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        검색결과 127

        1.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to determine the appropriate seeding dates by verifying the difference in winter survival and productivity of alfalfa according to fall sowing dates in the central area of South Korea. The experiment was conducted for 2 years (2020 and 2021) at the field in the Department of Animal Resources Development, NIAS located in Cheonan. Sowing dates started from September 18 to November 8 with 10 days of intervals during 2020 and 2021; SO1 (September 18), SO2 (September 28), SO3 (October 8), SO4 (October 18), SO5 (October 28), and SO6 (November 8). After sowing, the winter survival rate was measured in the spring of the following year, and the dry matter yield was measured by harvesting at 10% flowering and harvesting five times a year. SO6 failed to winter survival, and SO5 also had a lower winter survival rate than SO1~4 (p<0.05). The average annual dry matter yield of alfalfa linearly decreased with delaying sowing dates (p<0.05). The feed value did not differ in the same year by delaying the sowing date in the same year. These results suggest that sowing date should be started before October 18 to increase winter survival and productivity of alfalfa in the central area of South Korea.
        4,000원
        2.
        2022.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to investigate dry matter productivity and nitrate nitrogen content in the growth stages of barnyard millet (Echinochloa esculenta) cultivated for feed, which was treated with different nitrogen fertilization levels. An early variety of barnyard millet (cv. Shirohie) was used for the test, and the different treatments with nitrogen fertilizer were as follows: 50% (N-40 kg/ha, T1), 100% (N-80 kg/ha, reference amount, T2), 150% (N-120 kg/ha, T3), 200% (N- 160 kg/ha, T4), 250% (N-200 kg/ha, T5), and 300% (N-240 kg/ha, T6). Sowing was done on May 13, 2021 and plants were harvested for four stage; vegetative stage, elongation stage, heading stage, and milk stage. The length of the millet increased significantly as the amount of nitrogen fertilization increased during the harvest period (p<0.05), but the difference was insignificant during the milk stage (p>0.05). Moreover, barnyard millet dry matter yield increased significantly as the levels of nitrogen fertilization increased (p<0.05), but there was no significant difference in dry matter yield among nitrogen fertilization levels during the heading stage (p>0.05). Chlorophyll also was significantly higher in T5 (250%) at all harvesting times, whereas nitrate nitrogen content was highest at the vegetative stage, gradually decreased as growth progressed, and lowest at the milk stage. Finally, as the nitrogen fertilization levels increased, the nitrate nitrogen content was significantly higher in all treatment groups (p<0.05). Therefore, our results suggest that the most appropriate nitrogen fertilizer levels is between 150%–200%, considering the dry matter yield, feed ingredients and nitrate nitrogen content in barnyard millet for feed.
        4,000원
        3.
        2022.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to examine the changes in dry matter yield and growth characteristics of alfalfa (Medicago sativa L.) in response to variations in sowing dates during the autumn season of 2021-22 in a dry paddy field of Chilbo-myeon, Jeongeup-si, Jeollabuk-do. Treatments comprised four sowing dates at 10-day intervals, i.e., October 8, October 18, October 28, and November 8, 2021. The winter survival rate of alfalfa showed a significant difference between different treatments but was at a satisfactory level for all (p<0.05). The winter survival rate for the fourth sowing date, a month later than the first sowing date, was approximately 11.7% lower than that for the first sowing date. The plant height ranged between 82.3–93.1 cm and 60.5–63.7 cm at the first and second harvest, respectively, smaller at the second harvest than at the first harvest. The total dry matter yield of alfalfa was the highest at 13,316 kg/ha for the first sowing date, and the later the sowing date, the lower the dry matter yield. The protein content of alfalfa ranged between 13.6–17.3% in the first harvest, lower than the standard alfalfa protein content of 20% or more. In relative feed value, the first sowing (Oct. 8) was the most significantly higher in the first harvest (p<0.05). These results suggest that the early and mid-October sowing dates are optimum for sowing alfalfa during autumn and result in improved plant growth, dry matter yield, protein content, and winter survival compared to those at later sowing dates. Therefore, dry paddy fields can be safely employed for alfalfa cultivation with sowing dates in early and mid-October during autumn.
        4,000원
        4.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Barnyard millet (Echinochloa esculenta) can be processed through soiling, hay, and silage, depending on the weather conditions during harvesting. However, research on barnyard millet is insufficient, and standards for cultivar, seeding density, and fertilizers have not been established. This study was conducted to examine the effects of seeding density and seeding methods on dry matter yields. For this, we used the early-maturing (Shirohie millet) variety of the barnyard millet. The experimental design included different seeding density (10 kg/ha, 15 kg/ha, 20 kg/ha (standard seeding density), 25 kg/ha and 30 kg/ha), and different methods of seeding (drill seeding and broadcast seeding). The seeding date was May 13, 2021, and the harvest date was July 13, 2021. Harvesting was carried out when the heading reached 40 %. Lodging occurred at 5, 9 and 7 at 20, 25 and 30 kg/ha densities in the broadcast seeding, but not in the drill seeding. With decreasing density of seeding, tillage number showed an increasing trend in both drill seeding and broadcast seeding (p>0.05). The plant heights were comparable in both drill seeding and broadcast seeding (p>0.05). The heading stage of barnyard millet was checked July 7 for drill seeding, and, on July 8 for broadcast seeding. It took 62 days, i.e., till July 13 for the heading to reach 40 % of the output. The dry matter yield of barnyard millet was significantly higher at the seeding density of 30 kg/ha, for both the methods of seeding (p<0.05). There was no difference in the chemical composition of grain, based on the seeding method and seeding density. However, as the seeding density increased, the CP, NDF, ADF, and TDN contents increased in both drill seeding and broadcast seeding. We found that, the dry matter content was the highest at the seeding density of 30 kg/ha for both the methods of seeding, but this was only 1.3 times higher than that of 10 kg/ha. Considering the seed price and labor force involved in seeding, it is advisable to have a seeding density of 15-20 kg/ha.
        4,000원
        8.
        2016.11 구독 인증기관·개인회원 무료
        It has been reported that collagen and elastin inhibit skin wrinkle formation. Skin elasticity is closely associated with the formation of wrinkles induced by UV exposure. In this study, we investigated the protective effects Pleurotus ostreatus (P. ostreatus) on UVB irradiation induced wrinkle in hairless mice. We evaluated for their free radical-scavenging activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH), the anti-elastase activities, and for their anti-matrix metalloproteinase-1 (MMP-1) activity in human skin fibroblast cells. In the wrinkle measurement and image analysis of skin replicas, the results showed that P. ostreatus significantly inhibited wrinkle formation caused by chronic UVB irradiation. These results suggest that P. ostreatus has anti-wrinkle activity.
        9.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        돼지고기 중 5종의 곰팡이독소(아플라톡신 B1, B2, G1, G2 및 오크라톡신 A)를 분석하기 위해 0.1% 개미산을 함유한 50% 아세토니트릴용액으로 추출한 후 고체상추출칼럼을 이용하여 정제하고, LC-MS/MS로 동시 정량할 수 있는 시험법을 마련하였다. 분석조건으로 측정한 5종의 곰팡이독소 matrix-matched 표준곡선식에서 모두 상관계수 0.998이상의 상관관계를 나타내었다. 5종의 곰팡이독소 2배의 정량한계에서 10배의 정량한계로 첨가한 시료에서 평균 회수율은 72.1~109.9%로 실험 결과들이 EU 가이드라인에서 제시하는 유효성 확인을 위한 기준을 만족함으로써 시험법의 신뢰성을 확보할 수 있었다. 충청지역 유통되고 있은 돼지고기 20건에 대한 총아플라톡신 및 오크라톡신A에 대한 오염도 조사결과 정량한계 미만으로 조사되었다.
        4,000원
        11.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구는 동계 사료맥류를 활용하여 건초대용 양질 헤일리지의 생산 가능성을 검토하기위하여 맥종별 수확시기, 적정 건조시간 및 헤일리지 품질을 분석하였다. 그 결과 수확시기가 늦어질수록 건물수량과 TDN 수량은 높아지는 경향이었고, 단백질과 NDF, ADF 함량은 낮아지는 경향을 보였다(p<0.05). 헤일리지 조제를 위한 건조시간은 청보리, 귀리, 트리티케일,총체밀 모두 유숙기에는 수분함량이 높음과 동시에 기상온도도 높지 않으므로 32시간 이상예건이 필요하고, 황숙기에는 8~24시간 정도예건이 필요하며, 완숙기에는 예건이 필요 없었다. 호밀은 출수 후 10일에는 32시간 이상,출수 후 20일, 30일에서는 24시간 이상 예건이필요하였다. 헤일리지 발효품질에서 pH는 모든맥종에서 모두 수확시기가 늦어질수록 높아지는 경향을 보였고, 젖산함량은 유숙기에 가장높은 값을 보였고, 수확시기가 늦어질수록 감소하였다(p<0.05). 초산도 수확시기가 늦어짐에따라 감소하는 경향을 보였고, 낙산은 검출되지 않았다. 이상의 연구결과를 종합하여 볼 때,사료맥류로 헤일리지 조제 시 단백질함량이나발효품질 면에서는 수확이 빠를수록 유리하지만 우리나라 기상조건으로 볼 때 예건의 어려움이 있으므로, 호밀은 청예나 사일리지로 이용을 하고 청보리와 귀리, 트리티케일, 총체밀은 황숙기에 수확하여 8~24시간 정도 예건하면헤일리지로 이용 가능성이 있는 것으로 판단되었다.
        4,000원
        12.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to observe the fermentative quality and anthocyanin content in whole crop colored barley silage during storage periods and anthocyanin stability in in vitro ruminal fluid. Silages of colored barley cultivar “Boanchalbori” and normal barley cultivar “Yuyeonbori” were stored during 0, 2, 4, 6, and 12 months. The in vitro ruminal fluid was fermented for 0, 6, 12, 24, and 48 hrs. For the feed value, crude protein of colored barley silage was slightly increased in the silage compared to that of normal barley silage, and being increased up to 2 months after ensiling and thereafter maintained at the similar level. Neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents of both the barley significantly increased by prolonged storage of 2 months (p<0.05), but they were maintained at the constant level after 2 months of storing silage. Whereas TDN (total digestible nutrients) contents of them were decreased by the prolonged storage of 2 months (p<0.05), then maintained at the constant levels. The fermentative quality and pH values in both the barley silages were slightly decreased during the storage time. Lactic acid and acetic acid contents were increased during prolonged storage period, but not significantly different among treatments. Butyric acid was not detected. In the colored barley silage, pH value showed slightly lower compared to that of the normal barley silage but not significant, and lactic acid content was significantly higher than the normal barley silage (p<0.05). The total anthocyanin content in the whole crop colored barley silage decreased to 42% after 2 months of ensilage, however maintained at the constant level until 12 months of ensilage. In the case of anthocyanin stability on in vitro ruminal fluid digestion, the pH value of the ruminal fluid was slightly lower at 6, 12, 24, 48h incubation time and the content of anthocyanin was at similar levels. These results indicated that the colored barley showed higher fermentation quality, and total anthocyanin content was maintained stable at 42% level of the first value in storing silage. As the anthocyanin had higher stability in the ruminal fluid, the colored barley has a potential as functional feeds for Ruminants.
        4,000원
        13.
        2012.10 구독 인증기관·개인회원 무료
        Allomyrina dichotoma is a typical pet beetles in Korea. From 2010, similar symptoms of milky spore disease were found collectively in grubs of the species reared in insect farms. They shared a specific symptom that the skin of last instar larvae was changed softer with opaque white and infested grubs eventually died. To clarify the cause of the symptom, we collected the larvae of A. dichotoma from five farms and examined intestinal bacterial florae of them using pyrosequencing technique. From those results, a member of Paenibacillus was found only in the larvae showing the symptom of disease. Through PCR analysis using a Paenibacillus specific primer set, we obtained the partial 16S rRNA gene sequence and confirmed the microbe as Paenibacillus sp. For detailed characterizing, a whole guts was extracted from each larva showing the sign of the disease and incubated at 70℃ for 15 min to isolate spore forming bacteria. After then, each content of guts was cultured on MYPGPNAL agar medium (12.5 μg/ml of nalidixic acid) at 30℃. The 16S rRNA gene sequence analysis for six isolate showed that they were closely related to P. rigui (97.5~98.0% similarity) and to P. chinjuensis (95.9~96.6% similarity). Additional tests including API test and cellular fatty acid composition analysis were performed, but the strain couldn’t be identified at species level, suggesting it may represent novel species of the genus Paenibacillus.
        14.
        2012.06 구독 인증기관·개인회원 무료
        Ski protein is implicated in proliferation/differentiation in a variety of cells. We had previously reported that Ski protein is present in granulosa cells of atretic follicles, but not in preovulatory follicles, suggesting that Ski has a role in apoptosis of granulosa cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells; however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of the present study was to locate Ski protein in the rat ovary during luteinizationto predict the possible role of Ski. In order to examine the expression pattern of Ski protein along with the progress of luteinization, follicular growth was induced by administration of equine chorionic gonadtropin to immature female rats, and luteinization was induced by human chorionic gonadtropin treatment to mimic luteinizing hormone (LH) surge. While no Ski-positive granulosa cells were present in preovulatory follicle, Ski protein expression was induced in response to LH surge, and was maintained after the formation of the corpus luteum (CL). Though Ski protein is absent in granulosa cells of preovulatory follicle, its mRNA (c-Ski)was expressed and the level was unchanged even after LH surge. Taken together, these results demonstrated that Ski protein expression is induced in granulosa cells upon luteinization, and suggests that its expression is regulated post-transcriptionally.
        19.
        2009.12 구독 인증기관 무료, 개인회원 유료
        This study was to investigate pregnancy rate of IVM/IVF/IVC Korean cattle (registered in government) embryos according to transport time course. For the production of embryos, oocytes recovered from slaughtered excellent grade cow and highly motile frozen‐thawed bull semen (purchased from LIMC, KPN#497) was used. In vitro produced embryos were cultured in CR1aa medium for 8 days and some of them were frozen. The rate of average cleavage (>2‐cell) was 83.0% (308/371) and blastocyst rate at day 8 was 34.7% (107/308). Among in vitro produced blastocyst embryos at day 8, most healthy embryos were freshly transferred on production day and some frozen embryos were direct transferred on appropriate day. These embryos were produced in a laboratory, embryo transfer (ET) was planned in 10 areas of the remote island (Jeju) from the laboratory by airplane. Thus, we examined the pregnancy rate in recipient cow according to embryo of transport time course before ET. From embryo transferred 44 recipient cows, overall pregnancy was 40.9% (18/44), these 18 cows were all calved [single, 94% (17/18); twin, 6% (1/18)] and total embryo implantation rate was 26% (19/66). Comparing transport time in the base of 6 hr, pregnancy rate in ET group required less 4 hr (60%, 9/15) was significantly higher than that required more 6 hr (26.3%, 5/19). In direct ET of freezing embryos, the pregnancy rate was 40% (4/10). However, it was difficult to find the meaning of temperature, pH and corpus luteum quality of recipients on comparison of pregnancy rate. When the cell death level of embryos according to storage time in thermos (straw container) before ET was measured by TUNEL staining, apoptotic index was increased with storage time‐dependent. These results demonstrated that long distance transfer of IVM/IVF/IVC embryos is possible and the time of embryo transport is very important for the pregnancy rate on field trial.
        4,000원
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