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        검색결과 24

        1.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Data on the crude protein requirements of elk doe are nonexistent and the data are essential for their management in Korea. Therefore, this study was conducted to evaluate the crude protein requirement for maintenance of elk doe. Three female elk deer were used in 3 × 3 Latin square design with three diets containing three levels of crude protein (CP) that contained low crude protein (approximately 12%), medium crude protein (15%), and high crude protein (18%). Each three elk doe trials included a 14-day preliminary period and a 5-day collection period. Crude protein intake was 4.83, 6.26, and 9.00 g/d for 12%, 15%, and 18% of CP level, respectively. Crude protein balances were 1.04, 1.41, and 4.14 for 12%, 15%, and 18% of CP level, respectively. The maintenance requirement for CP from the regression equation between CP intake and CP balance were 3.70 g/BW0.75.
        4,000원
        2.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The normal feeding approach of goats might be due to their precise anatomical and physiological characteristics of entity, which permit them to be highly selective, to eat legume silages and wild green grass. This review has been designed to consider the grazing behavior, fodder selection, and feed composition of goats. Various herbs and corns consumed by goats have numerous nutritive resources. Based on the general herbaceous intake activities and behavior of goats, they prefer wild grass such as grass grown in the steep hills than soft grass. Because the digestion capacity of cellulose feed has higher digestion level compared to other non-ruminants within rumen and it is advantageous to use wild forest or mountain grass which comprises high proportion of cellulose feed for goat. In South Korea, there are abundant feed resources for goats because of occupying large areas of mountains. Thus, goat production and feeding costs could be reduced if plants are used from the wild forest as a feed for goats relative to grassland grazing. Also, it is expected to contribute in improvement of goat farming with harmonious relationship between the grassland and wild forest while satisfying animal welfare and physiological desires of livestock.
        4,000원
        3.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to predict the energy requirements for maintenance and growth of female Korean black goats during their growth and pregnancy phases. Fifty female goats (18.7±0.27 kg) in their growth phase with an average age of 5 months were stratified by weight and randomly assigned into 5 groups. They were fed 5 diets varying in metabolic energy (ME) [2.32 (G1), 2.49 (G2), 2.74 (G3), 2.99 (G4), and 3.24 (G5) Mcal/kg] until they were 9-month-old. After natural breeding, 50 female goats (30.7±0.59 kg) were stratified by weight and randomly assigned into 5 groups. They were fed 5 diets varying in ME [2.32 (P1), 2.43 (P2), 2.55 (P3), 2.66 (P4), and 2.78 (P5) Mcal/kg]. The average feed intake ranged between 1.5 and 2.0% of the body weight (BW), and there was no significant difference between the treatment groups with goats in growth or pregnancy phases. Average daily gain (ADG) in diet demand during the growth phase increased with an increasing ME density and ranged from 46 to 69 g/d (p<0.01). Feed conversion ratio (FCR) improved with the ME density during the growth phase (p<0.01). The intercept of the regression equation between ME intake and ADG indicated that energy requirement for maintenance of goats during growth and pregnancy phases was 103.53 kcal/BW0.75 and 102.7 kcal/BW0.75, respectively. These results may serve as a basis for the establishment of goat feeding standards in Korea. Further studies are required to assess the nutrient requirement of goats using various methods for improving accuracy.
        4,000원
        4.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        TMR 급여와 분리급여가 반추위 메탄발생량 변화에 미치는 효과를 연구한 사례가 많지 않다. 본 실험은 1일 실험사료를 체중의 1.8%(실험 1) 그리고 2.4%(실험 2) 수준에서 급여 하면서 triplicated 2×2 Latin square design을 이용하여 실험을 수행하였다. 각 실험에는 6마리의 Holstein steer를 이용하였고 2개의 군으로 나누어 각각 TMR 급여 또는 분리급여를 하였다. 공시 사료의 농후사료와 조사료 비율은 73% 그리고 27%이었다. 두 실험 모두 사료급여 방식 간의 1일 메탄발생량 차이가 없었다. 현재까지 보고된 국내 연구와 본 연구에서 얻어진 개체 별 1일 건물섭취량과 1일 메탄발생량과의 관계를 분석한 결과, 메탄발생량 (g/d) = 11.5 (±1.3) × 건물섭취량 (kg/d) + 14.2, R2 = 0.73, p<0.001의 회귀식을 유도하였다.
        4,000원
        5.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present experiment was designed to investigate the effects of extruded linseed supplementation on methane production in Holstein steers. Four Holstein steers fitted with permanent cannulas were assigned to two dietary treatments in a duplicated 2 × 2 Latin square design: a control diet consisting of tall fescue straw (65%) and concentrate (35%), and a treatment diet supplemented with 3.8% extruded linseed by replacing a part of ingredients in the concentrate of the control diet. The concentrates of the control and the treatment diet were isoenergetic and isonitrogenous. Extruded linseed supplementation did not affect dry matter intake but significantly (P<0.05) increased the intake of lipid. Rumen pH was significantly (P<0.05) lower for control than for treatment. Although there was no significant difference between treatments, the concentration of total VFA in control was 21% higher than in treatment. The concentrations of acetic acid, propionic acid and butyric acid were not different between treatments. Extruded linseed supplementation significantly (P<0.05) reduced methane output(g/d) and emission factor. Methane conversion rate was lower for treatment than for control but no significant difference was found. The results of the present study showed that extruded linseed supplementation in the diet of Holstein steers could reduce methane output.
        4,000원
        6.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted with two ruminally cannulated Holstein steers to examine the effect of micronized and steam flaked corn on ruminal fermentation characteristics. The in situ dry matter degradability after 48 h incubation was the highest (P<0.05) at micronized corn (2.5 mm thickness) compared with steam flaked corn treatments. The steam flacked corn (3.3 mm thickness) was degraded lower (P<0.05) than the 2.9 and 3.1 mm thickness of steam flacked corn. Effective dry matter degradability and the rate of constant were the highest (P<0.05) at micronized corn (2.5 mm thickness) compared with steam flaked corns as well. The in vitro dry matter degradability after 48 h incubation was tended to higher (P=0.088) at micronized corn (2.5 mm thickness) than steam flaked corns, whereas there is no significantly difference between steam flaked corn treatments. Total volatile fatty acid concentration was higher at steam flaked corn (2.9 mm thickness) than micronized corn (2.5 mm thickness) and steam flaked corn (3.1 and 3.3 mm thickness). The acetate : propionate ratio was the highest (P=0.008) at steam flaked corn (2.9 mm thickness) and the lowest (P=0.008) at micronized corn (2.5 mm thickness). Total gas and methane production after 48h ruminal incubation was the highest (P=0.001) at micronized corn (2.5 mm thickness) compared with steam flaked corns. According to these results, the thickness of steam flaked corn as resulted corn processing is believed to do not affect methane production. However, further study is needed to better understand the present results to verify the correlation between corn processing method and their thickness on methane production using the same thickness corns by difference processing methods.
        4,000원
        7.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 국내 주요 조사료(rice straw, timothy and alfalfa) 및 쑥과 녹차의 반추위 소화율과 물리 적 구조를 비교하기 위해 in vitro 와 in situ 실험을 실시하였다. 각 사료별 3, 6, 9, 12, 18, 24, 36, 48 및 72 시간 동안 배양하였고, in vitro 실험에서는 가스 발생량, 미생물 성장량, pH를 측정하였다. 가스발생량은 배양시간이 경과할 수록 모든 시간대에서 증가하였고(p<0.05), 녹차에서의 가스발생량이 가장 낮았다. 미생물 성장량은 배양시간이 경과할수록 모든 처리구에서 증가하는 경향이었으나, 유의차 는 나타나지 않았고(p<0.05), 쑥과 녹차의 미생물 성장량이 다른 처리구에 비해 낮게 나타났다 (p<0.05). 반추위내 pH는 배양시간 경과할 수록 감소하였고, 티모시의 pH가 다른 사료에 비해 가장 낮 았으며, 볏짚의 pH가 다른 사료에 비해 높았다(p<0.05). In situ 실험에서 모든 시간대 녹차의 건물소 화율(DM; Dry Matter) 및 조단백 소화율(CP; Crude Protein)은 가장 높았다(p<0.05). 또한 반추위내 통과 속도 4% 쑥에서 건물소화율이 가장 높았고, 알팔파는 조단백 소화율이 가장 높았다(p<0.05). 녹차 와 쑥의 표면과 기공을 주사전자현미경(SEM; scanning electron microscope)으로 관찰한 결과, 쑥 표 면에는 미생물이 존재하지 않아 반추위 내 영양소 소화율이 낮은 것으로 사료되고, 녹차는 기공에 미생 물이 관찰 되었다. In vitro 및 in situ 실험의 결과를 통하여 반추동물의 사료원료로 잠재적인 가치가 있을 것으로 사료된다.
        4,600원
        10.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the effects of antiprotozoal plant extracts on in vitro ruminal fermentation and methane emission. Ruminal contents were collected from two ruminally-fistulated steers (Average BW: 450±30 kg) consuming 60% Timothy hay and 40% concentrate with free access to water and mineral block. Plant extracts, Lonicera japonica, Torreya nucifera, Zanthoxylum schinifolium, Poncirus trifoliate and Citrus junos, which have been known to have antiprotozoal and antiparasitic effects were added (5% of substrate) to the in vitro ruminal fermentation bottles containing the mixture of rumen fluid and McDougall’s buffer. The McDougall buffer (1000 ml) and ruminal inoculums (500 ml) were combined and 20 ml added to the 50 ml fermentation vessels containing 300 mg of substrate (DM basis). The fermentation vessels were placed in an incubator at 39°C for 3, 6, 9, 12, 24, 48 and 72 h with shaking. Plant extracts addition was decreased (p<0.05) acetate:propionate compared with control except with T. nucifera addition. Total gas production was increased (p<0.05), whereas methane emission was decreased (p<0.05) by all plant extracts compared with control at 12 h incubation. Methane emission at 24 h incubation was decreased for Lonicera japonica, Torreya nucifera, and Zanthoxylum schinifolium compared with control as well. In addition, methanogenic archaea was decreased (p<0.05) by all plant extracts at the 12 h incubation. These results indicate that the plant extracts may decrease methane emission by inhibiting methanogenesis without the decrease of total gas production in 12 h in vitro ruminal fermentation. Therefore, plant extracts which have the antiprotozoal effect may be promising feed additives for ruminants as a methane inhibitor
        4,500원
        11.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Mesenchymal stem cells (MSCs) are multipotent stem cells, which can be induced to differentiate into several cells. MSCs are also reported to possess immunomodulatory properties through secretion of inflammatory cytokines and generation of regulatory T (Treg) cells. Treg cells play an important role in allergic disorders, including atopic dermatitis. We examined the immunomodulatory effects of canine adipose tissue derived-MSCs (cAD-MSCs) in 3 groups: Group 1, untreated normal dog; Group 2, dogs with Dermatophagoides farinae ointment-induced atopic dermatitis; and Group 3, dogs with atopic dermatitis. Canine peripheral blood mononuclear cells (PBMCs) were collected from each group and co-cultured with cAD-MSCs. After co-culturing, PBMCs were separated and the expression of Treg cells was examined by flow cytometry. According to the results, the populations of Treg cells were increased in 3 ex vivo experimental groups, co-cultured with cAD-MSCs. These results would be important for the application of MSCs in clinical trials.
        4,000원
        12.
        2015.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 long-chain fatty acids 첨가 시 발효 48 h 에 in vitro 반추위 발효와 메탄 생성에 미치는 영향을 구명하고자 수행하였다. 반추위액은 외과적 방법으로 누관이 장착된 홀스타인에서 채취하였으며, 공시축의 사양관리는 조사료와 농후사료 6:4 비율로 하였다. 60 mL serum bottle 에 buffer 10 mL, 티모시 0.3 g, 위액 5 mL 를 각각 넣고 fatty acids(stearic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid ; 0.001%/15 mL)를 첨가한 뒤 발효시간대별(3, 6, 12, 24, 36 및 48 h)로 5 처리 3 반복 수행하였다. 발효종료시간인 48 h 에서 pH 는 oleic acid 와 linoleic acid 는 대조구에 비해 유의적(p<0.05)으로 높게 측정되었다. 48 h 에 총가스 발생량은 stearic acid 가 유의적(p<0.05)으로 높게 측정되었고 메탄 발생량은 arachidonic acid 에서 유의적(p<0.05)으로 높게 측정되었다. 건물 소화율은 발효 36 h 에서 linoleic acid 가 다른 처리구에 비해 높았으나, 발효 48 h 에서는 처리구간 유의차가 없었다. 휘발성 지방산 농도와 butyric acid 는 발효 3 h, 12 h 에서 long-chain fatty acid 처리구가 대조구에 비해서 유의적(p<0.05)으로 높게 나타났다. 3 h, 12 h 에서 acetic acid는 linoleic acid, linolenic acid 가 다른 처리구보다 유의적(p<0.05)으로 높게 나타났고, propionic acid 는 stearic acid, oleic acid 에서 다른 처리구에 비해 유의적(p<0.05)으로 높게 측정되었다. Protozoa 의 생존 수와 사멸 수는 처리구간의 차이를 나타내지 않았다. Bacteria 는 linolenic acid 와 arachidonic acid 가 다른 처리구에 비해 유의적(p<0.05)으로 높았다. Fungi 는 oleic acid 가 linoleic acid 를 제외한 나머지 처리구에서 유의적(p<0.05)으로 높게 측정되었다. 본 연구의 결과에 의해 발효 48 h 에 0.001%의 oleic acid 와 linoleic acid 의 첨가는 메탄 발생량을 감소시키는데 효과적이라는 것을 알 수 있었다.
        4,000원
        13.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 포화지방산과 불포화 지방산 첨가가 반추위 발효성상과 효소활력에 미치는 영향을 알아보기 위하여 Piromyces communis 곰팡이를 이용하여 in vitro 발효 시험을 실시하였다. 시험 Ⅰ과 Ⅱ의 대조구에는 지방산을 첨가하지 않았고, 처리구는 시험Ⅰ에서 palmitic acid, stearic acid, oleic acid를 첨가하였고, 실험 Ⅱ에서는 linoleic acid, linolenic acid, arachidonic acid를 첨가하였다. 두 실험 모두 39℃에서 7일간 (2, 3, 4, 6 및 7일) 실시되었다. 시험 Ⅰ의 가스발생량은 불포화 지방산인 oleic acid에서 가장 많이 생성되었고 H2가스의 비율은 가장 낮았다. 시험 Ⅱ의 linoleic acid 첨가구에서 2일에서 6일까지의 가스 발생량은 대조구에 비해 높았지만 이후에는 낮았다. 수소가스 생성비율은 linoleic acid 첨가구에서 가장 많았고 linolenic acid 첨가구에서 가장 낮았다. 또한 시험 Ⅰ의 pH는 6.63에서 5.85로, 시험 Ⅱ에서는 6.59에서 5.40으로 낮아졌다. Carboxymethylcellulase 활력은 발효시간(day) 경과에 따라 증가하는 경향이었고, 특히 arachidonic acid 첨가구의 증가폭이 컸다. 본 실험의 결과는 반추동물의 사료에 불포화지방산을 첨가하면 반추위곰팡이가 생성하는 수소를 불포화 지방산이 이용하여 메탄생성 억제에 도움이 될 것으로 기대된다.
        4,000원
        15.
        2011.03 구독 인증기관 무료, 개인회원 유료
        Ursolic acid is a triterpenoid compound present in many plants. This study examined the antimicrobial activity of ursolic acid against mutans streptococci (MS) isolated from the Korean population. The antimicrobial activity was evaluated by the minimum inhibitory concentration (MIC) and time kill curves of MS. The cytotoxicity of ursolic acid against KB cells was tested using an MTT assay. The MIC90 values of ursolic acid for Streptococcus mutans and Streptococcus sobrinus isolated from the Korean population were 2 μg/ml and 4 μg/ml, respectively. Ursolic acid had a bactericidal effect on S. mutans ATCC 25175 T and S. sobrinus ATCC 33478 T at > 2 × MIC (4 μg/ml) and 4 × MIC (8 μg/ml), respectively. Ursolic acid had no cytotoxic effect on KB cells at concentrations at which it exerted antimicrobial effects. The results suggest that ursolic acid can be used in the development of oral hygiene products for the prevention of dental caries.
        4,000원
        16.
        2004.12 구독 인증기관 무료, 개인회원 유료
        Human embryonic stem (ES) cells are derived from the inner cell mass of the preimplantation embryo. Human ES cells have the capacity to differentiate into various types of cells in the body. Human ES cells are indefinite source of cells for cell therapy in various degenerative disorders including neuronal disorders. Directed differentiation of human ES cells is a prerequisite for their clinical application. The objective of this study is to develop the culture condition for the derivation of neural precursor cells from human ES cells. Neural precursor cells were derived from human ES cells in a stepwise culture condition. Neural precursor cells in the form of neural rosette structures developed into neurospheres when cultured in suspension. Suspension culture of neurospheres has been maintained over 4 months. Expressions of nestin, soxl, sox2, pax3 and pax6 transcripts were upregulated during differentiation into neural precursor cells by RT-PCR analysis. In contrast, expression of oct4 was dramatically downregulated in neural precursor cells. Immunocytochemical analyses of neural precursor cells demonstrated expression of nestin and SOX1. When induced to differentiate on an adhesive substrate, neuro-spheres were able to differentiate into three lineages of neural systems, including neurons, astrocytes and oligo-dendrocytes. Transcripts of sox1 and pax6 were downregulated during differentiation of neural precursor cells into neurons. In contrast, expression of map2ab was elevated in the differentiated cells, relative to those in neural precursor cells. Neurons derived from neural precursor cells expressed NCAM, Tuj1, MAP2ab, NeuN and NF200 in immunocytochemical analyses. Presence of astrocytes was confirmed by expression of GFAP immuno-cytochemically. Oligodendrocytes were also observed by positive immuno-reactivities against oligodendrocyte marker O1. Results of this study demonstrate that a stepwise culture condition is developed for the derivation of neural precursor cells from human ES cells.
        4,000원
        17.
        2016.10 KCI 등재 서비스 종료(열람 제한)
        오귤러스 리프트와 같은 새로운 HMD기기 출시 이후 가상현실 산업은 다시 세간의 주목을 받고 있으나, 아직 콘텐츠의 다양성은 미비하며, 일부 시각적 몰입만이 극대화된 콘텐츠가 다수 인 상황이다. 물론 이와 같은 일부 콘텐츠로의 편중 현상은 아직 새로운 미디어 기반의 콘텐 츠 개발을 위한 심층적인 연구에 필요한 충분한 시간 및 재원을 충족시키지 못한 것이 그 원인 이라고 할 수 있다. 따라서 본 연구는 VR콘텐츠 산업의 지속적 발전을 위한 콘텐츠의 다양성 확보를 위해 대중에게 가장 거부감이 없으면서, 시각적 몰입 외에도 심리적 몰입 요소를 적용 할 수 있는 게임의 요소 중 이야기구조를 선정하여 ‘VR게임 콘텐츠 기획 방법론’을 제시, 향후 다양한 VR콘텐츠의 기획/제작을 위한 이론적 토대를 마련하였다.
        18.
        2016.10 서비스 종료(열람 제한)
        Background : Ginseng, one of most famous traditional oriental medicines, has been known for a number of pharmacological properties including anti-tumor, anti-diabetic, anti-fatigue, anti-stress, anti-oxidative, and anti-aging effects. 20(S)-Protopanaxadiol (PPD), a intestinal metabolite of ginsenosides, is one of the active ingredients in ginseng. In this study, we investigated the synergistic anticancer effect of 20(S)-PPD and temozolomide (TMZ) and the mechanism of 20(S)-PPD on glioblastoma cells. Methods and Results : We examined cell viability and the morphological changes of C6 cells after treatment of 20(S)-PPD and TMZ. 20(S)-PPD showed a potent antiproliferative activity against C6 cells by triggering apoptosis. 20(S)-PPD-induced apoptosis was characterized by a dose-dependent mitochondrial damage. 20(S)-PPD and TMZ had a synergistic effect in increasing mitochondrial damage via caspase 3 activation. Conclusion : These results revealed an unexpected mechanism of 20(S)-PPD and TMZ, triggering a mitochondrial-mediated apoptosis in C6 cells. Our findings encourage further studies of 20(S)-PPD as a promising chemopreventive agent against glioblastoma.
        19.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        피부의 가장자리에 위치한 표피는 개체의 생존에 절대적으로 중요하며, 기저막에 위치한 표피줄기세포에 의해 평생 끊임없이 재생되고 있다. 표피줄기세포는 한정된 세포분열을 진행하고 각질세포로 분화하는 transit amplifying (TA)세포를 만들어 냄으로써 오랜 기간 재생에 필요한 많은 각질세포를 만들어 낼 수 있다. 본 연구 에서는 표피줄기세포 세포분열 활성화 화합물로 목단으로부터 추출한 페오놀(paeonol)을 350여 개의 화합물들 로부터 검색해 냈다. 이러한 세포분열 활성화 효능은 표피줄기세포 특이적으로 나타나며, 표피줄기세포의 지표 로 알려진 p63 단백질의 발현 경향은 페오놀을 처리한 표피줄기세포에서 변화하지 않음을 유세포분석법으로 확인하였다. 콜로니형성 분석에서는 페오놀을 처리한 표피줄기세포가 1.3배 이상 더 나은 콜로니 형성능을 보여 주었다. 그리고 PCR array 분석을 통해서 페오놀의 효능은 여러 신호전달에 의해 나타남을 알 수 있었다. 이러 한 결과들로부터 페오놀이 줄기세포성에 영향을 주지 않고 표피줄기세포의 재생능력을 향상시키므로 표피줄기 세포 활성화 물질로서 화장품 소재로 적용될 수 있을 것으로 판단된다.
        20.
        2015.06 KCI 등재 서비스 종료(열람 제한)
        세포 노쇠화(cell senescence)는 나이 듦에 따른 내인성 노화 및 질병들에서 나타날 수 있는 세포의 노화인자 발현, 세포분열 정지 등의 현상으로 일컬어진다. 피부세포의 경우, 노화 및 외부요인으로 인한 세포 노쇠화가 일어나 세포분열의 정지 및 기능 이상이 관찰되며 이는 피부노화를 가속화시키는 요인이 된다. 본 연구에서는, cordycepin을 이용하여 노화된 피부세포의 세포 노쇠화 억제 및 기능 향상을 유도하여 피부노화 개선의 가능성을 제시하였다. 사람에서 유래한 섬유아세포를 이용하여 세포의 β-galactosidase 활성 세포염색 결과, 많은 계대의 세포에서 발현이 높게 나타남을 알 수 있었다. 항산화 및 항염 효과가 알려진 cordycepin을 많은 계대의 세포에 처리하였을 때 β-galactosidase 활성이 확연히 떨어짐을 확인하였고 무혈청 배지 조건에서 많은 계대 세포의 증식 및 생존율을 높이는 결과를 보였으며 세포 노쇠화와 많은 연관성이 대두되고 있는 미토콘드리아의 기능관련 실험을 진행한 결과, 높은 ROS억제능이 나타났다. 본 연구를 통하여 노화된 사람 피부 섬유아세포에서의 cordycepin의 세포 노화 개선능을 알 수 있었으며, 피부 항노화소재로서의 가능성을 확인하였다.
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