• Title/Summary/Keyword: Heat stress indices

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Heat tolerance in Brazilian hair sheep

  • Seixas, Luiza;Melo, Cristiano Barros de;Tanure, Candice Bergmann;Peripolli, Vanessa;McManus, Concepta
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.4
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    • pp.593-601
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    • 2017
  • Objective: The aim of this study was to evaluate heat tolerance using heat tolerance indices, physiological, physical, thermographic, and hematological parameters in Santa Ines and Morada Nova sheep breeds in the Federal District, Brazil. Methods: Twenty-six adult hair sheep, one and a half years old, from two genetic groups (Santa Ines: 12 males and 4 females; Morada Nova: 7 males and 3 females) were used and data (rectal temperature, respiratory rate, heart rate, skin temperatures; hematological parameters) were collected during three consecutive days, twice a day (morning and afternoon), with a total of six repetitions. Also physical parameters (biometric measurements, skin and hair traits) and heat tolerance indices (temperature-humidity index, Iberia and Benezra) were evaluated. The analyses included analyses of variance, correlation, and principal components with a significance level of 5%. Results: The environmental indices, in general, indicate a situation of thermal discomfort for the animals during the afternoon. Breed significantly influenced (p<0.001) physiological and physical characteristics of skin, hair, biometric measurements and Iberia and Benezra heat tolerance indices. Santa Ines animals were bigger and had longer, greater number and darker hair, thicker skin, greater respiratory rate and Benezra index and lower Iberia index compared with Morada Nova breed. Conclusion: Although both breeds can be considered adapted to the environmental conditions of the region, Morada Nova breed is most suitable for farming in the Midwest region. The positive correlation found between the thermographic temperatures and physiological parameters indicates that this technique can be used to evaluate thermal comfort. Also, it has the advantage that animals do not have to be handled, which favors animal welfare.

Effects of Cadmium on Heat Shock Protein Induction and on Clinical Indices in Rats (카드뮴이 랫드의 Heat Shock Protein 발현에 미치는 영향과 독성학적 변화에 관한 연구)

  • 김판기
    • Journal of Environmental Health Sciences
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    • v.22 no.4
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    • pp.91-101
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    • 1996
  • Exposure indices are important tools which enable scientists to reliably predict and detect exposures to xenobiotics and resultant cell injury. Since the de novo synthesis of stress proteins can be detected early after exposure to some agents, analysis of toxicant-induced changes in gene expression, i.e. alterations in patterns of protein synthesis, may be useful to develop as biomarkers of exposure and toxicity. The acute and chronic effects of cadmium(Cd, $CdCl_2$ 20 mg/kg) on Wistar male rats were evaluated concerning cadmium contents, tissues enzyme activity, HSP expression. The results of the study were as follows: 1. Less cadmium was absorbed through the digestive tracts, but the ratio of contents in renal to hepatic cadmium was higher at 8 weeks after treatment. 2. ALT(alanine aminotransferase), AST(aspartate aminotransferase), glucose, BUN(blood urea nitrogen), creatinine, the key indices of the clinical changes in hepatic and renal function were significantly changed by the cadmium treatment after 1 week in liver, after 4 weeks in kidney. 3. Enhanced synthesis of 70 KDa relative molecular mass proteins were detected in 2 hours after cadmium exposure, with maximum activity occurring at 8~48 hours. Induction of $HSP_{70}$ was evident at proximal tubules and glomeruli in kidney. Testicular cells produced enough HSP to be detected normally. From the above results, it could be concluded that $HSP_{70}$ induction by the cadmium treatment was a rapid reaction to indicate the exposure of xenobiotics.

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A Study on the Plasma Biochemical Indices of Heat-Stressed Broilers

  • Lin, H.;Du, R.;Gu, X.H.;Li, F.C.;Zhang, Z.Y.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.9
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    • pp.1210-1218
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    • 2000
  • Four experiments were conducted to evaluate the effect of temperature and humidity on biochemical indices of Arbor Acres broilers at different weeks of age. The alkaline phosphatase (AKP), acid phosphatase (ACP), lactic dehydrogenase (LD), creatine kinase (CK), plasma glucose (Glu), calcium (Ca), potassium (K), chloride (Cl), urea nitrogen (UN), uric acid (UA), plasma thyroxin (T4), triiodothyronine (T3) and insulin levels were determined in all the four experiments. In experiment 1, the plasma Glu, LD and CK levels were increased by heat exposure ($35{^{\circ}C}$ and 35, 60, or 85% RH, 2 h) and this effect was aggravated by longer exposure (24 h). No significant changes (p>0.05) were found in Ca concentration, activity of AKP and ACP. In experiment 2, temperature (10, 20, 30, $33{^{\circ}C}$) had significant effect on the levels of K, Cl, UN, UA levels and the activity of LD (p<0.01), but had no significant influence on the activity of CK (p>0.05). The UN, UK and LD levels were elevated by low temperature $(10{^{\circ}C})$ (p<0.01), Cl content was increased by high temperature ($(33{^{\circ}C})$ (p<0.01), and K level was decreased by high ($(33{^{\circ}C})$ or low $(10{^{\circ}C})$ temperature and increased by medium temperature $(30{^{\circ}C})$ (p<0.01). The humidity (35, 85% RH) only had significant effect on Cl concentration which was decreased by high humidity (p<0.01). In experiment 3, the result showed that only the LD and CK activity were significantly increased (p<0.01) by high temperature (7, 24, 28, $32{^{\circ}C}$) or high humidity (35, 85% RH). Temperature and humidity had no significant effect on K, Cl, UA, UN and Glu levels (p>0.05). In experiment 4 (24, 27, 30, $33{^{\circ}C}$; 30, 45, 60, 75, 90% RH), plasma T3 level was declined by high temperature $(33{^{\circ}C})$, and this phenomena disappeared in birds under high temperature and high humidity environment. T4 concentration in plasma was not affected by temperature (p>0.05), but was increased by high or low humidity (p<0.01). Neither temperature nor humidity had significant effect on plasma insulin concentration (p>0.05). The results of the four experiments suggested that broilers at different growth periods might have different thermal requirements and would response differently to heat exposure. The plasma biochemical indices themselves had big variation; the reaction of the indices to thermal exposure treatment differed with the age of broilers. The big variation of biochemical indices themselves might cover the response of indices to temperature and humidity treatments.

Potentials of Phyllanthus amarus, Viscum album and Moringa oleifera supplements to mitigate heat stress in female rabbits in humid tropics

  • Olatunji Abubakar Jimoh;Blessing Oluwaseun Olakanye;Ayoola Mercy Ajewole;Saanu Olajumoke Akinbuyide;Johnson Sunday Adetifa;Abdul-Quadri Ayodeji Jimoh;Adewale Oluwatosin Mayowa;Feyisayo Pemisire Adesina
    • Journal of Animal Science and Technology
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    • v.66 no.1
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    • pp.79-92
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    • 2024
  • Global warming is a key challenge subjecting animals to heat stress conditions resulting in multiple physiological alterations in tropical climate. Dietary approach seems to be the more friendly approach to curb the adverse effects of heat stress in rabbits. Some herbs have been categorized to have high potential for promotion of immune responses for amelioration of heat stress. Thus, this research aims to evaluate the potential of Mistletoe (Viscum album), Moringa (Moringa oleifera) and Phyllanthus (Phyllanthus amarus) leaf meal as herbal supplements for the alleviation of heat stress in female rabbits by measuring improvement in sex and stress hormonal responses in serum biochemistry. 80 Rabbit does were exposed to 4 dietary groups supplemented with each of Mistletoe, Moringa, Phyllanthus and a control in an 84-day trial at the summit of thermal stress in South west Nigeria. Growth indices were monitored throughout the study, blood samples were compiled at the end of the trial to assess serum biochemistry, stress and sex hormonal responses of the Does using standard protocols. The results revealed that final weight and weight gain of Does fed on Phyllanthus were significantly (p < 0.05) higher (11.46% and 14.25%, respectively) than Does on control. The herbal supplements enhance glucose, protein, albumin and globulin, reduced cholesterol, and creatinine of Does under heat stress conditions. Among the herbal treatment groups, mistletoe, moringa and phyllanthus had 12.42%, 18.39% and 16.90%, respectively, lower corticosterone than control groups which had 39.76ng/ml. Triiodothyronine of Does fed control were significantly (p < 0.05) lower than Does on Moringa oleifera and Phyllanthus amarus supplements. Estradiol and Follicle stimulating hormone of rabbit Does fed on moringa supplement were significantly (p < 0.05) higher than other treatments. In conclusion, the herbal supplements tend to mitigate the detrimental outcome of thermal stress on Does by suppressing stress hormones. Moringa oleifera and Phyllanthus amarus enhanced sex hormones while Phyllanthus amarus confered growth promoting effects on the Does.

Lipid Metabolism and Peroxidation in Broiler Chicks under Chronic Heat Stress

  • Shim, K.S.;Hwang, K.T.;Son, M.W.;Park, Garng H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.8
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    • pp.1206-1211
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    • 2006
  • The effects of taurine supplementation on growth performance, serum and liver concentrations of lipid, fatty acid composition and lipid peroxidation in the livers of broilers under chronic heat exposure conditions were investigated. The chicks with a similar body weight were equally assigned to one of three controlled-environment chambers. The brolier chicks, which were kept at $34^{\circ}C$ were fed either with a control diet or the control diet supplemented with 0.8% taurine, whereas broiler chicks kept at $22^{\circ}C$ were fed a control diet. Both of the BW and BW gains of broilers maintained at a temperature of $34^{\circ}C$ were significantly lower than those of the control group, which was maintained at a temperature of $22^{\circ}C$ (p<0.05). However, taurine addition in the diet of birds submitted to heat stress siginficantly improved BW gain (p<0.05). The feed intake of chicks declined with increases in temperature. The relative liver and gall bladder weights of chicks fed the control diet and maintained at $34^{\circ}C$ were significantly lower than those measured in the control birds (p<0.05). However, dietary taurine was found to compensate for these reductions in liver and gall bladder weights. Relative weights of abdominal fat did not differ significantly among the three groups. Serum triglyceride concentrations were significantly lower in the chicks fed the control diet and maintained at $34^{\circ}C$ compare to those measured in the chicks fed the control diet at $22^{\circ}C$ (p<0.05). Heat stress resulted in a significant reduction in total lipid and triglyceride levels, but also increased the levels of total cholesterol in the liver (p<0.05). However, dietary taurine supplementation under the heat stress condition resulted in the recovery, to control levels, of serum triglyceride concentrations, as well as the amounts of total lipids, triglycerides, and cholesterol in the liver. The livers of chicks fed on taurine diets at $34^{\circ}C$ showed significantly higher proportions of C14:0, C16:1, C18:1, C18:2, and 20:3, and lower C18:0 and C20:4 proportions than those of chicks fed on control diets at the same temperature (p<0.05). The total levels of saturated fatty acids decreased, but monounsaturated fatty acids and unsaturated fatty acid levels increased in chicks fed the taurine diet, as compared to chicks fed the control diet at $34^{\circ}C$ (p<0.05). Peroxidizability indices were significantly lower in the heat-exposed chicks fed the taurine diet than in the non-taurine heat-exposed groups (p<0.05). In conclusion, dietary taurine results in an increase in the growth performances of chicks under heat stress conditions via improvements in lipid absorption and metabolism, as well as an induced reduction in lipid peroxidation.

Monitoring of Crop Water Stress with Temperature Conditions Using MTCI and CCI (가뭄과 폭염 조건에서 MTCI와 CCI를 이용한 수분 스트레스 평가)

  • Kyeong-Min Kim;Hyun-Dong Moon;Euni Jo;Bo-Kyeong Kim;Subin Choi;Yuhyeon Lee;Yuna Lee;Hoejeong Jeong;Jae-Hyun Ryu;Hoyong Ahn;Seongtae Lee;Jaeil Cho
    • Korean Journal of Remote Sensing
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    • v.39 no.6_1
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    • pp.1225-1234
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    • 2023
  • The intensity of crop water stress caused by moisture deficit is affected by growth and heat conditions. For more accurate detection of crop water stress state using remote sensing techniques, it is necessary to select vegetation indices sensitive to crop response and to understand their changes considering not only soil moisture deficit but also heat conditions. In this study, we measured the MERIS terrestrial chlorophyll index (MTCI) and chlorophyll/carotenoid index (CCI) under drought and heat wave conditions. The MTCI, sensitive to chlorophyll concentration, sensitively decreased on non-irrigation conditions and the degree was larger with heat waves. On the other hand, the CCI, correlated with photosynthesis efficiency, showed less sensitivity to water deficit but had decreased significantly with heat waves. After re-irrigation, the MTCI was increased than before damage and CCI became more sensitive to heat stress. These results are expected to contribute to evaluating the intensity of crop water stress through remote sensing techniques.

Functional Characterization of Mammary Gland of Holstein Cows under Humid Tropical Summer Climates

  • Lu, C.H.;Chang, C.J.;Lee, P.N.;Wu, C.P.;Chen, M.T.;Zhao, X.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.7
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    • pp.988-995
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    • 2003
  • Physiological parameters were measured on six primiparous, non-pregnant Holstein cows prior to peak lactation over a 3-month summer season in southwestern Taiwan. The objectives were to characterize heat stress-induced change in functionality of mammary gland under natural climates of tropical summer and to establish physiological indices applicable to this environment in referring to this change. Environmental and physiological readings, milk and blood samples were taken at 15:00 h biweekly for totally five time points during the study. Climate readings showed that the afternoon humidex value reached the highest (53.5) around mid summer. Rectal temperature of cows taken simultaneously varied between $38.26^{\circ}C$ and $40.02^{\circ}C$ in parallel to humidex. Milk production declined drastically from 29.2 to 22.2 kg/d the first month entering summer but leveled up at end of the summer season suggesting effects exerted by heat stress rather than stages of lactation. Lactose content decreased linearly (p<0.05) with times in summer, from 4.69 to 4.38%. On the other hand, activity of N-acetylglucosaminidase (NAGase) in milk increased linearly to over two folds (p<0.05) during the same intervals. Elevations of fractional constituent of BSA in whey protein and serum cortisol level were also noticed in the course. Measurement of arteriovenous concentration (A-V) difference across the mammary gland demonstrated net uptake of glucose and net release of urea throughout the study period. The amount of urea released from mammary gland increased (p<0.05) progressively from 1.54 to 7.76 mg/dl during summer. It is concluded that gradual regression of mammary gland occurred along the humid tropical summer season. This regression is likely initiated through elevation of body temperature, which is irreversible above certain point. The increased release of urea from mammary gland during heat stress suggests its potential role as an early indicator of suboptimal mammary function.

Thermal Environment Transition of Response Climate Change and Heat Wave Application Evaporative Cooling System (기후변화 및 폭염대응 증발냉각시스템 적용에 따른 내·외부 열환경 변화 연구)

  • Kim, Jeong-Ho;Kim, Hak-Gi;Yoon, Yong-Han;Kwon, Ki-Uk
    • Journal of Environmental Science International
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    • v.25 no.9
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    • pp.1269-1281
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    • 2016
  • This study evaporative cooling system a heat wave climate change and reduction of the inside and outside thermal environment change research. Measurement items included micro meteorological phenomena and measured comfort indices. A micro meteorograph of temperature, relative humidity, surface temperature, and the comfort indices of WBGT, UTCI, and PMV were measured. The difference in inside and outside temperatures were compared for different land types, with the largest difference found in Type A ($4.81^{\circ}C$), followed by Type B ($4.40^{\circ}C$) and Type C ($3.12^{\circ}C$). Relative humidity was about 10.43% higher inside due to water injection by the evaporative cooling system. Surface temperature was inside about $6.60^{\circ}C$ higher than the outside all types. WBGT were Type A ($3.50^{\circ}C$) > Type B ($2.71^{\circ}C$) > Type C ($1.88^{\circ}C$). UTCI was low heat stress inside than outside all types. PMV was analysed Type C for inside predicted percentage of dissatisfied 75%, other types was percentage of dissatisfied 100% by inside and outside. Correlation analysis between land cover type and temperature, surface temperature, pmv, utci. T-test analysed inside and outside temperature difference was significant in all types of land.

Characteristics of Thermal Variations with the Different Land Covers in an Urban Area (도시 지역에서 토지 피복에 따른 열 변이 특성)

  • Park, Sung-Ae;Kong, Hak-Yang;Kim, Seung-Hyun;Park, Sungmin;Shin, Young-Kyu
    • Ecology and Resilient Infrastructure
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    • v.3 no.1
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    • pp.46-53
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    • 2016
  • This study was conducted to analyze the effect of the different land covers of an urban park (Hyowon park) in downtown Suwon on the urban thermal variations during a hot summer. The effect of the air temperature reduction in the urban park was 4.4%-4.5% for the downtown residence (Maetan-dong). This value was about 0.8% lower than that of the outskirts residence (Sanggwanggyo-dong). The daily mean temperature, daily maximum temperature, summer day and heat wave frequency were measured under the different land covers (cement-block, grass, pine-grass, shading area and mixed forest) showed these values generally decreased under natural land cover types. Daily minimum temperature and tropical night frequency didn't seem to correlate with the land cover types. Means of thermal comfort indices (wet bulb globe temperature, heat index and discomfort index) in the shading area, mixed forest and the pine-grass types were lower than those of cement block and grass types. However the levels of those indices were equal to 'very high' or 'caution' levels in the afternoon (13:00-15:00). In the morning (06:00-08:00), thermal comfort indices of the urban park didn't correlate with land cover types. Therefore, to reduce heat stress and to improve the thermal comfort in urban parks, an increase in the area of natural land cover such as grass, forest and open spaces is required.

A Study on the Absorption of Thermal Stress on the Underground piping for the District heating (지역난방용 매설배관의 열응력 흡수에 관한 연구)

  • Kong Jae Hyang;Sin Byung Kug
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.14 no.1
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    • pp.81-88
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    • 2005
  • There have been many studies on generation equipment and plant piping, but there is no significant study result on the heat transportation pipe. As such, this study established basic theory on the compensated method among buried pipe for regional heating, and further obtained the following results by applying the conditions of AGFW and NCHPP respectively in calculation of friction and maximum installation distance for the buried pipe. Friction coefficient according to the types and physical properties of soil, friction and maximum installation distance were compared to set the application value of friction coefficient according to the location of works. Calculation formula of clay load to be applied for calculation of friction was introduced to the formula of AGFW and the formula of NCHPP that has been used in Nowon district since 1997 to determine the difference and applicability. $120^{\circ}C$ and $95^{\circ}C$ were applied in temperature difference for expansion volume to compare the arm length at the curve pipe so thai it can be reflected in the design in the future. Maximum installation distance according to thickness of pipe was compared to present the necessity of unified specification so that same kinds of pipe materials can be used for same kinds of works.