• Asian-Australasian Journal of Animal Sciences
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• 제18권10호
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• pp.1445-1450
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• 2005

This experiment was conducted to evaluate the effect of feed withdrawal (F) and heat acclimatization (A) on malebroiler and -layer chickens responses to acute heat stress (AHS) at four weeks of age. Totals of ninety male chicks of broiler or layer type were randomly allocated into 30 pens of grower batteries with raised wire floors. Chicks were subjected to F and A three times a week through the first three weeks of age. At each time, feed withdrawal and heat acclimatization (T = $35^{\circ}C$) lasted for six and four hours, respectively. Feed consumption (FC), body weight (BW), and feed conversion ratio (FCR) were recorded weekly for broiler type chickens only. At four weeks of age, all groups of chickens were exposed to AHS (T = $39{\pm}1^{\circ}C$) for three hours. Before and after AHS challenge, body temperature (Tb), heterophil (H), and lymphocyte (L) counts were recorded, and H/L ratio was calculated. Antibody (Ab) response to sheep red blood cells (SRBC) was assessed from all treatments without being exposed to AHS. Group F of broiler-type chickens weighed less (p<0.05) compared to control group. Also, both A and F groups of broiler-type chickens consumed less (p<0.05) feed when compared to control group. Acute heat stress elevated Tb of all treatment groups, however the increase was more profound (p<0.001) in broiler chicks. Broiler chicks of both A and F groups showed a tendency to have higher (p = 0.08) Tb when compared to control group. Acute heat stress elevated (p<0.001) H/L ratio in both types of chickens. Broiler chicks maintained higher (p<0.001) H/L ratio. Both F and A groups reduced (p<0.01) the level of elevation in H/L ratio compared to control groups of both types of chickens. Neither A nor F group affected the Ab production in response to SRBC. However, there was a tendency towards higher Ab responses in F group when compared to other groups in both types of chickens. Results of the present study demonstrate that previous history of feed withdrawal or episodes of heat exposures improved chicks'physiological withstanding of AHS and a tendency to improved humoral immune response.

• 한국동물생명공학회지
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• 제34권3호
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• pp.173-182
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• 2019

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 15℃ and relative humidity (RH) of 60%; temperature-humidity index (THI) = 64), and by 3 and 6 days (treatment groups) at heat stress (Ta of 35℃ 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.

• 한국초지조사료학회지
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• 제33권3호
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• pp.159-166
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• 2013

We have previously investigated the proteome changes of rice leaves under heat stress (Lee et al. in Proteomics 2007a, 7:3369-3383), wherein a group of antioxidant proteins and heat shock proteins (HSPs) were found to be regulated differently. The present study focuses on the biochemical changes and gene expression profiles of heat shock protein and antioxidant genes in rice leaves in response to heat stress ($42^{\circ}C$) during a wide range of exposure times. The results show that hydrogen peroxide and proline contents increased significantly, suggesting an oxidative burst and osmotic imbalance under heat stress. The mRNA levels of chaperone 60, HSP70, HSP100, chloroplastic HSP26, and mitochondrial small HSP responded rapidly and showed maximum expression after 0.5 or 2 h under heat stress. Transcript levels of ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and Cu-Zn superoxide dismutase (Cu-Zn SOD) showed a rapid and marked accumulation upon heat stress. While prolonged exposure to heat stress resulted in increased transcript levels of monodehydroascorbate reductase, peroxidase, glyoxalase 1, glutathione reductase, thioredoxin peroxidase, 2-Cysteine peroxiredoxin, and nucleoside diphosphate kinase 1, while the transcription of catalase was suppressed. Consistent with their changes in gene expression, the enzyme activities of APX and DHAR also increased significantly following exposure to heat stress. These results suggest that oxidative stress is usually caused by heat stress, and plants apply complex HSP- and antioxidant-mediated defense mechanisms to cope with heat stress.

• 한국응용과학기술학회지
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• 제35권3호
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• pp.807-815
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• 2018

본 연구는 열 스트레스 (heat stress, HS)에 노출된 브로일러에서 혼합 생균제의 급여가 혈액 생체지표, 면역반응, 맹장 미생물 및 생산성에 미치는 영향을 조사하였다. 총 400마리의 브로일러 수컷 (Ross 308)을 각각 100마리씩 4그룹, C (대조군, 실온 $25^{\circ}C$), HS (열 스트레스 $33^{\circ}C$), HSP (HS플러스 혼합 생균제 500, 750 mg/kg) 그룹으로 배치하였다. 브로일러의 증체량, 사료섭취, 사료요구율 및 면역기관 무게는 HSP 그룹에서 HS 그룹과 비교했을 때 증가하였다. 혈액 IgG, lymphocytes 농도는 HS 그룹에서 HSP그룹과 비교했을 때 증가하였고, heterophil과 lymphocyte(H:L)비율, 코르티코스테론 농도 및 폐사율은 낮았다. 맹장의 Lactobacillus는 HS 그룹과 비교했을 때 HSP 그룹에서 증가하였으나 Escherichia coli (E. coli), coliform bacteria, aerobic bacteria는 낮아졌다. 본 연구결과는 열 스트레스에 노출된 브로일러에게 B. subtilis, S. galilaeus 및 Sphingobacteriaceae등 3가지 균주가 포함된 혼합 생균제를 급여해주면 면역반응 증진, 미생물 균형을 유지해줌으로써 폐사율을 낮추고 생산성을 개선할 수 있음을 시사해준다.

• Asian-Australasian Journal of Animal Sciences
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• 제23권7호
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• pp.880-888
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• 2010

The ameliorative effect of salts and ascorbic acid polyphosphate supplementation on heat stress was studied in buffaloes. Adult buffaloes of either sex were randomly divided into 2 groups of 4 animals each. Group I served as control and Group II was supplemented with sodium bicarbonate, potassium carbonate and ascorbic acid polyphosphate. All the animals were exposed to two conditions of temperature and humidity: hot-dry and hot-humid in a psychrometric chamber for 4 h daily for 10 days. Blood was collected on day 1, 5 and 10 of treatment. The activities of catalase and superoxide dismutase (SOD), concentrations of serum glutathione (GSH), cortisol, sodium, potassium, and chloride and lipid peroxidation were estimated in serum. Lymphocyte proliferation was assessed in blood. The activities of catalase and SOD, serum concentration of GSH, sodium, potassium and chloride decreased while lipid peroxidation and serum cortisol increased in both groups when subjected to heat stress. Dietary supplementation resulted in further decreasing of the enzyme activities but increasing of the serum concentrations of GSH, sodium, potassium and chloride. Lipid peroxidation and serum cortisol increased in the supplemented group in both types of stress. Dietary supplementation caused an increase in lymphoproliferative response to con A. Thus, supplementation of ascorbate in addition to electrolytes relieves the animals of oxidative stress and boosts cell mediated immunity.

• 식물조직배양학회지
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• 제27권5호
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• pp.411-413
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• 2000

The ability of microspores or young pollen grains (male gametophytes) to undergo developmetal switch to embryogenic (sporophytic) pathway exemplifies the concept of totipotency as applied to haploid posmeiotic cells. As a first step pollen is devoid of positional information provided in situ by the intact anther - by isolation and cultivation in vitro in artificial media. This is inevitably accompanied by some degree of stress response in microspore/pollen. It has been shown in both monocots and dicots that intentional stress treatment (mostly starvation or heat shock) greatly stimulates embryo induction rate. Using transgenic sHSP antisense Nicotiana tabacum we show that expression of small heat shock proteins is an integral part of successful embryo and later haploid plant production from pollen grains. Our recently published data show that sHSP chaperone function is optimal in the absence of ATP.

• Animal Bioscience
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• 제34권11호
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• pp.1839-1848
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• 2021

Objective: The objective of the present study was to investigate the comparative effects of dietary functional nutrients including glutamine (Gln), chromium picolinate (Cr picolinate), vitamin C (Vit C), betaine (Bet), and taurine (Tau) on growth performance, meat quality, immune responses, and stress biomarkers in broiler chickens raised under heat stress conditions. Methods: A total of 420 21-d-old Ross 308 male broiler chickens (initial body weight = 866±61.9 g) were randomly allotted to 1 of 7 treatment groups with 6 replicates. One group was kept under thermoneutral conditions and was fed a basal diet (PC, positive control). Other 6 groups were exposed to a cyclic heat stress condition. One of the 6 groups was fed the basal diet (NC, negative control), whereas 5 other groups were fed the basal diet supplemented with 0.5% Gln, 500 ppb Cr picolinate, 250 mg/kg Vit C, 0.2% Bet, or 1.0% Tau. The diets and water were provided ad libitum for 21 d. Results: Broiler chickens in NC group had decreased (p<0.05) growth performance and immune responses measured based on cutaneous basophil hypersensitivity (CBH), but increased (p<0.05) stress responses measured based on feather corticosterone concentrations and blood heterophil:lymphocyte than those in PC group. However, none of dietary functional nutrients had a positive effect on growth performance of broiler chickens. Dietary supplementation of 250 mg/kg Vit C improved (p<0.05) CBH responses of broiler chickens, but other functional nutrients had no such an improvement in CBH responses. All functional nutrients decreased (p<0.05) stress responses of broiler chickens. Conclusion: Functional nutrients including Gln, Cr picolinate, Vit C, Bet, and Tau at the supplemental levels used in this study decrease stress responses of broiler chickens to a relatively similar extent. However, this reduction in stress responses could not fully ameliorate decreased productive performance of broiler chickens raised under the current heat stress conditions.

• 한국환경생물학회:학술대회논문집
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• 한국환경생물학회 2003년도 학술대회
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• pp.86-91
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• 2003

In this study, in order to examine whether salt and heat shock stress would alter or not contraction and relaxation of isolated rat aorta. Under anesthesia with sodium pentobarbital(50 mg Kg$^{-1}$ i.p.), male Sprague Dawley rats weighing 300-330 g were subjected to 0, heat shock combined salt stress, where as the sham group was left at modified Krebs-bicarbonate solution. To measure contractile response of vascular ring preparation isolated from rat was determined in organ bath and was recorded on physiograph connected to isometric transducer. And the strip was checked for expression of heat shock protein(Hsps) by means of western blotting. The combination group of heat and 50 mM NaCl group increased vascular contractility, and the heat and 150 mM NaCl group decreased vascular contractility for 5 hours, and then recovered for 8 hours compared to that of control. Expressin of Hsp 70 of vascular muscle of rat aorta more increased by combination of heat and NaCl treatment than those of single treatment of heat or NaCl treatment, and vascular Hsp 70 showed a little decrease at 8 hours compared at 5 hours. These result indicate that mixed environmental stress either increased or decreased in vascular contractility by combination of heat and NaCl concentration.

• Asian-Australasian Journal of Animal Sciences
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• 제25권2호
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• pp.256-260
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• 2012

The objectives of this study were to investigate the immune responses of broiler chickens fed diets supplemented with different level of chromium methionine (CrMet) in heat stress (HS) condition. Two hundred and eighty eight male broiler chickens (Ross 308) were allocated to four treatment groups (supplementation with 0, 200, 400 or 800 ppb Cr in the form of CrMet) in a completely randomized design. The experiment was conducted at heat stressed condition and all birds were kept under temperature of $33{\pm}2^{\circ}C$. Antibody titers against Newcastle disease virus (NDV) and infectious bronchitis virus (IBV), heterophil to lymphocyte ratios (H/L), and concentration of plasma cortisol (CPC) were measured at 21 and 42 d. At 42 days of age two birds were chosen randomly from each replicate, slaughtered, spleen and bursa of Fabricius were collected, weighed and expressed as a percentage of live body weight. Antibody titers against NDV and IBV at 21 and 42 days of age in broiler fed supplemental CrMet were higher than in broiler chickens fed control diet (p<0.05). CPC level in broiler chickens fed CrMet were significantly (p<0.05) decreased. Increases in lymphocyte counts and consequently a decrease in heterophil to lymphocyte ratios in broiler chickens fed 800 ppb Cr were observed at 21 and 42 d. Supplementation with CrMet had no significant effect on lymphoid organs of broilers. The results suggest that dietary CrMet supplementation at a level of 800 ppb can improve some immune responses of broiler chickens under heat stress conditions.

• 생명과학회지
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• 제26권12호
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• pp.1360-1366
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• 2016

Heat shock proteins (HSPs)은 다양한 생리학적인 또는 환경적 스트레스에 응답하여 유도된다. 그러나 HSPs의 전사 활성은 heat shock factors (HSFs)에 의해 조절 된다. 현재 연구에서는 붕어와 마우스의 간세포 배양에서 열 스트레스에 의한 heat shock factor 1 (HSF1)의 패턴 차이와 heat shock protein 70 (HSP70)의 발현을 면역분석법을 이용하여 조사하였다. 붕어의 간세포는 $33^{\circ}C$에서 trimer를 이루지만 마우스의 간세포는 $42^{\circ}C$에서 trimer를 이루었다. 이 연구는 붕어와 마우스의 HSF1은 열 스트레스로부터 다른 온도에서 반응을 한다는 것을 보여준다. 또한 재조합 단백질을 이용하여 붕어와 인간의 HSF1의 온도에 따른 활성 조건을 CD spectroscopy와 면역분석을 이용하여 조사하였다. 이러한 결과들은 인간과 마우스 HSF1과 붕어의 HSF1은 온도에 의한 활성 변화를 보이지만 그들의 최적 활성 온도는 다르다는 것을 알 수 있다.