Impact Of Heat Stress Research Articles

Vitamin C Alleviates Heat-Stress-Induced Damages in Pig Thoracic Vertebral Chondrocytes via the Ubiquitin-Mediated Proteolysis Pathway

Heat stress can impair organismal growth by inducing ubiquitination, proteasome-mediated degradation, and subsequent cellular damage. Vitamin C (VC) has been shown to potentially mitigate the detrimental effects of abiotic stresses on cells. Nevertheless, the impact of heat stress on growth plate chondrocytes remains unclear, and the underlying protective mechanisms of VC in these cells warrant further investigation. In this study, we focused on pig thoracic vertebral chondrocytes (PTVCs) that are crucial for promoting the body’s longitudinal elongation and treated them with 41 °C heat stress for 24 h, under varying concentrations of VC. Our findings reveal that, while oxidative stress induced by heat triggers apoptosis and inhibits the ubiquitin-mediated proteolysis pathway, the addition of VC alleviates heat-stress-induced oxidative stress and apoptosis, mitigates cell cycle arrest, and promotes cellular viability. Furthermore, we demonstrate that VC enhances the ubiquitin-proteasome proteolysis pathway by promoting the expression of ubiquitin protein ligase E3A, which thereby stabilizes the ubiquitin-mediated degradation machinery, alleviates the apoptosis, and enhances cell proliferation. Our results suggest the involvement of the ubiquitin-mediated proteolysis pathway in the effects of VC on PTVCs under heat stress, and offer a potential strategy to make use of VC to ensure the skeletal growth of animals under high temperature pressures in summer or in tropical regions.

Impact of Heat Stress on Individual Cognitive States: Utilizing EEG Metrics in Immersive VR–Based Construction Safety Training

Impact of Heat Stress on Individual Cognitive States: Utilizing EEG Metrics in Immersive VR–Based Construction Safety Training

Drought and heat stress interactions: Unveiling the molecular and physiological responses of Persian walnut

While numerous studies explored the response of walnut plants to drought stress (DS), there remains a significant gap in the knowledge regarding the impact of heat stress (HS) and the combined effects of DS and HS on the recovery capacity of walnut trees. This study aimed to investigate the mechanism of Persian walnut (cv. Chandler) response to the combined DS and HS, focusing on various aspects including photosynthesis, water relations, and osmotic regulation. The treatments involved subjecting plants to DS (through a withholding method for 24 d), HS (gradually up to 40 °C for 8 d), and a combined DS and HS, which were compared to a control group (no stress) during the stress and recovery phases. The results showed that DS had significantly more negative effects on chlorophyll content, relative water content (RWC), leaf water potential (WP), osmotic potential (OP) compared to HS. Involvement of osmoregulation mechanism was detected more in DS and HS plants through the accumulation of proline, glycine Betaine and total soluble carbohydrates. The functionality of photosynthesis was significantly impacted by both HS and DS, respectively. While the HS accelerated the change of the abovementioned physiological processes in drought-stressed seedlings. Consistently, more pronounced damage was found in leaves under the combined stress, alongside the decrease RWC, chlorophyll content and fluorescence ratios. Based on the analysis of the linear mixed-effect model, the effects of combined stress and HS on photosynthesis parameters were detected in the early stages of stress compared to DS. Within a range of stresses, the abovementioned physiological processes of individual and combined-stressed plants recovered to levels comparable to those of the control. Our results also showed a substantial reduction in the expression of the photosynthetic genes (Fd, Cyt b6f, and PsbB) in Persian walnut saplings under abiotic stress conditions indicating significant damage to their photosynthetic apparatus. This study highlights that, under scenarios of aggravating drought occurring with heat, walnut seedlings could face a high risk of damage to physiological structures in relation to the synergistically increased hydraulic and thermal impairments.

The Impact of Climate Variability on Cattle Heat Stress in Vanuatu

Heat stress is a climate extreme that impacts cattle health, fertility, feed intake, production, and well-being. In Vanuatu, the beef industry is crucial to local livelihoods and the nation’s economy, thus the objective of this study was to examine the impact of heat stress on cattle health and production. This study uses the Heat Load Index (HLI) and Accumulated Heat Load (AHL) as proxies to assess the impact of heat stress on cattle in Vanuatu over a 30-year period (1994–2023), using the fifth generation of the European Centre for Medium-Range Weather Forecasts (ECMWF) atmospheric reanalysis of the global climate (ERA5) data. The analysis examines historical patterns of heat stress in cattle across Vanuatu, identifying more instances of heat stress occurring during the wet season due to characteristically elevated temperatures, humidity, and low wind speeds. Findings also suggest that El Niño events may increase the intensity and duration of heat stress events. These insights inform the development of an Early Warning System for heat stress in cattle, establishing a crucial foundation for targeted adaptation strategies aimed at enhancing the resilience and sustainability of Vanuatu’s beef industry to climate variability and change.

Effects of Whole Flaxseed in Reduced Energy Diets on Broiler Chickens Meat Quality and Carcass Characteristics Under Heat Stress Condition

This study aimed to assess the impact of heat stress (HS) on broiler chickens provided with a low-energy diet including whole flaxseed, focusing on carcass characteristics and meat quality. A total of 250 one-day-old Ross 308 broiler chicks were randomly allocated into five groups (50 chicks per group), with two replicates for each group. The negative control treatment (T1) received a basal diet devoid of HS. The second treatment fed a basal diet under HS as a positive control (T2). In the third experiment, they fed a basal diet, including whole flaxseed, under heat-stress conditions (T3). The fourth treatment consisted of providing a low-energy diet with whole flaxseed under HS (T4). The fifth intervention was a reduced energy diet administered under HS (T5). The carcass characteristics and edible entrails in the T3 and T4 groups showed a significant improvement (P≤0.05) compared to the control groups. The meat quality in the T3 and T4 groups was considerably enhanced (P≤0.05) due to an increase in omega-3 fatty acid levels [α-linolenic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA)], as determined by GC mass spectrometry compared to the control group that had a corn-soybean diet. In conclusion, incorporating whole flaxseeds into a low-energy diet during HS augmented broiler chickens’ productivity, improved carcass characteristics, and elevated omega-3 concentrations in the meat.

Study protocol for an observational cohort study of heat stress impacts in pregnancy in The Gambia, West Africa

Climate change has resulted in an increase in heat exposure globally. There is strong evidence that this increased heat stress is associated with poor maternal and fetal outcomes, especially in vulnerable populations. However, there remains poor understanding of the biological pathways and mechanisms involved in the impact of heat in pregnancy. This observational cohort study of 764 pregnant participants based in sub-Saharan Africa, a geographical region at risk of extreme heat events, aims to evaluate the physiological and biochemical changes that occur in pregnancy due to heat stress. The key objectives of the study are to 1) map exposure to heat stress in the cohort and understand what environmental, social and community factors increase the risk of extreme heat exposure; 2) assess the impact of heat stress on maternal health, e.g. heat strain, subjective psychological well-being, sleep and activity level; 3) evaluate how heat stress impacts placenta structure and function; 4) determine how chronic heat exposure impacts birth outcomes; and 5) explore the epigenetic changes in the placenta and infant by heat stress exposure per trimester. Pregnant women will be recruited from two distinct regions in The Gambia to exploit the naturally occurring heat gradient across the country. Microclimate mapping of the area of recruitment will give detailed exposure measurements. Participants will be asked to wear a watch-style device at 28- and 35-weeks gestational age to evaluate maternal heart rate, activity and sleep. At the end of the week, an ultrasound scan will be performed to evaluate fetal size and placental blood flow. At delivery, birth outcomes will be recorded and maternal, placental and cord samples taken for epigenetic, biochemical and histological evaluation. Evaluation of neuro-behaviour and final infant samples will be taken at 1 month following birth.

Nitric oxide: Potential therapeutic target in Heat Stress-induced Multiple Organ Dysfunction.

As climate change intensifies, urgent action is needed to address global warming and its associated health risks, particularly in vulnerable regions. Rising global temperature and increasing frequency of heatwaves present a hidden health risk, disrupting the body's temperature regulation and leading to severe consequences such as heat stress-induced multiple organ dysfunction (HS-MOD). Multiple organ injury triggered by heat stress involves complex molecular pathways such as nitric oxide dysregulation, inflammation, oxidative stress, mitochondrial dysfunction, calcium homeostasis disruption, and autophagy impairment that contribute to cellular damage. Understanding these molecular pathways is crucial for developing targeted therapeutic interventions to alleviate the impact of heat stress (HS). As we explore numerous therapeutic strategies, a remarkable molecule captures our attention: nitric oxide (NO). This colorless gas, mainly produced by nitric oxide synthase (NOS) enzymes, plays crucial roles in various body functions. From promoting vasodilation and neurotransmission to regulating the immune response, platelet function, cell signaling, and reproductive health, NO stands out for its versatility. Exploring it as a promising treatment for heat stress-induced multiple organ injury highlights its distinctive features in the journey towards effective therapeutic interventions. This involves exploring both pharmacological avenues, considering the use of NO donors and antioxidants, and non-pharmacological strategies, such as adopting nitrate-rich diets and engaging in exercise regimens. This review highlights the concept of heat stress, the molecular framework of the disease, and treatment options based upon some new interventions.

Differential expression of hemolymph proteins in wild bumblebees provides insights into species‐specific impacts of heat stress

AbstractWildlife faces an increasing threat from extreme climatic events, such as heatwaves, which can have a severe impact on various species, including crucial pollinators like bumblebees. Bumblebees are cold‐adapted and heterothermic, possessing the ability to regulate their internal temperature. The impact of heat stress seems species specific in bumblebees. While most species are impacted, some bumblebee species manage to survive, potentially by employing physiological mechanisms, including the modulation of their protein profile (e.g. Heat Shock Proteins). However, there is limited understanding of how their protein profiles are associated with heat exposure. In this study, we examined the global variation in the protein profile of males from two bumblebee species sampled in the wild: the heat‐tolerant Bombus terrestris and the heat‐sensitive Bombus magnus. After subjecting them to heat stupor at 40°C in controlled condition, it was observed that nearly all B. terrestris survived the stress, while over 50% of B. magnus individuals succumbed to the heat exposure. Through off‐gel bottom‐up proteomics and LC–MS/MS analysis of the hemolymph proteome, we identified 164 proteins in both species with a large part of differentially expressed proteins after heat exposure. Additionally, quantitative analysis of fat bodies revealed that the relative mass was stable in B. terrestris, while it was significantly lower in B. magnus exposed to heat stress. Our data suggest that compared with B. magnus, B. terrestris displays a higher adaptability of its hemolymph proteome in response to heat stress. This adaptability could be a key factor contributing to the high physiological resistance of B. terrestris and its ability to adapt to new, stressful environments expected due to climate change. Understanding these mechanisms of protein regulation in bumblebees could provide valuable insights into their resilience and vulnerability facing environmental stresses.

Mid infrared spectroscopy combined with chemometrics as tool to monitor the impact of heat stress and dietary interventions in lactating sows.

Heat stress in hyper-prolific lactating sows is recognised as a factor reducing feed intake, milk production, and welfare, with significant losses in farm productivity. Individual capacities for body thermoregulation during environmental hyperthermia determine the adaptation of the animal during long and recurrent events. This study aimed to evaluate the ability of attenuated total reflectance (ATR) mid infrared (MIR) spectroscopy as a high-throughput method to identify markers of stress in plasma and milk collected from lactating sows under heat stress conditions fed with two levels of protein in the diet defined as low (16%) and standard (20%). The MIR spectra were analysed using linear discriminant analysis (LDA) and principal component analysis and validated using cross-validation. The results obtained indicated that MIR spectroscopy, in combination with chemometrics, was able to identify changes in the spectra associated with heat stress in wavenumbers corresponding with amide groups (proteins) (highest loadings observed in the regions between1065 and 1635cm-1), lipids and unsaturated fatty acids (regions between 1746 and 3063cm-1), lipo-polysaccharides (in 1247cm-1) and carbohydrates (around the region1050 cm-1). These results also indicated that the information provided by these wavenumbers can be used as metabolic markers of the adaptation of the sows to hyperthermia. It was concluded that MIR spectroscopy is a rapid and inexpensive tool capable of detecting and evaluating the main biochemical changes of hyperthermia on lactating sows, facilitating the development of palliative management strategies such as dietary manipulations.

Impact of heat stress on poultry production: Feed intake, water homeostasis, gut integrity, and meat quality

Heat stress (HS) is a major challenge to the poultry industry, especially as global temperatures continue to rise due to climate change. Heat stress has a negative effect on poultry by disrupting production sustainability, water homeostasis, gut integrity, and meat quality, leading to economic losses and welfare concerns. This review consolidates current research on these issues and explores potential strategies to mitigate the adverse effects of HS. Nutritional interventions, environmental modifications, e.g., ventilation systems and cooling techniques, as well as genetic approaches are discussed as promising solutions to improve poultry resilience to HS. Moreover, this article emphasizes the importance of adopting sustainable and innovative practices to enhance poultry farming’s long-term viability, ensuring that production systems remain both efficient and environmentally friendly. As climate change continues to intensify, the development of holistic and effective solutions becomes critical to support the global poultry industry and meet the growing demand for high-quality protein sources in a sustainable manner.

Heat stress: a major threat to ruminant reproduction and mitigating strategies.

Stress is an external event or condition that puts pressure on a biological system. Heat stress is defined as the combination of internal and external factors acting on an animal to cause an increase in body temperature and elicit a physiological response. Heat stress is a set of conditions caused by overexposure to or overexertion at excess ambient temperature and leads to the inability of animals to dissipate enough heat to sustain homeostasis. Heat exhaustion, heat stroke, and cramps are among the symptoms. For the majority of mammalian species, including ruminants, heat stress has a negative impact on physiological, reproductive, and nutritional requirements. Reproductive functions, including the male and female reproductive systems, are negatively affected by heat stress. It decreases libido and spermatogenic activity in males and negatively affects follicle development, oogenesis, oocyte maturation, fertilization, implantation, and embryo-fetal development in females. These effects lead to a decrease in the rate of reproduction and financial losses for the livestock industry. Understanding the impact of heat stress on reproductive tissues will aid in the development of strategies for preventing heat stress and improving reproductive functions. Modification of the microenvironment, nutritional control, genetic development of heat-tolerant breeds, hormonal treatment, estrous synchronization, timed artificial insemination, and embryo transfer are among the strategies used to reduce the detrimental effects of heat stress on reproduction. These strategies may also increase the likelihood of establishing pregnancy in farm animals.

Impact of Heat Stress on Milk Yield, Milk Fat-to-Protein Ratio, and Conception Rate in Thai-Holstein Dairy Cattle: A Phenotypic and Genetic Perspective.

Heat stress severely affects dairy cattle production and reproduction performances in tropical regions. Genetic selection to maintain adequate yield and reproductive performance while enhancing their ability to withstand heat is essential for improving the genetics of dairy cows. Therefore, in this study, we aimed to estimate genetic parameters affecting production and reproduction performances under heat stress conditions in dairy cattle and to investigate the threshold point of heat stress for milk yield (MY), milk fat-to-protein ratio (FPR), and conception rate (CR) in Thai-Holstein dairy cattle. The data included 168,124 records related to MY and milk FPR and 21,278 records of CR in Thai-Holstein dairy cattle, covering the period from 1990 to 2007. A multiple-trait threshold-linear random regression model based on a Bayesian approach via Gibbs sampling was used to estimate variance components, genetic parameters (heritability values, and genetic correlations), and decline rates for each studied trait. The threshold point of heat stress was identified as a temperature and humidity index (THI) of 76. At THI76, a decline was observed in the MY, milk FPR, and CR of Thai dairy cattle. The heritability estimates for MY, milk FPR and CR were 0.347 ± 0.032, 0.293 ± 0.021, and 0.032 ± 0.001, respectively. The genetic correlation between MY and milk FPR and MY and CR were -0.24 and -0.53, respectively, whereas those between milk FPR and heat tolerance as well as between CR and heat tolerance were -0.48 and -0.49, respectively. In addition, the decline rates in MY, milk FPR, and CR were found to be associated with a high percentage of Holstein genetics. In conclusion, the results obtained in this study reveal that the simultaneous consideration of the MY, milk FPR, CR, and heat tolerance traits of Thai-Holstein dairy cattle is possible. In addition, developing a genetic model that incorporates THI is essential for sustainably addressing heat stress problems.

Impact of temperature humidity index (THI) on blood gas and electrolytes of dairy cows in late gestation

The study was carried out to assess the impact of heat stress on dairy cows in late gestation and their newborn calves. Study was conducted in two phases in crossbred cattle during last trimester of pregnancy, maintained in University Livestock Farm and Fodder Research Development Scheme, Mannuthy, KVASU. December to February with minimum THI was taken as season 1 and March to May with maximum THI as season 2 of the study. Microclimatic data in the animal shed was recorded three times at three days intervals. The ambient temperature, relative humidity and THI obtained during season 2 was significantly (p<0.01) higher than season 1 in both macro and microclimatic data. Partial pressure of carbon dioxide (pCO2 ) was low in season 2 but there was no significant difference in potassium (K+), sodium (Na+), bicarbonate (HCO3 - ) and partial pressure of oxygen (pO2 ) between the seasons. Keywords: Heat stress in cattle, THI, blood gases, electrolytes, late gestation

The Relationship between the Infrared Eye Temperature of Beef Cattle and Associated Biological Responses at High Environmental Temperatures.

Cattle in regions with high ambient temperatures are at risk of heat stress. Early detection is important to allow action to be taken to minimise the risks to cattle exposed to thermal stress. This study aimed to investigate the impact of heat stress on IRT-Eye temperature and its association with the behavioural and physiological responses of heat-stressed Angus steers (n = 24) on finisher and or substituted diets. Overall, 2 cohorts of 12 Angus steers were individually housed in a climate-controlled facility to examine responses to heat stress when fed on a standard finisher diet, based on a high percentage of cereal grains, and on a substituted diet in which 8% of the grains were replaced by an isoenergetic amount of lucerne hay. Exposing feedlot cattle to hot environmental conditions increased IRT-Eye temperature, which had a strong association with behaviour and physiology. There was no evidence of differences between the different dietary cohorts. The cattle with increased IRT-Eye temperature showed stress-related responses, including a downward-facing head, ears directed backwards, and other indicators of heat stress such as increased panting, standing, and increased rumen temperature. The strong association of IRT-Eye temperature with stress-related behaviours, as well as with rumen temperature and panting behaviour, highlights the potential for IRT-Eye to be utilised as a non-invasive tool to assess cattle responses in hot conditions.

Minor Modification in Asbestos Roof of Cow Shed for Reduction of Heat Stress in Dairy Cows during Summer Season

Thermo neutral zone (TNZ) is the range of ambient temperature & humidity in which animals feel comfortable and their production level is optimum. When temperature humidity index (THI) goes above 72, the dairy cows begin to show symptoms of mild heat stress, which affects the milk production in dairy animals during summer season in India. Asbestos and GI sheet are commonly used as roofing material in many cattle farms throughout the world. This experiment was carried out on apparently healthy cross bred jersey cows receiving balanced ration during the month of May in the livestock farm of OUAT, Bhubaneswar for one week. The existing cattle shed was partitioned into three compartments by raising brick walls, each having the dimension of 30 x 25 ft size. The asbestos roof of first one was covered with 90 % grade green shed-net. Over the asbestos roof of second compartment, heat reflective white colour was painted and asbestos roof of third one was left as such. From 8.00 AM to 5.00PM, the THI of the normal asbestos roof shed varied from mild to moderate heat stress range. But THI of both shed-net covered shed and heat reflective colour painted shed was found to be within the mild heat stress range i.e. 72-79 during noon indicating a comfortable ambient condition for the animals in summer season when the outside ambient temperature went up to 40 0C during noon. No significant (P>0.05) change in the milk production was observed among the groups during the week. However, a decrease (P<0.05) of 0.43, 0.25 and 0.38 L in milk yield of the cows was observed when they were kept under normal asbestos shed, heat reflective colour painted shed and shed-net covered shed, respectively. From the study, this can be concluded that the impact of heat stress on milk production can be reduced by painting the rood of the shed with heat reflective colour paint.

Heat Stress in Beef Cattle: Climate Change and the Global Scenario – A Review

Abstract With the increasing human population and urbanization, the demand for animal origin products is going to grow, especially in the developing nations till the 2050s and the production needs to be escalated and optimized with the changing climate. Heat stress is known to reduce the animal performance, production, shelf life and meat quality in all animals. The beef cattle are globally reared, following different managemental practices, so the usage of natural resources like land and water, manpower, fodders, production systems and the environmental impact also varies profoundly. Recent changes in the climate, global warming and depletion of resources have severely affected the production and heat stress is now a common constraint all over the world. Due to evolutionary diversification the tropical and temperate breeds are comparatively more thermotolerant, but the beef cattle in the colder regions are vulnerable to high environmental temperatures. Also, the production of beef increases the carbon footprint and is much less eco-friendly than growing plant-based protein. So, we comprehended the environmental temperature variation over the continents and impact of heat stress on beef cattle. Also, other factors like cattle population, land and pasture usage, livestock units in trade, methane emissions and gross beef production value were examined to evaluate the collective impact of all these on the beef sector. Our findings and predictions reveal that, in the advent of climate change, depleting natural resources and rise in the greenhouse gases, beef production will be a constant challenge, which can be only achieved by maintaining a healthy cattle population and optimum usage of natural resources. Only then can the beef sector be efficient, sustainable, and a profitable enterprise in future.

Sex Differences in the Impact of Heat Stress on Kidney Function in a Large Taiwanese Population Study

Sex Differences in the Impact of Heat Stress on Kidney Function in a Large Taiwanese Population Study

Impact of heat stress on physiological characteristics and expression of heat shock proteins (HSPs) in groundnut (Arachis hypogaea L.).

The online version contains supplementary material available at 10.1007/s12298-024-01520-y.

Impact of heat stress on female reproduction in farm animals: challenges and possible remedies

Global warming poses significant challenges to agriculture, particularly within the livestock industry. Heat stress in animals refers to the physiological and metabolic distress experienced when environmental heat causes an animal’s body temperature to exceed its thermoneutral zone. Heat stress has a significant detrimental impact on reproductive outcomes, posing a direct threat to the profitability of livestock operations. Heat stress disrupts the normal hormonal balance essential for reproduction in female livestock, adversely affecting events of folliculogenesis and embryogenesis. As a result, the developmental competence of oocytes is compromised, which is crucial for successful fertilization and reproduction. Consequently, heat stress can lead to issues such as immature oocytes, atypical or sluggish embryonic development, silent estrus, and increased pregnancy loss causing a decline in reproductive rates and livestock owners face substantial financial losses. Despite using various cooling strategies, such as water sprinkler systems, cooling shades, and cooling devices, these measures are often insufficient to restore normal reproductive rates. Therefore, it is crucial to implement and explore novel strategies to enhance reproductive efficiency during periods of heat stress. Potential mitigation techniques include estrus synchronization, artificial insemination, hormonal alterations, embryo transfer, genetic engineering, sophisticated breeding strategies, the use of nutraceuticals, and changes in management practices. This review aims to consolidate recent findings on the adverse effects of heat stress on female reproduction, especially in tropical environments, and to evaluate potential strategies for improving summer fertility of livestock. Bangladesh Journal of Animal Science 53(3): 77-100, 2024

Impact and tolerance mechanism of heat stress in wheat (Triticum aestivum L.): A review

Wheat is one of the major cereal crops preferred by world’s population. About 55% of world’s population depend on wheat to meet their 20% calorie requirement. Wheat being a winter crop grows best in 15-25 degree Celsius of temperature range. But due to increasing global warming climatic requirement of wheat is not fulfilled and suffer different abiotic stresses such as heat, drought, salinity, cold, excess water etc. Among which heat stress is one of the major abiotic stresses faced by wheat. It has different morphological, biochemical and physiological consequences on wheat for instance poor grain quality, decreased grain number and weight, decreased photosynthesis due to disruption in chlorophyll structure and function, reduced starch content due to poor efficiency of enzyme required in biosynthesis. To cope up with all these impacts of heat stress wheat has developed various tolerance mechanisms such as release of heat shock protein, antioxidant defense mechanism, membrane thermostability, stay green, omics approaches etc. Heat shock protein helps to prevent death of cell, accumulation of denatured protein, refolding of protein, transmission of heat shock responses etc. While omics approaches help in gene profiling, protein identification etc. knowledge about both the effect and tolerance mechanism of heat stress in wheat helps to develop heat tolerant varieties with collaborative effort of plant breeder, physiologist etc. that helps to maintain food security.