involved in degeneration and resorption of undischarged germ cells after spermiation.

The Analysis of the Trend of Research on Gastric Cancer Reported in Professional Journals in the Field of Surgery in Korea (국내 전문 학술지에 의한 위암 외과의 연구 경향에 대한 분석)

  • Oh, Cheong-Ah;Kim, Dae-Hoon;Oh, Seung-Jong;Cho, Hyun-Jin;Choi, Min-Gew;Noh, Jae-Hyung;Sohn, Tae-Sung;Bae, Jae-Moon;Kim, Sung
    • Journal of Gastric Cancer
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    • v.9 no.4
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    • pp.186-192
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    • 2009
  • Purpose: The aim of this study was to analyze the trend of the literature reported in the Journal of Korean Gastric Cancer Association (JKGCA) and the Journal of Korean Surgical Society (JKSS) in order to suggest new directions for the future studies on gastric cancer. Materials and Methods: The papers published in the Journal of Korean Gastric Cancer Association (JKGCA) and the Journal of Korean Surgical Society (JKSS) between 2001 and 2008 were compared and summarized in terms of the following categories, retrospective study, prospective study, case report, biomolecular study, genetic study, tumor marker study, review article, and report. Results: For recent 8 years, while the number of review articles in JKSS had initially increased, gradually fallen down and recently increased again, only a few (only 6 publications) in JKGCA have been published. The number of case reports in JKSS has gradually increased and fallen down. On the other hand, a few of case reports (1~3 publications) has been annually published in JKSS. Uniquely, reports were published only in JKGCA with the noticeable increase during the period from 2004 to 2005. For retrospective studies, in JKGCA the number started off very high and decreased, and finally increased again (U-shaped), whereas it had a bell-shaped trend in JKSS. The number of prospective studies in JKGCA had a bell-shaped trend, but the one in JKSS continued to decrease. Few papers of molecular biologic study, tumor marker study and genetic study had been published in both journals. Conclusion: We concluded that the transition from retrospective studies to prospective studies as well as a comprehensive multi-disciplinary team management of a clinical research would represent a desirable strategy in gastric cancer research.

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Effect of Freezing and Thawing Condition on the Physical Characteristics of Blanched Bean Sprouts as Home Meal Replacement (냉.해동 조건에 따른 간편편이식 콩나물의 물리적 품질 변화)

  • Jang, Min-Young;Jung, You-Kyoung;Min, Sang-Gi;Cho, Eun-Kyung;Lee, Mi-Yeon
    • Culinary science and hospitality research
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    • v.20 no.6
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    • pp.235-244
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    • 2014
  • The purpose of this study was to investigate the effect of freezing and thawing rate on the physical properties of soybean sprouts to improve the quality of processed soybean sprouts during distribution and storage. Cooked soybean sprouts were frozen by air-blast freezing (ABF) system at $-45^{\circ}C$ or natural air convection freezing (NCF) system at $-24^{\circ}C$, then thawed using microwave oven by varying output power (0, 400, 800 and 1,000 W) until $75^{\circ}C$. The quality of soybean sprouts was measured by the water content, hardness and springiness. In addition, the internal microstructure of soybean sprouts was observed by optical microscope. For results, water content of soybean sprouts thawed by 1,000 W in a microwave showed the lowest value after natural air convection freezing. Springiness of soybean sprouts thawed by all amounts of output power was decreased in comparison with control. Hardness was increased only in soybean sprouts thawed by 1,000 W after air-blast freezing. However the gaps between springiness and hardness were relatively small with control at 1,000 W thawing, after air-blast freezing. Internal microstructure of the soybean sprouts was more damaged as freezing and thawing time were increased. In conclusion, high freezing and thawing rate might improves the quality of soy bean sprout, and IQF freezing and 1,000 W of microwave thawing appears to be the optimum condition for frozen HMR production. From the results freezing and thawing process parameters might can be use as quality control parameters as various type of sprout products processing.

Effects of Feeding Induced Molting on the Performance, Egg Quality, and Visceral Organs in Laying Hens (산란계에서 급이환우가 산란계의 생산성과 계란의 품질 및 주요 장기에 미치는 영향)

  • Hong, E.C.;Na, J.C.;You, D.C.;Jang, B.G.;Kim, H.K.;Choi, Y.H.;Park, H.D.;HwangBo, J.
    • Korean Journal of Poultry Science
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    • v.34 no.3
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    • pp.197-205
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    • 2007
  • This study was conducted to compare the effect of feeding molting and fasting molting on the performance, egg quality, and visceral organs in laying hens for animal welfare. Eighty one 62-wk-old White Leghorn hens that egg production was over 80% and average weight was $1.6{\pm}0.3\;kg$ were used in this study. Treatments were control (non-molt treatment), feeding molt treatment, and fasting molt treatment. The three treatments were administered to three replicate group of nine hens wherein each group. All treatment groups were fed the basal diet (CP 15%, ME 2,700 kal/kg) for two weeks as the adaptation period. Induced molt diets contains low CP (6.7%) and low energy (2,200 kal/kg). Test periods were 14 days for feeding molting and 10 days for fasting molting. Egg production decreased to be 0% at 10 days of feeding molting treatment, but at 2 or 3 days of fasting molting treatment. Egg production restarted after 19 days ending molt at feeding molting treatment, while after 24 days at fasting molting treatment. On the egg quality was improved at molting treatments (p<0.05) except egg yolk. Egg shell tissue was crowded at molting treatment to compare to control. Liver weights, heart weight, and oviduct weight of laying hens decreased at molting treatments (p<0.05). Finally, feeding molting might could be replaced fasting molting on the welfare and further studies were needed about molting program.