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        검색결과 66

        2.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 사료내 비테인, 글라이신, 그리고 콜린의 혼합 첨가가 고온 스트레스 환경에서 노령 산란계의 생산성, 난품질, 면역 반응 및 혈액성상에 미치는 영향을 조사하고자 수행되었다. 총 336마리의 86주령 로만 갈색종 노령 산란계를 6처리 7반복, 반복당 8수씩 임의 배치하였다. 대조구는 모든 영양소 및 에너지 요구량을 충족하거나 초과하도록 배합하였다. 대조구를 제외한 사료 처리구는 0.2% 비테인, 0.62% 글라이신, 그리고 0.32% 콜린을 단독, 두 가지 혼합, 혹은 세 가지 혼합으로 사료내 첨가하였다. 실험은 8주 동안 진행되었으며, 모든 산란계는 매일 8시간 동안 평균 온도 31.7±1.7℃, 습도 57%의 고온 스트레스 조건에서 사양되었고, 이외 시간에는 평균 온도 27±1.3℃, 습도 57%에서 사양하였다. 실험 결과, 비테인, 글라이신 및 콜린의 첨가는 생산성, 난품질, 그리고 면역 반응에 유의적인 영향을 미치지 않았다. 그러나, 0.2% 비테인과 0.62% 글라이신을 혼합 첨가한 처리구에서 혈청 알라닌 아미노전이효소 농도가 유의적으로 감소했다. 하지만, 다른 혈청 지표들은 처리간 유의적인 차이가 관찰되지 않았다. 결론적으로, 현재 수준에서 사료내 비테인, 글라이신, 그리고 콜린의 혼합 첨가는 고온 스트레스 환경에서 사양되는 노령 산란계의 생산성, 난품질, 면역 반응 및 혈액 성상에 긍정적인 영향을 미치지 않는다고 판단된다.
        4,000원
        3.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of the present experiment was to investigate the effects of dietary vitamin C (VC), vitamin E (VE), and betaine (BT) supplementations on productive performance, egg quality, relative organ weights, liver visual characteristics, antioxidant status, immune response, and stress indicator in laying hens raised under heat stress conditions. A total of 280 47-wk-old Hy-Line Brown laying hens were allotted to 1 of 4 dietary treatments with 7 replicates in a completely randomized design. Each replicate had 10 birds per cage. The basal diet was formulated to meet or exceed the requirement estimates for Hy-Line Brown laying hens. Three additional diets were prepared by adding 250 mg/kg VC, 250 mg/kg VE, or 3,000 mg/kg BT to the basal diet. The experimental diets and water were provided to hens on an ad libitum basis for 8 wk. Average daily room temperature and relative humidity were 30.7±1.41℃ and 72.5±11.61%, respectively. Results indicated that hens fed diets containing 250 mg/kg VE had a less (p<0.05) egg production rate than other dietary treatments. For egg quality, hens fed diets containing 3,000 mg/kg BT had a less (p<0.05) eggshell thickness than those fed the diets containing 250 mg/kg VC or 250 mg/kg VE. For antioxidant status, there was a tendency (p=0.09) for the least malondialdehyde (MDA) concentrations in the liver for BT treatment. A tendency (p=0.05) was observed for less blood heterophil:lymphocyte ratio in BT treatment as compared to other treatments. In conclusion, dietary supplementation of 250 mg/kg VC, 250 mg/kg VE, and 3,000 mg/kg BT has no beneficial effects on productive performance, egg quality, relative organ weights, liver visual characteristics, and immune responses of laying hens raised under the current heat stress conditions. However, dietary supplementation of 3,000 mg/kg BT alleviates antioxidant status and stress response of laying hens exposed to heat stress.
        4,200원
        4.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 고온 환경에서 사료내 트립토판과 나이아신의 첨가가 산란계의 생산성, 난품질, 지방간 지표 및 혈액성상에 미치는 상호작용 효과를 조사하고자 수행되었다. 총 384수의 25주령 로만 갈색종 산란계를 4처리 8반복으로 반복당 12수씩 무작위 임의 배치하였다. 기본 사료는 트립토판과 나이아신의 추가적인 첨가는 없으며 모든 영양소 및 에너지는 로만갈색종 산란계의 요구량에 충족하거나 초과하도록 배합되었다. 사료 처리구는 2 × 2 요인 실험 설계법으로 두 가지 수준의 트립토판(0 및 0.16%)과 두 가지 수준의 나이아신(0 및 0.03%)이 포함되었다. 모든 산란계의 사양환경은 일반 농가에서 낮시간에 온도가 올라가는 점을 고려하여 일일 중 8시간은 온도 31.4 ± 1.17℃, 습도 86.0 ± 4.28%으로 설정하였으며, 나머지 16시간은 온도 26.7 ± 1.10℃, 습도 61.7 ± 6.34%로 유지하여 주기적인 고온 환경을 조성하였다. 실험은 10주간 진행되었다. 실험 결과 사료내 트립토판과 나이아신의 주요 효과와 상호작용은 나타나지 않았다. 이와 유사하게, 난각 강도, 난각 두께, 난각색, 난황색 및 호우유닛에 대한 상호작용 도 나타나지 않았다. 주요 효과로 0.03%의 나이아신 첨가는 난황색을 유의적으로 감소시켰으나 호우유닛은 유의적으로 증가시켰다. 하지만, 0.16%의 트립토판 첨가는 난품질에 영향을 끼치지 않았다. 지방간 지표와 혈액성상에서 사료내 트립토판과 나이아신의 주요 효과 및 상호작용은 나타나지 않았다. 결론적으로, 본 연구에서 설정한 농도의 사료내 트립토판과 나이아신의 첨가는 고온 환경에서 사양되는 산란계의 생산성, 난품질, 지방간 지표 및 혈액성상에 긍정적인 영향을 미치지 않았다.
        4,200원
        5.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The impact of heat stress (HS) on reproductive performance and its problems in cows remains to be investigated in Bangladesh. The study was, therefore, aimed to evaluate the effect of HS on fertility and reproductive health problems of dairy cows in a selected area of Bangladesh. A total of 1,095 cows from 500 farms were included in this study. The climate-related data were recorded daily basis for every month in a year and temperature-humidity index (THI) values were calculated to determine the level of HS. Concurrently, data on fertility parameters [number of services per conception (NSC), conception rate (CR) and calving to the first service interval (CFSI)], and reproductive problems were collected through a pre-defined questionnaire. The results show that crossbred [Native x Holstein-Friesian, (HF)] cows were more vulnerable (p < 0.05) to a magnitude of HS effects considering physiological parameters of cows [age, body condition score (BCS), parity and milk yield]. Regarding fertility, HS had no effect on NSC, CR and CFSI in both native and crossbred cows (p > 0.05). The findings on the reproductive problems indicate that HS had significant influence on the prevalence of anestrus (χ2 = 21.814, p < 0.05) and retained placenta (χ2 = 24.632, p < 0.05) in cows. Of note, the prevalence of repeat breeding syndrome was 2.5 folds higher in stress condition than in no stress condition. Abortion and dystocia were not influenced by HS. In conclusion, HS does not influence the fertility parameters of cows studied; however, anestrus and retained placenta are likely to occur under HS conditions in cows.
        4,000원
        6.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Lonicera caerulea (Honey berry, HB) has been used in medical treatment in Russia, Japan, China and Korea. It has high level of vitamin C and polyphenolics. Polyphenolics can improve anti-inflammatory effect and prevent cancer, diabetes mellitus type 2. Also, Vitamin C is a representative anti-oxidant. however, it is still unknown what effect it will have on the oxidation stress of the reproductive system. In previous studies, ROS can be produced when it is exposed to heat stress and has negative effect on sperm’s maturation, capacitation, hyperactivation, acrosome reaction and fusion of egg and sperm. Therefore, the purpose of this study is to investigate the antioxidant effects of L. Caerulea on the sperm and mice. At first, it conducted using ICR mouse (n = 20) for 4 weeks. There are four groups of mice (n = 5 per group). Also, L. Caerulea was taken by oral gavage. Group I (control) kept at 23℃-27℃ and administer D.W (0.5 mL/day), Likewise, Group II (HB) kept at room temperature but gave HB (250 mg/kg, 0.5 mL/day), Group III (HB + HS) received heat stress (40℃) using hyperthermia induction chamber and gave HB at same dose. and Group IV (HS) exposed heat stress only. Mainly, we showed degree of gene expression using Western blot in SOD, HSP 70, 17β-HSD and Real-time PCR. It can find correlation between intracellular activity like steroid hormone, apoptosis under ROS and antioxidant activity of L. Caerulea.
        4,000원
        7.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study the effect of vitamin C administration on pregnancy rates during summer heat stress in dairy cows was examined. A total of 80 Holstein-Friesian cows were divided into control and treatment groups (n = 40 each). Control group animals were given 10 mL isotonic normal saline, and treatment group, Vitamin C (4 mg/kg) on artificial insemination day (day 0) and 4th, 8th and 12th day post insemination. Pregnancy diagnosis was performed on 30th day post insemination by ultrasonography. Blood samples were randomly taken from 11 animals from each group. Serum P4, GSH, MDA and plasma 8-OHdG levels were determined by using ELISA method. Results showed that 8-OHdG levels were lower in treatment group on day 4, 8 and 12 (p < 0.05) compared with the control group. Similarly, pregnancy rate was higher in treatment group (32.5%) than control (22.5%), respectively. However, MDA, P4 and GSH levels were similar in both groups at 4th, 8th and 12th day. A gradual increase in P4, and MDA levels, and a strong positive correlation between 0, 4th (r = 0.54), 4, 8th (r = 0.59) and 8, 12th (r = 0.51) day was found. Similarly, GSH levels also showed positive correlation at days 0, 4th (r = 0.47) and 4, 8th (r = 0.56). However, a strong negative correlation (r = -0.56) between MDA day 0, and GSH day 8 was found. In conclusion, vitamin C application during insemination period in postpartum cows increases pregnancy rate, and reduces oxidative stress metabolite 8-OHdG levels.
        4,000원
        9.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, an AISI 316 L alloy was manufactured using a selective laser melting (SLM) process. The tensile and impact toughness properties of the SLM AISI 316 L alloy were examined. In addition, stress relieving heat treatment (650oC / 2 h) was performed on the as-built SLM alloy to investigate the effects of heat treatment on the mechanical properties. In the as-built SLM AISI 316 L alloy, cellular dendrite and molten pool structures were observed. Although the molten pool did not disappear following heat treatment, EBSD KAM analytical results confirmed that the fractions of the low- and high-angle boundaries decreased and increased, respectively. As the heat treatment was performed, the yield strength decreased, but the tensile strength and elongation increased only slightly. Impact toughness results revealed that the impact energy increased by 33.5% when heat treatment was applied. The deformation behavior of the SLM AISI 316 L alloy was also examined in relation to the microstructure through analyses of the tensile and impact fracture surfaces.
        4,000원
        11.
        2020.12 구독 인증기관 무료, 개인회원 유료
        Heat shock proteins (HSPs) are highly conserved cellular proteins that contribute to adaptive responses of organisms to a variety of stressors. In response to stressors, cellular levels of HSPs are increased and play critical roles in protein stability, folding and molecular trafficking. The mRNA expression pattern of two well-known heat shock protein transcripts, HSP70 and HSP90 were studied in two tissues of nerve ganglia, cerebral ganglion and pleuropedal ganglion of Pacific abalone (Haliotis discus hannai). It was observed that both HSP70 and HSP90 transcripts were upregulated under heat stress in both ganglion tissues. Expression level of HSP70 was found higher than HSP90 in both ganglia whereas cerebral ganglion showed higher expression than pleuropedal ganglion. The HSP70 and HSP90 showed higher expression at Day-1 after exposed to heat stress, later decreased at Day-3 and Day-7 onwards. The present result suggested that HSP70 and HSP90 synthesize in nerve ganglion tissues and may provide efficient protection from stress.
        4,000원
        13.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The occurrence of exotic weeds and their influx into farmlands due to climate change poses many problems. Therefore, it is necessary to generate a prediction model for the occurrence pattern of these exotic weeds based on scientific evidence and devise prevention measures. The photosynthetic apparatus is known as the most temperaturesensitive component of a plant cell and its initial response to temperature stress is to inhibit the activation of photosystem II. This study investigated the potential of OJIP transients in assessing temperature stress in exotic weeds. The four exotic weeds currently flowing into Korean farmlands include Amaranthus spinosus, Conyza bonariensis, Crassocephalum crepidioides, and Amaranthus viridis. These weeds were treated at 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, and 40°C and the OJIP curves and JIP parameters were measured and analyzed. The results showed that heat and chilling stress affected the photosystem II (PSII) electron transport of A. spinosus, whereas C. crepidioides and A. viridis were more affected by high-temperature stress than by low-temperature stress. Lastly, C. bonariensis showed resistance to both high and low-temperature stress. The results of this study suggest that OJIP transients and JIP parameters can be used to analyze damage to the photosynthetic apparatus by temperature stress and that they can serve as sensitive indicators for the occurrence pattern of exotic weeds.
        4,200원
        14.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this analysis, the analytical model was verified through the normal mode analysis of the piston for the 2.9 liter IDI (indirect injection) engine. Heat transfer analysis was carried out by selecting two cases of applied temperature using the validated model. The first case was a condition of 350℃ on the piston upper surface and 100℃ on the piston body and inner wall. In the second case, the conditions were set to give a temperature of 400℃ on the upper surface of the piston and 100℃ on the piston body and the inner wall. In addition, the temperature distribution due to heat transfer was obtained for the pistons with boundary conditions of two cases, and then the thermal stress distribution due to thermal expansion was obtained using the input. Using this analysis result, the thermal stress caused by thermal expansion due to the thermal conduction of the piston is examined and used as the basic data for design.
        4,000원
        15.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed to investigate the effect of heat-stressed environment on rumen microbial diversity in Holstein cows. Rectal temperature and respiration rate were measured and rumen fluid was collected under normal environment (NE; Temperature humidity index (THI)=64.6) and heat-stressed environment (HE; THI=87.2) from 10 Holstein cows (60±17.7 months, 717±64.4 kg) fed on the basis of dairy feeding management in National Institute of Animal Science. The rumen bacteria diversity was analyzed by using the Illumina HiSeq™ 4000 platform. The rectal temperature and respiratory rate were increased by 1.5゚C and 53 breaths/min in HE compared to that in NE, respectively. In this study, HE exposure induced significant changes of ruminal microbe. At phylum level, Fibrobacteres were increased in HE. At genus level, Ruminococcaceae bacterium P7 and YAD3003, Butyrivibrio sp. AE2032, Erysipelotrichaceae bacterium NK3D112, Bifidobacterium pseudolongum, Lachnospiraceae bacterium FE2018, XBB2008, and AC2029, Eubacterium celulosolvens, Clostridium hathewayi, and Butyrivibrio hungatei were decreased in HE, while Choristoneura murinana nucleopolyhedrovirus, Calothrix parasitica, Nostoc sp. KVJ20, Anabaena sp. ATCC 33047, Fibrobacter sp. UWB13 and sp. UWB5, Lachnospiraceae bacterium G41, and Xanthomonas arboricola were increased in HE. In conclusion, HE might have an effect to change the rumen microbial community in Holstein cows.
        4,000원
        16.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The results of internal temperature. productivity and immunity analysis of the laying hen house by the thermal environment and the supply of cold drinking water were as follows. The external temperature was changed from the minimum of 18℃ at night and the maximum of 36℃ during the day, and the internal temperature of the laying hens varied from 20~31℃. Thermal imaging analysis showed that the body temperature of the laying hen decreased by 2.4℃ with the supply of drinking water. The laying hen amount increased 2.36g and laying hen rate increased 3.62%p. Albumin increased 6.1%, decreased AST 15%, and decreased cholesterol 12.7%. Immune activators increased and T cells and B cells increased to increase immunity.
        4,000원
        17.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to investigate effect of heat stress on expression levels of plasminogen activators (PAs) related mRNAs and proteins, and changes of PAs activity in porcine endometrial explants. The endometrial explants (200 ± 50 mg) were isolated from middle part of uterine horn at follicular phase (Day 19-21) and were pre-incubated in serum-free culture medium at 38.5oC in 5% CO2 for 18 h. Then, the tissues were transferred into fresh medium and were cultured at different temperature (38.5, 39.5, 40.5 or 41.5oC) for 24 h. The expression level of urokinase-type PA (uPA), type-1 PA inhibitor (PAI-1), type-2 PAI (PAI-2), and heat shock protein-90 (HSP-90) mRNA were analysis by reverse-transcription PCR and proteins were measured by western blotting. The supernatant were used for measurement of PAs activity. In results, mRNA and protein levels of HSP-90 was higher in 41.5oC treatment groups than other treatment groups (p < 0.05). The expression of uPA, PAI-1, and PAI-2 mRNA were slightly increased by heat stress, however, there were no significant difference. Heat stress condition suppressed expression of active uPA and PAI-2 proteins (p < 0.05), whereas PAI-1 protein was increased (p < 0.01). Although PAI-1 protein was increased and active uPA was decreased, PAs activity was greatly enhanced by exposure of heat stress (p < 0.05). These results suggest that heat stress condition could change intrauterine microenvironment through regulation of PAs activity and other factors regarding with activation of PAs might be regulate by heat stress. Therefore, more studies regarding with regulatory mechanism of PAs activation are needed.
        4,000원
        18.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        베트남 메콩 델타 지역은 베트남에서도 쌀 생산이 활발히 이루어지는 지역으로 꼽히고 있으나 기후온난화에 따른 고온 현상 증가로 쌀생산량 감소의 우려가 증대되고 있다. 이에 고온에 따른 벼 피해발생 현황 및 대응 기술에 대한 정보를 제공하고자 한다. 베트남의 평균기온은 2060년 까지 약 2.7oC 증가, 35oC 이상의 폭염은 2030년까지 2달 이상 길어질 것으로 예측되고 있으며 기온상승에 따라 기온이 높은 작기의 벼 생산량이 감소되고 있다. 벼 개화기 온도가 33oC 이상으로 높을 시, 화분의 감수분열에 영향을 미쳐 화분의 활력이 저하되며 수술에서 약의 개열이 감소되어 화분의 방출이 감소될 뿐만 아니라 화분이 암술의 주두에 부착하여 발아 시 발아율을 낮추어 불임 발생이 증가하게 된다. 베트남의 벼 연구소는 고온에 대비하여 베트남 벼 생산의 안정화를 위해서 개화기에 내열성을 가지는 품종 육성 뿐만 아니라 이른 아침에 개화할 수 있는 품종을 육성하고 있다. 또한 재배 적인 측면에서 고온 피해를 줄일 수 있도록 벼 재배시기를 조절하여 기존 3기작에서 고온피해가 큰 시기의 재배를 제외한 2기작으로 재배하는 반면 파종 및 이앙시기를 조절하여 벼의 생육량을 충분히 확보하여 2기작에 따른 수량감소를 최소화하는 연구가 필요하다. 더불어 벼를 재배하지 못하는 무더운 계절에는 농업인의 소득보존을 위해 논을 이용한 물고기 양식 기술 도입하는 것도 필요하며, 시비 방법 등의 개선을 통한 벼 생육량 조절, 물관리 기술 개발을 통한 포장 미세기상변화 등의 연구가 필요할 것으로 판단된다.
        4,000원
        19.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed to evaluate the effect of heat stress on the status of physiological responses, blood parameter, serum T3 and cortisol, and heat shock proteins (HSP 27, 70, and 90) of Hanwoo cattle. Six Hanwoo steers (242.8 ± 7.2 kg of BW) were housed in the climate-controlled respiration chambers. The experiment consisted of 7 days (control; 0 day) at thermoneutral (air temperature (Ta) of 15oC and relative humidity (RH) of 60%; temperature-humidity index (THI) = 64), and by 3 and 6 days (treatment groups) at heat stress (Ta of 35oC and RH of 60%; THI = 87). Body temperature of each parts (frank, rump, perineum and foot) and rectal temperature elevated in heat stress groups (3 days and 6 days) than the control group (0 day). Respiration rates increased in 3 days and 6 days (88.5 ± 0.96 bpm and 86.3 ± 0.63 bpm, respectively) from 0 days (39.5 ± 0.65 bpm). Feed intake significantly decreased in heat stress groups (3 days and 6 days, 3.7 ± 0.14 kg and 4.0 ± 0.15 kg, respectively) than the control group (0 day, 5.0 ± 0.00 kg). In addition, final BW significantly decreased in heat stress groups (3 days and 6 days, 211.8 ± 4.75 kg and 215.5 ± 3.50 kg, respectively) than the control group (0 day, 240.0 ± 25.00 kg). However, heat stress has no significant effect on blood parameter, serum T3 and cortisol. Nevertheless, heat stress increased HSPs mRNA expression in liver tissue, and serum concentration of HSPs. Despite Hanwoo cattle may have high adaptive ability to heat stress, our results suggested that heat stress directly effect on body temperature and respiration rate as well as serum and tissue HSPs. Therefore, we are recommended that HSPs could be the most appropriate indicators of Hanwoo cattle response to heat stress.
        4,000원
        20.
        2018.11 구독 인증기관·개인회원 무료
        Lonicera Caerulea(Honey berry) has been used in medical treatment in Russia, Japan, China and Korea. It has high level of vitamin C and polyphenolics. Polyphenolics can improve anti-inflammatory effect and prevent cancer, diabetes mellitus type 2. Also, Vitamin C is a representative anti- oxidant. however, It is still unknown what effect it will have on the oxidation stress of the reproductive system. In previous studies, ROS can be produced when it is exposed to heat stress and has negative effect on sperm's maturation, capacitation, hyperactivation, acrosome reaction and fusion of egg and sperm. Therefore, The purpose of this study is to investigate the antioxidant effects of L.caerulea on the sperm and egg cells of mice. At first, it conducted using ICR mouse(n=20) during 4 weeks. There are four groups of mouse(n=5 per group). Also, L.caerulea was taken by oral gavage. Group Ⅰ(control) kept at 23℃~27℃ and administer D.W(0.5ml/day), Likewise, Group Ⅱ(HB) kept at room temperature but gave HB(0.5ml/day), Group Ⅲ (HB+HS) received heat stress (40℃) using hyperthermia induction chamber and gave HB at same dose. and Group Ⅳ(HS) exposed heat stress only. Mainly, we showed degree of gene expression using Western blot in SOD, HSP 70, 17β-HSD and Real time PCR. It can find correlation between intracellular activity like steroid hormone, apoptosis under ROS and antioxidant activity of L.caerulea.
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