• Title/Summary/Keyword: Heat stress

Search Result 410, Processing Time 0.276 seconds

Blood amino acids profile responding to heat stress in dairy cows

  • Guo, Jiang;Gao, Shengtao;Quan, Suyu;Zhang, Yangdong;Bu, Dengpan;Wang, Jiaqi
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.31 no.1
    • /
    • pp.47-53
    • /
    • 2018
  • Objective: The objective of this experiment was to investigate the effects of heat stress on milk protein and blood amino acid profile in dairy cows. Methods: Twelve dairy cows with the similar parity, days in milk and milk yield were randomly divided into two groups with six cows raised in summer and others in autumn, respectively. Constant managerial conditions and diets were maintained during the experiment. Measurements and samples for heat stress and no heat stress were obtained according to the physical alterations of the temperature-humidity index. Results: Results showed that heat stress significantly reduced the milk protein content (p<0.05). Heat stress tended to decrease milk yield (p = 0.09). Furthermore, heat stress decreased dry matter intake, the concentration of blood glucose and insulin, and glutathione peroxidase activity, while increased levels of non-esterified fatty acid and malondialdehyde (p<0.05). Additionally, the concentrations of blood Thr involved in immune response were increased under heat stress (p<0.05). The concentration of blood Ala, Glu, Asp, and Gly, associated with gluconeogenesis, were also increased under heat stress (p<0.05). However, the concentration of blood Lys that promotes milk protein synthesis was decreased under heat stress (p<0.05). Conclusion: In conclusion, this study revealed that more amino acids were required for maintenance but not for milk protein synthesis under heat stress, and the decreased availability of amino acids for milk protein synthesis may be attributed to competition of immune response and gluconeogenesis.

Effects of heat stress on body temperature, milk production, and reproduction in dairy cows: a novel idea for monitoring and evaluation of heat stress - A review

  • Liu, Jiangjing;Li, Lanqi;Chen, Xiaoli;Lu, Yongqiang;Wang, Dong
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.32 no.9
    • /
    • pp.1332-1339
    • /
    • 2019
  • Heat stress exerts a substantial effect on dairy production. The temperature and humidity index (THI) is widely used to assess heat stress in dairy operations. Herein, we review the effects of high temperature and humidity on body temperature, feed intake, milk production, follicle development, estrous behavior, and pregnancy in dairy cows. Analyses of the effects of THI on dairy production have shown that body temperature is an important physiological parameter in the evaluation of the health state of dairy cows. Although THI is an important environmental index and can help to infer the degree of heat stress, it does not reflect the physiological changes experienced by dairy cows undergoing heat stress. However, the simultaneous measurement of THI and physiological indexes (e.g., body temperature) would be very useful for improving dairy production. The successful development of automatic detection techniques makes it possible to combine THI with other physiological indexes (i.e., body temperature and activity), which could help us to comprehensively evaluate heat stress in dairy cows and provide important technical support to effectively prevent heat stress.

Effect of Moisture on the Heat Stress of Fire Fighters (소방관의 열 압박에 대한 수분의 영향)

  • Yoon, Kee Jong
    • Textile Science and Engineering
    • /
    • v.56 no.1
    • /
    • pp.51-58
    • /
    • 2019
  • The greatest cause of fatality of fire fighters is heat stress rather than suffocation or burns. Heat stress increases the probability of heart attacks to a great extent and this was found to be the major cause of fatality of fire fighters. The effect of humidity on heat stress has been studied and is widely documented, however it appears that not enough attention is practiced in fire fighting. As fire fighter turnout gear often get wet when they are fighting fire, this paper attempts emphasize the importance of trying to keep the turnout gear as dry as possible to reduce the damaging effect of moisture on the heat stress that fire fighters experience. When fire fighters enter burning buildings other fire fighters spray water from a distance at the point of entry to reduce the intensity of fire there. The effect of added moisture on the temperature and relative humidity between the internal layers of the turnout gear is studied to infer the effect on heat stress. Preliminary experiments exposing a multilayer assembly whose outer layer is either conditioned or wetted on a radiant heat transfer equipment and measuring the change in temperature and humidity at two locations between the layers suggest that the transport of moisture carrying the external heat inward has a significant effect on the heat stress a fire fighter might experience. The data is analyzed with a typical heat stress index table as a first approximation of the heat stress the fire fighter might experience. The results suggests that the presence of moisture has extensive effect on the heat stress and that they should try to keep their turnout gear as dry as possible.

Korean ginseng extract ameliorates abnormal immune response through the regulation of inflammatory constituents in Sprague Dawley rat subjected to environmental heat stress

  • Song, Ji-Hyeon;Kim, Kui-Jin;Choi, Seo-Yun;Koh, Eun-Jeong;Park, JongDae;Lee, Boo-Yong
    • Journal of Ginseng Research
    • /
    • v.43 no.2
    • /
    • pp.252-260
    • /
    • 2019
  • Background: Increases in the average global temperature cause heat stress-induced disorders by disrupting homeostasis. Excessive heat stress triggers an imbalance in the immune system; thus protection against heat stress is important to maintain immune homeostasis. Korean ginseng (Panax ginseng Meyer) has been used as a herbal medicine and displays beneficial biological properties. Methods: We investigated the protective effects of Korean ginseng extracts (KGEs) against heat stress in a rat model. Following acclimatization for 1 week, rats were housed at room temperature for 2 weeks and then exposed to heat stress ($40^{\circ}C$/2 h/day) for 4 weeks. Rats were treated with three KGEs from the beginning of the second week to the end of the experiment. Results: Heat stress dramatically increased secretion of inflammatory factors, and this was significantly reduced in the KGE-treated groups. Levels of inflammatory factors such as heat shock protein 70, interleukin 6, inducible nitric oxide synthase, and tumor necrosis factor-alpha were increased in the spleen and muscle upon heat stress. KGEs inhibited these increases by down-regulating heat shock protein 70 and the associated nuclear $factor-{\kappa}B$ and mitogen-activated protein kinase signaling pathways. Consequently, KGEs suppressed activation of T-cells and B-cells. Conclusion: KGEs suppress the immune response upon heat stress and decrease the production of inflammatory cytokines in muscle and spleen. We suggest that KGEs protect against heat stress by inhibiting inflammation and maintaining immune homeostasis.

Improvement of heat and drought photosynthetic tolerance in wheat by overaccumulation of glycinebetaine

  • Wang, Gui-Ping;Hui, Zhen;Li, Feng;Zhao, Mei-Rong;Zhang, Jin;Wang, Wei
    • Plant Biotechnology Reports
    • /
    • v.4 no.3
    • /
    • pp.213-222
    • /
    • 2010
  • Within their natural habitat, crops are often subjected to drought and heat stress, which suppress crop growth and decrease crop production. Causing overaccumulation of glycinebetaine (GB) has been used to enhance the crop yield under stress. Here, we investigated the response of wheat (Triticum aestivum L.) photosynthesis to drought, heat stress and their combination with a transgenic wheat line (T6) overaccumulating GB and its wild-type (WT) Shi4185. Drought stress (DS) was imposed by controlling irrigation until the relative water content (RWC) of the flag leaves decreased to between 78 and 82%. Heat stress (HS) was applied by exposing wheat plants to $40^{\circ}C$ for 4 h. A combination of drought and heat stress was applied by subjecting the drought-stressed plants to a heat stress as above. The results indicated that all stresses decreased photosynthesis, but the combination of drought and heat stress exacerbated the negative effects on photosynthesis more than exposure to drought or heat stress alone. Drought stress decreased the transpiration rate (Tr), stomatal conductance (Gs) and intercellular $CO_2$ concentration (Ci), while heat stress increased all of these; the deprivation of water was greater under drought stress than heat stress, but heat stress decreased the antioxidant enzyme activity to a greater extent. Overaccumulated GB could alleviate the decrease of photosynthesis caused by all stresses tested. These suggest that GB induces an increase of osmotic adjustments for drought tolerance, while its improvement of the antioxidative defense system including antioxidative enzymes and antioxidants may be more important for heat tolerance.

The Effect of Hwangryunhaedok-tang on the c-fos Level in Mice Exposed to Heat Stress (황련해독탕(黃連解毒湯)이 외열 스트레스(화사(火邪))에 의한 동물모델에서 c-fos 발현에 미치는 영향 연구)

  • Hwang, Deok-Sang;Kim, Hyo-Geun;Kim, Tae-Mi;Lee, Tae-Hee;Oh, Myung-Sook
    • The Journal of Korean Obstetrics and Gynecology
    • /
    • v.27 no.3
    • /
    • pp.1-11
    • /
    • 2014
  • Objectives: Hwangryunhaedok-tang (HH) is a representative heat clearing multiherb prescription. We evaluated the protective effect of HH against heat stress exposure in mice. Methods: Six weeks old ICR mice were used for this study. After $43^{\circ}C$ heat stress for 15 minutes, we evaluated the changes of motor activity and c-fos expression level to determine the proper heat stress and evaluation time. The subjects were divided into 4 groups (1. control group, 2. heat stress group with normal saline, 3. heat stress group with administration of 100 mg/kg, and 4. heat stress group with administration of 1000 mg/kg). After oral administration of HH once a day for 3 days, 2, 3, 4 groups were exposed to $43^{\circ}C$ heat stress for 15 minutes. Then, we evaluated the motor activity for 120 minutes and analyzed the c-fos expression using western blot. We investigated the effect of HH and its ingredients on c-fos expressions after heat stress. The mice were administrated HH, Scutellariae Radix, Coptidis Rhizoma, Phellodendri Cortex, and Gardeniae Fructus for 3 days. After one hour of last treatment, the mice were exposed to heat stress at $43^{\circ}C$ for 15 min. After two hours, the hypothalamus was dissociated and lysed to measure c-fos expression. Results: After oral administration of HH for 3 days, motor activity was recovered insignificantly. 100 mg/kg HH treatment reduced the c-fos expression after heat stress but insignificantly. Among the ingredients of HH, Coptidis Rhizoma and Scutellariae Radix treatment groups significantly reduced the c-fos after stress. Conclusions: These results show that Hwangryunhaedok-tang may be effective to reduce the heat stress response.

Korean Red Ginseng and Korean black ginseng extracts, JP5 and BG1, prevent hepatic oxidative stress and inflammation induced by environmental heat stress

  • Song, Ji-Hyeon;Kim, Kui-Jin;Chei, Sungwoo;Seo, Young-Jin;Lee, Kippeum;Lee, Boo-Yong
    • Journal of Ginseng Research
    • /
    • v.44 no.2
    • /
    • pp.267-273
    • /
    • 2020
  • Background: Continuous exposure to high temperatures can lead to heat stress. This stress response alters the expression of multiple genes and can contribute to the onset of various diseases. In particular, heat stress induces oxidative stress by increasing the production of reactive oxygen species. The liver is an essential organ that plays a variety of roles, such as detoxification and protein synthesis. Therefore, it is important to protect the liver from oxidative stress caused by heat stress. Korean ginseng has a variety of beneficial biological properties, and our previous studies showed that it provides an effective defense against heat stress. Methods: We investigated the ability of Korean Red Ginseng and Korean black ginseng extracts (JP5 and BG1) to protect against heat stress using a rat model. We then confirmed the active ingredients and mechanism of action using a cell-based model. Results: Heat stress significantly increased gene and protein expression of oxidative stress-related factors such as catalase and SOD2, but treatment with JP5 (Korean Red Ginseng extract) and BG1 (Korean black ginseng extract) abolished this response in both liver tissue and HepG2 cells. In addition, JP5 and BG1 inhibited the expression of inflammatory proteins such as p-NF-κB and tumor necrosis factor alpha-α. In particular, JP5 and BG1 decreased the expression of components of the NLRP3 inflammasome, a key inflammatory signaling factor. Thus, JP5 and BG1 inhibited both oxidative stress and inflammation. Conclusions: JP5 and BG1 protect against oxidative stress and inflammation induced by heat stress and help maintain liver function by preventing liver damage.

Comparative transcriptome analysis of heat stress responsiveness between two contrasting ginseng cultivars

  • Jayakodi, Murukarthick;Lee, Sang-Choon;Yang, Tae-Jin
    • Journal of Ginseng Research
    • /
    • v.43 no.4
    • /
    • pp.572-579
    • /
    • 2019
  • Background: Panax ginseng has been used in traditional medicine to strengthen the body and mental well-being of humans for thousands of years. Many elite ginseng cultivars have been developed, and ginseng cultivation has become well established during the last century. However, heat stress poses an important threat to the growth and sustainable production of ginseng. Efforts have been made to study the effects of high temperature on ginseng physiology, but knowledge of the molecular responses to heat stress is still limited. Methods: We sequenced the transcriptomes (RNA-Seq) of two ginseng cultivars, Chunpoong (CP) and Yunpoong (YP), which are sensitive and resistant to heat stress, respectively, after 1- and 3-week heat treatments. Differential gene expression and gene ontology enrichment along with profiled chlorophyll contents were performed. Results: CP is more sensitive to heat stress than YP and exhibited a lower chlorophyll content than YP. Moreover, heat stress reduced the chlorophyll content more rapidly in CP than in YP. A total of 329 heat-responsive genes were identified. Intriguingly, genes encoding chlorophyll a/b-binding proteins, WRKY transcription factors, and fatty acid desaturase were predominantly responsive during heat stress and appeared to regulate photosynthesis. In addition, a genome-wide scan of photosynthetic and sugar metabolic genes revealed reduced transcription levels for ribulose 1,5-bisphosphate carboxylase/oxygenase under heat stress, especially in CP, possibly attributable to elevated levels of soluble sugars. Conclusion: Our comprehensive genomic analysis reveals candidate loci/gene targets for breeding and functional studies related to developing high temperature-tolerant ginseng varieties.

Effects of induced heat stress on temperature response and biochemistry: alteration of biochemical constituents in Holstein calves by heat stress

  • Lim, Hyun-Joo;Ki, Kwang-Seok
    • Korean Journal of Agricultural Science
    • /
    • v.46 no.3
    • /
    • pp.637-643
    • /
    • 2019
  • The aim of the present study was to evaluate the effect of the induced heat stress on physiological response and serum biochemical parameters involving glucose, cholesterol, blood urea nitrogen (BUN), non-esterified fatty acids (NEFA), and cortisol in Holstein calves. Ten calves were kept in a climate controlled room (air temperature $37^{\circ}C$ and 90% humidity from 09:00 to 19:00) for three days. Those animals were given a one-day adaptation period. During the treatment period, we measured the skin temperature six times. Following the treatment periods, blood samples were collected before the experiment began (09:00) and at the end of the stress period (19:00). To aid analysis of the biochemical parameters, also we monitored the rectal temperature. The results, exhibited that both rectal and skin temperature showed increase in the heat stress-induced animals as compared with unstressed animals. Moreover, we noticed that the levels of BUN and NEFA increased in the blood serum of heat stress induced animals when compared with un-stressed ones. From these results, we concluded that the physiological and biochemical changes in the calves were induced by heat stress. Hence, the present study findings could be employed as base line data for development of stress reduction techniques in the dairy industry.

Comparison of Several Heat Stress Indices for the 2016 Heat Wave in Daegu (대구의 2016년 폭염시기 열 스트레스 지표의 비교)

  • Kim, Ji-Hye;Kim, Hae-Dong
    • Journal of Environmental Science International
    • /
    • v.26 no.12
    • /
    • pp.1399-1405
    • /
    • 2017
  • We compared the spatial distribution of several heat stress indices (the Wet-Bulb Globe Temperature(WBGT) index, Environmental Stress Index (ESI), and Modified Discomfort Index(MDI)) for the heat wave of June 6~August 26, 2016, in Daegu. We calculated the heat stress indices using data from the high density urban climate observation network in Daegu. The observation system was established in February. 2013. We used data from a total of 38 air temperature observation points (23 thermometers and 18 automatic weather stations). The values of the heat stress indices indicated that the danger level was very high from 0900-2000h in downtown Daegu. The daily maximum value of the WBGT was greater than or equal to $35^{\circ}C$. The differences in the heat stress indices from downtown and rural areas were higher in the daytime than at nighttime. The maximum difference was about 4 before and after 1400h, and the time variations of the heat stress indices corresponded well. Thus, we were able to confirm that the ESI and MDI can be substituted with the WBGT index.