Mitigate Heat Stress Research Articles

Minimal Yet Powerful: The Role of Archaeal Small Heat Shock Proteins in Maintaining Protein Homeostasis.

Small heat shock proteins (sHsp) are a ubiquitous group of ATP-independent chaperones found in all three domains of life. Although sHsps in bacteria and eukaryotes have been studied extensively, little information was available on their archaeal homologs until recently. Interestingly, archaeal heat shock machinery is strikingly simplified, offering a minimal repertoire of heat shock proteins to mitigate heat stress. sHsps play a crucial role in preventing protein aggregation and holding unfolded protein substrates in a folding-competent form. Besides protein aggregation protection, archaeal sHsps have been shown recently to stabilize membranes and contribute to transferring captured substrate proteins to chaperonin for refolding. Furthermore, recent studies on archaeal sHsps have shown that environment-induced oligomeric plasticity plays a crucial role in maintaining their functional form. Despite being prokaryotes, the archaeal heat shock protein repository shares several features with its highly sophisticated eukaryotic counterpart. The minimal nature of the archaeal heat shock protein repository offers ample scope to explore the function and regulation of heat shock protein(s) to shed light on their evolution. Moreover, similar structural dynamics of archaeal and human sHsps have made the former an excellent system to study different chaperonopathies since archaeal sHsps are more stable under in vitro experiments.

Public perceptions of potential adaptations for mitigating heat stress on Australian dairy farms

Temperature variability resulting from climate change poses challenges around the world for livestock production and the welfare of the animals in these systems. As animal industries attempt to combat these challenges, it is vital to understand how potential changes implemented by farmers resonate with societal values. The aims of this study were to determine how different proposed changes to mitigate heat stress in dairy cattle influence public perceptions toward Australian dairy farm systems, including perceptions of (1) cow welfare, (2) confidence in the industry, and (3) trust in farmers. Participants were presented with 1 of 4 treatments representing a potential solution to mitigate heat stress in dairy cattle: (1) indoor system (a fully indoor barn), (2) choice system (cows have agency to choose to be indoors or outdoors), (3) gene edition + pasture (cows are genetically modified to become more resilient to heat stress), and (4) pasture (outdoor system that is currently used in Australia, but the farmer plants more trees). Participants were then asked to respond to questions on a 7-point Likert scale. Questions were about cow welfare (3 questions), confidence in dairy industry (4 questions), and trust in farmers (9 questions), with each section followed by an open-ended question for participants to explain their answers. Participants perceived cow welfare to be the lowest in the indoor system (2.80 ± 0.10), followed by gene edition + pasture (4.48 ± 0.11), with choice and pasture systems being the highest but not different from each other (5.41 ± 0.11 and 5.32 ± 0.11, respectively). Confidence in the dairy industry was lower among participants in the indoor (4.78 ± 0.08) compared with participants assigned to the choice (5.28 ± 0.08) or pasture (5.25 ± 0.08) systems. Confidence was also lower among participants in the gene edition (4.95 ± 0.08) compared with the choice system. Trust in farmers was similar across all treatments. Our results provide the first evidence that the Australian public may be reluctant to accept heat stress mitigation strategies that either do not allow cows to have access to pasture or those that include gene-editing technologies.

Using of blue green algae extract and salicylic acid to mitigate heat stress on roselle (Hibiscus sabdariffa L.) plant under Siwa Oasis conditions

Increasing temperature is a global issue due to the existing climate change problem that reduces agricultural productivity and increases prices. It badly affects the yield, and active constituents of medicinal and aromatic plants, especially in newly reclaimed lands in desert areas. The Hibiscus sabdariffa L. is a remarkable crop known for its calyces to make a refreshing drink. It is in other food industries and has many healing effects. A split-plot field experiment was conducted on Hibiscus sabdariffa L. at Siwa Oasis, Egypt, during the 2018 and 2019 seasons for studying to reduce the harmful effect of heat stress on plants and yield improvement. Spraying with three salicylic acid concentrations was put to main plots as 0, 500, and 1000 mg/l and the number of sprays with Spirulina platensis algae extract was allotted to sub-plots and used as 0, 1 and 2 times in the season. Some quantity and quality parameters were under investigation. The significant highest increases in dry weight per plant, number of fruits per plant, dry yield of sepals per hectare and sepal's anthocyanin content were from the combination among spraying with salicylic acid at the concentration of 500 mg/l and spraying with blue green algae extract twice through the season. This treatment was helpful to decrease the high-temperature injury on growth through the summer months.

192 Engineering Strategies and Solutions to Improve Swine Resilience and Alleviate Physiological Stress in a Changing Climate

Abstract Heat stress negatively affects a variety of production parameters in the swine industry including growth, carcass composition, and reproduction. The combination of climate forecasts and improved genetic performance, indicate increasingly negative impacts of heat stress for the future. Therefore, future heat stress mitigation approaches will need engineered solutions that also consider expected economic risk and corresponding uncertainty. Physically modifying the environment is currently the best approach by utilizing the heat dissipation (albeit, poor) mechanisms of the pig, that is, via the 4 modes of heat transfer, conduction, convection, radiation, and evaporation. A temperature gradient for sensible or vapor pressure gradient for latent heat loss are needed to drive heat exchange. Strategies can then be grouped into (a) modifying the thermodynamic properties of the incoming air via the ventilation system; (b) building characteristics or features; (c) animal zone environment modification; and (d) changes in management. Examples of each strategy include (a) evaporative cooling pads, earth-air-heat exchanger; (b) insulation, spatial orientation; (c) fogging, cooling the drinking water, increasing air velocity; and (d) stocking density. Engineering of future controlled swine environments will need enhanced modeling of heat transfer between pigs and their environment, advanced design/analysis methods of environmental control, and creation of innovative technology that improves sensing, controlling, and modifying the environment. Much of the engineering process starts with and relies on established standards that describe key analytical methods for design, data to enable design computations, and criteria/goals for different environments. There is and will continue to be a need for consistent updates to these data to ensure modern intensive housing is able to provide the proper thermoneutral zone, ventilation rates, etc. for prolific pigs in a changing climate.

Modeling the relationship between the geometric characteristics of urban green spaces and thermal comfort: The case of Adana city

In recent years, developing heat stress mitigation strategies in urban areas with the help of climate software has become a top priority in climatic studies to eliminate standardisation deficiency. This paper aimed to statistically determine the climatically suitable and least suitable UGS geometric characteristics in different urban morphologies for the hot–humid city of Adana. It combined the climate-based classification of urban morphology with the local climate zone (LCZ), thermal condition analysis of UGS with ENVI-met microclimate software for three different canopy cover scenarios, and statistical analysis results obtained by the one-way ANOVA with post-hoc Tukey-HSD test. Firstly, UGS geometric characteristics (area size, aspect ratio, orientation) and urban morphology were classified. Secondly, mean PET for each UGS and LCZ classes were obtained from ENVI-met. Finally, suitable and least suitable UGS characteristics were determined according to the statistical significance of PET differences (p > 0.05) using the ANOVA Tukey-HSD test analyzes of pairwise comparisons. The statistical analysis results demonstrated that although the suitable and least suitable UGS characteristics differed in the scenarios, the common characteristics were as follows: The suitable UGS were characterised by larger area sizes, rectangular-shaped, N–S or NW–SE-orientated UGS adjacent to low-rise LCZs (LCZ 3, 6, 7, 8, 10), or small area sizes, all shaped and all orientations UGS adjacent and located to the east of high-rise LCZ classes (LCZ 1 and 4). Shading was an important factor positively affecting thermal conditions. Moreover, the wind circulation and wind speed, which also positively affected thermal comfort, were higher for low-rise buildings than high-rise buildings, open settlements than compact settlements, and 100% grass cover than 100% canopy cover. This study's results can serve as a guide for future researchers and decision makers to standardise UGS characteristics in different urban morphologies and to develop climatically comfortable UGS designs and plan strategies that can be implemented in future cities.

A risk index for assessing heat stress mitigation strategies. An application in the Mediterranean context

In many Mediterranean cities, there are densely built up settlements characterized by the lack of green spaces and the abundant use of impervious construction materials, so the phenomenon of heat stress is exacerbated and mitigation strategies are key to improve thermal conditions of pedestrians.The present study aims to evaluate the effectiveness of heat stress mitigation strategies by proposing a new heat stress risk index that comprehensively accounts for hazard, vulnerability and exposure of the urban context. The index is tested with the assessment of two different greenery scenarios based on the introduction of vegetation in the existing street spaces rearranged according to the principles of traffic calming and vertical vegetated surfaces. These scenarios have been simulated in a district of the metropolitan city of Catania (Italy) through the combined use of GIS software and Computational Fluid Dynamics (CFD) simulations in ENVI-met.Results showed that mitigation scenarios improve outdoor thermal conditions for pedestrians because about 66% of the domain area showed Tmrt reductions in the range of 2.5 °C–7.5 °C with respect to the existing scenario. Furthermore, the no hazard area for 80+ residents is increased from 63% of current scenario to 83% of the advanced scenario, thus demonstrating the usefulness of the new index in giving a synthetic measure of effectiveness to decision makers. Further studies are planned to stress the capabilities of the index in contrasting heat stress risk and mitigation solutions for different urban tissues and climates.

Heat stress mitigation in urban streets having hot humid climatic conditions: Strategies and performance results from a real scale retrofitting project

The urban heat island (UHI) phenomenon has become a major concern for city sustainability in the wake of global warming and rapid urbanization. This has resulted in increased heat stress and worsened outdoor thermal comfort in urban microclimates. The study demonstrated that outdoor thermal stress pedestrians can be reduced in single streets by adopting mitigation strategies, that is, cool materials, vegetation, and water bodies. In this article, computational fluid dynamics (CFD) simulations using URANS modeling for four different scenarios have been performed to investigate the effectiveness of different mitigation measures in hot, humid urban climates conditions. The reduction of ambient air temperature and surface temperature characterizing the mitigation (cooling) intensity is examined at pedestrian height and diverse vertical levels. The analysis shows that on its own, water provides the largest reduction in air temperature at pedestrian height (2 °C), and cool materials provide a larger reduction in surface temperature (6 °C). When applied individually, cool materials are the more effective in the vertical direction with a UHI mitigation intensity of 1.5 °C, followed by vegetation, with a mitigation intensity of 1.0 °C. Furthermore, the impact (temperature reduction) is more significant when all three measures are combined, with a large reduction of 2 °C in air temperature and 9 °C in surface temperature observed compared to the reference case.

Impacts, Tolerance, Adaptation, and Mitigation of Heat Stress on Wheat under Changing Climates.

Heat stress (HS) is one of the major abiotic stresses affecting the production and quality of wheat. Rising temperatures are particularly threatening to wheat production. A detailed overview of morpho-physio-biochemical responses of wheat to HS is critical to identify various tolerance mechanisms and their use in identifying strategies to safeguard wheat production under changing climates. The development of thermotolerant wheat cultivars using conventional or molecular breeding and transgenic approaches is promising. Over the last decade, different omics approaches have revolutionized the way plant breeders and biotechnologists investigate underlying stress tolerance mechanisms and cellular homeostasis. Therefore, developing genomics, transcriptomics, proteomics, and metabolomics data sets and a deeper understanding of HS tolerance mechanisms of different wheat cultivars are needed. The most reliable method to improve plant resilience to HS must include agronomic management strategies, such as the adoption of climate-smart cultivation practices and use of osmoprotectants and cultured soil microbes. However, looking at the complex nature of HS, the adoption of a holistic approach integrating outcomes of breeding, physiological, agronomical, and biotechnological options is required. Our review aims to provide insights concerning morpho-physiological and molecular impacts, tolerance mechanisms, and adaptation strategies of HS in wheat. This review will help scientific communities in the identification, development, and promotion of thermotolerant wheat cultivars and management strategies to minimize negative impacts of HS.

Betaine and related compounds: Chemistry, metabolism and role in mitigating heat stress in poultry.

Betaine can operate as an osmolyte and a methyl donor. Betaine is an osmolyte and a methyl donor. Betaine is likewise a zwitterion with osmotic capabilities that can help an animal cope with osmotic stress. Previous investigations have suggested that betaine has various impacts, albeit these studies do not consistently provide the same results. Dietary betaine has received a lot of attention owing to its osmoprotectant, methionine-sparing and antioxidant properties. Betaine is extensively assessed concerning performance and body composition. The tolerance to high temperatures, flock livability, and breast meat output is among the factors frequently mentioned in the literature as being altered by betaine. Betaine, a multi-nutritional agent, may help poultry resist heat stress and poor management. A common subject of betaine research is the idea of betaine saving some methionine. Although research on betaine may not always come to the same results, some discoveries repeat themselves. Because of their effectiveness in increasing growth performance, feed utilization, meat quality, and alleviating heat stress in chicken farms, betaine and methionine are extensively used as feed supplements in poultry diets. This review highlights the influences of betaine on poultry performance, meat quality, carcass characteristics, antioxidant activity, in addition to its role in mitigating heat stress.

Impacts of Air Velocity Treatments under Summer Condition: Part I-Heavy Broiler's Surface Temperature Response.

Simple SummaryThe surface temperature variation of heavy broilers (42–61 d age) under heat stress is an important indicator of thermal comfort, but it is not well studied and reported yet. This study examined the variation of surface temperatures of broilers through two dynamic air velocity treatments under hot summer conditions. It was discovered that the surface temperatures varied over age, daytime, and environmental factors (air temperature, relative humidity, and temperature humidity index). A simple linear regression model to predict the surface temperature of heavy broilers was developed. The findings from this study will enhance knowledge to understand the broilers’ responses under heat stress, which will be helpful in providing necessary management decisions to create a comfortable thermal environment.Heavy broilers exposed to hot summer conditions experience fluctuations in surface temperatures due to heat stress, which leads to decreased performance. Maintaining a bird’s homeostasis depends on several environmental factors (temperature, relative humidity, and air velocity). It is important to understand the responses of birds to environmental factors and the amount of heat loss to the surrounding environment to create thermal comfort for the heavy broilers for improved performances and welfare. This study investigates the variation in surface temperatures of heavy broilers under high and low air velocity treatments. Daytime, age and bird location’s effect on the surface temperature variation was also examined. The experiment was carried out in the poultry engineering laboratory of North Carolina State University during summers of 2017, 2018, and 2019 as a part of a comprehensive study on the effectiveness of wind chill application to mitigate heat stress on heavy broilers. This live broiler heat stress experiment was conducted under two dynamic air velocity treatments (high and low) with three chambers per treatment and 44 birds per chamber. Surface temperatures of the birds were recorded periodically through the experimental treatment cycles (flocks, 35–61 d) with infrared thermography in the morning, noon, evening, and nighttime. The overall mean surface temperature of the broilers under two treatments was found to be 35.89 ± 2.37 °C. The variation in surface temperature happened due to air temperature, thermal index, air velocity, bird’s age, daytime, and position of birds inside the experimental chambers. The surface temperatures were found lower under high air velocity treatment and higher under low air velocity treatment. During the afternoon time, the broilers’ surface temperatures were higher than other times of the day. It was also found that the birds’ surface temperature increased with age and temperature humidity indices. Based upon the experimental data of five flocks, a simple linear regression model was developed to predict surface temperature from the birds’ age, thermal indices, and air velocity. It will help assess heavy broilers’ thermal comfort under heat stress, which is essential to provide a comfortable environment for them.

Crop calendar optimization for climate change adaptation in rice-based multiple cropping systems of India and Bangladesh

Adjusting crop calendars may present an effective adaptation measure to avoid crop yield loss and reduce water use in a changing climate. In order to better understand potentials and limitations of adjusting crop calendars for climate change adaptation of tropical multi-cropping systems with short fallow periods, we used a regionally calibrated Environmental Policy Integrated Climate (EPIC) agronomic model to estimate annual caloric yield and blue water requirement (BWR) of irrigated double-rice and rice-wheat cropping systems in India and Bangladesh. We adjusted crop calendars by (a) single-objective optimization to maximize annual caloric yield and (b) multi-objective optimization to minimize BWR under current and future climate scenarios, focusing on climatic drivers of optimal growing seasons. While the short time intervals between harvest of kharif crops and (trans-)planting of rabi crops limit the space for planting date shift in the study area, our results indicate that crop calendar adjustment has great potential to reverse yield loss induced by temperature rise and decrease BWR by utilizing monsoon precipitation. The study indicates a trend towards earlier planting of rabi wheat to mitigate heat stress during the reproductive stage. Moreover, earlier planting of kharif rice can help to utilize monsoon precipitation, avoid cold stress of kharif rice during anthesis, and allow for early wheat sowing during the historic period. By the 2080s, the increase of heat stress in summer and the decrease of cold stress in winter seems to allow more flexibility for late rice in kharif season, but a conflict between later planting for yield improvement and earlier planting for blue water saving is expected in kharif rice on the Indo-Gangetic plain of India and Bangladesh. Therefore, the trade-off between yield improvement and irrigation water use needs to be carefully considered to promote adaptive adjustment of crop calendars under climate change.

Estimating the Evaporative Cooling Effect of Irrigation within and above Soybean Canopy

Vegetation with an adequate supply of water might contribute to cooling the land surface around it through the latent heat flux of transpiration. This study investigates the potential estimation of evaporative cooling at plot scale, using soybean as example. Some of the plants’ physiological parameters were monitored and sampled at weekly intervals. A physics-based model was then applied to estimate the irrigation-induced cooling effect within and above the canopy during the middle and late season of the soybean growth period. We then examined the results of the temperature changes at a temporal resolution of ten minutes between every two irrigation rounds. During the middle and late season of growth, the cooling effects caused by evapotranspiration within and above the canopy were, on average, 4.4 K and 2.9 K, respectively. We used quality indicators such as R-squared (R2) and mean absolute error (MAE) to evaluate the performance of the model simulation. The performance of the model in this study was better above the canopy (R2 = 0.98, MAE = 0.3 K) than below (R2 = 0.87, MAE = 0.9 K) due to the predefined thermodynamic condition used to estimate evaporative cooling. Moreover, the study revealed that canopy cooling contributes to mitigating heat stress conditions during the middle and late seasons of crop growth.

Effects of Selenium as a Dietary Source on Performance, Inflammation, Cell Damage, and Reproduction of Livestock Induced by Heat Stress: A Review.

Heat stress as a result of global warming has harmful consequences for livestock and is thus becoming an urgent issue for animal husbandry worldwide. Ruminants, growing pigs, and poultry are very susceptible to heat stress because of their fast growth, rapid metabolism, high production levels, and sensitivity to temperature. Heat stress compromises the efficiency of animal husbandry by affecting performance, gastrointestinal health, reproductive physiology, and causing cell damage. Selenium (Se) is an essential nutritional trace element for livestock production, which acts as a structural component in at least 25 selenoproteins (SELs); it is involved in thyroid hormone synthesis, and plays a key role in the antioxidant defense system. Dietary Se supplementation has been confirmed to support gastrointestinal health, production performance, and reproductive physiology under conditions of heat stress. The underlying mechanisms include the regulation of nutrient digestibility influenced by gastrointestinal microorganisms, antioxidant status, and immunocompetence. Moreover, heat stress damage to the gastrointestinal and mammary barrier is closely related to cell physiological functions, such as the fluidity and stability of cellular membranes, and the inhibition of receptors as well as transmembrane transport protein function. Se also plays an important role in inhibiting cell apoptosis and reducing cell inflammatory response induced by heat stress. This review highlights the progress of research regarding the dietary supplementation of Se in the mitigation of heat stress, addressing its mechanism and explaining the effect of Se on cell damage caused by heat stress, in order to provide a theoretical reference for the use of Se to mitigate heat stress in livestock.

Effect of Heat Waves on Some Italian Brown Swiss Dairy Cows' Production Patterns

Climate change is impacting worldwide efficiency and welfare standards in livestock production systems. Considering the sensibility to heat stress reported for different milk production patterns in Italian Brown Swiss, this study aims to evaluate the effect of heat waves (HWs)of different lengths on some milk production traits (fat-corrected milk, energy-corrected milk, protein and fat yield, protein percentage, cheese production at 24 h, and cheese yield). A 10-year dataset (2009–2018), containing 202,776 test-day records from 23,296 Brown Swiss cows, was used. The dataset was merged both with the daily maximum temperature–humidity index (THI) recorded by weather stations and with the daily maximum THI threshold for each trait in Italian Brown Swiss cows. The study considered 4 different HWs according to their length: 2, 3, 4, and 5 consecutive days before the test-day over the weighted THI threshold. Milk production traits were determined as the difference in losses compared to those after only 1 day before the test-day over the weighted maximum THI. All traits showed to be affected by HWs. Particularly, protein percentage losses increased from −0.047% to −0.070% after 2 consecutive days over the daily THI threshold, reaching −0.10% to −0.14% after 5 days (p < 0.01), showing a worsening trend with the increasing length of HWs. First parity cows showed to be more sensitive to HWs than other parity classes, recording greater losses after shorter HWs, compared to multiparous cows, for protein yield and, consequently, for cheese production at 24 h. This suggests a less efficient metabolic response to heat stress and exposure time in primiparous, compared to multiparous cows, probably due to their incomplete growth process that overlaps milk production, making it more difficult for them to dissipate heat. Although actions to mitigate heat stress are always needed in livestock, this study points out that often time exposure to warm periods worsens milk production traits in Brown Swiss cows.

Nanoparticles in Agriculture: Characterization, Uptake and Role in Mitigating Heat Stress

Abiotic stresses like heat, drought, and salinity are among the major threats to sustainable crop production. These stresses induce numerous adverse effects in plants by impairing biochemical, physiological and molecular processes, eventually affecting plant growth, development and productivity. The rising temperature is one of the major causes of heat stress in agriculture. The variation in temperature during crop development has led to devastating agricultural losses in terms of yield. To adapt and mitigate these effects, germplasm scientists and agronomists aim to develop heat-tolerant varieties or cultivars. These efforts generally include the identification of alleles responsible for heat tolerance and their introgression into breeding populations through conventional or biotechnological methods. However, heat tolerance is a very complex physio-biochemical response of plants governed by a number of genes positioned at different loci. The accumulation of various additive gene effects into a single genotype is an extremely tedious and time-consuming process in both plant breeding and biotechnology. Recent advancements in agricultural nanotechnology have raised expectations for sustainable productivity without altering the genetic make-up of plants. In this milieu, the application of biologically active nanoparticles (NPs) could be a novel approach to enhance heat tolerance in crops. Recently, the NPs from silver, silicon, titanium and selenium have been proven valuable for plants to combat heat stress by altering their physiological and biochemical responses. Due to nano-scale size and the high surface area along with their slow and steady release, the NPs exert positive effects in plants through their growth-promoting and antioxidant capabilities. In this review, various technologies used for NPs characterization and their applications in agriculture have been discussed. The review further elaborates the uptake mechanism of NPs and their translocation in different plant parts along with the factors affecting them. This article also describes the role of metal or metal oxide NPs, as well as nano, encapsulated plant growth regulators and signal molecules in heat stress tolerance. The review will provide an insight to the scientists working in the area of agricultural sciences to explore new NPs to encounter different types of biotic and abiotic stresses.

Effects of increased ambient temperature and supplemental altrenogest before pregnancy establishment in gilts.

Heat stress (HS) mitigation strategies are critically needed to combat the substantial economic effects on animal agriculture. The manifestations of seasonal infertility include delayed puberty onset, reduced conception rates, decreased litter size, and increased wean to estrus interval. To assess the effects of HS during early gestation and evaluate the benefit of supplemental altrenogest (ALT) as a mitigation strategy, 30 crossbred postpubertal gilts (157 ± 11 kg body weight) were subjected to estrous synchronization via 14 d oral administration of ALT. Artificial insemination during estrus was performed, and gilts were then placed into one of four treatment groups: HS (35 ± 1 °C for 12 h/31.60 ± 1 °C for 12 h) with (HSALT, n = 7) or without (HSCON, n = 7) 15 mg/d ALT supplementation or thermal neutral (TN; 20 ± 1 °C) conditions with (TNALT, n = 8) or without (TNCON, n = 8) 15 mg/d ALT supplementation until 12 d post-estrus (dpe). Administrating ALT occurred at 0600 hours from 3 to 12 dpe, and rectal temperatures (TR) and respiration rates (RR) were recorded. Blood was collected via jugular venipuncture on 0, 4, 8, and 12 dpe. Gilts were euthanized humanely at 12 dpe followed by the collection of ovarian tissue, and uterine flushing for conceptus collection. In HS compared with TN gilts, RR and TR were increased (P < 0.01) but unaffected by ALT supplementation. Feed intake was reduced (P < 0.01) by HS but unaltered by the ALT treatment. Corpora lutea (CL) weight was reduced (P < 0.01) in HSCON gilts when compared with TNCON and HSALT gilts despite progesterone concentrations in serum and luteal tissue not being affected by treatment (P ≥ 0.10). CL diameter was reduced (P ≤ 0.05) in HSALT gilts compared with other treatments. Interleukin-1β (IL1B) uterine flush concentration was not affected (P > 0.20) by environment or ALT supplementation, although moderate (P = 0.06) interaction between environment and ALT existed, as IL1B concentration in TNALT was increased (P = 0.03) compared with TNCON gilts. While environment did not affect conceptus development (P = 0.90), ALT supplementation advanced conceptus elongation (P < 0.01). Collectively, these data demonstrate that HS may affect luteal development before pregnancy establishment, and ALT increases conceptus elongation by 12 dpe.

Biochemical Characterization and Potential of Bacillus safensis Strain SCAL1 to Mitigate Heat Stress in Solanum lycopersicum L.

Biochemical Characterization and Potential of Bacillus safensis Strain SCAL1 to Mitigate Heat Stress in Solanum lycopersicum L.

Effects of dietary supplementation of ginger, garlic and onion on semen profile, haematological and serum antioxidant status of rabbit bucks raised in the dry season of the humid tropic

Purpose: The study evaluated the semen, haematological and antioxidant status of rabbit bucks fed ginger, garlic and onion supplemented diets under a severely heat stressed condition. This is to evaluate the effect of heat stress and spice supplementation on seminal parameters, haematology and antioxidant capacity of rabbit buck raised in the tropics. Research method: Fifty - five bucks were allotted to 11 treatments comprising of control diet, three each of ginger, garlic and onion at 5g, 10g and 15g/kg feed plus positive control diet. Seminal, haematological and antioxidant traits of the bucks and their pen's Temperature – Humidity index (THI) were observed for 8 weeks. Findings: THI (29.30 - 31.10°C) recorded during the study indicated the prevalence of severe to very severe heat stress. Heat stress impacted negatively more on sperm morphology than on other seminal parameters. Sperm cell motility, viability and abnormality were similar within supplemented groups and the controls. Semen volume and concentration were highest in animals fed garlic at 10 and 15g/kg feed respectively. Spice supplementation had no significant effect (p&gt;0.05) on the haematology and total antioxidant capacity (TAC) of the experimental animals. Originality/value: The study concluded that spice supplementation mitigated heat stress effect on sperm cell morphology and was not deleterious on haematology and TAC of the bucks.

Wisteria trellises and tents as tools for improved thermal comfort and heat stress mitigation: Meteorological, physiological, and psychological analyses considering the relaxation effect of greenery

AbstractIn this study, wet‐bulb globe temperature (WBGT) was measured under wisteria trellises, under tents, and in direct sunlight. In addition, a subject experiment was conducted to consider the relaxation effect of the greenery. In terms of WBGT, the risk of heatstroke under the wisteria trellis was one level lower than that in direct sunlight. The mitigation effect of the wisteria trellis was greater than that of the tent. The difference in WBGT beneath the wisteria trellis and under the tent was primarily due to varied black‐globe temperature (i.e., the difference in radiation environment). The wisteria trellis blocked most of the solar radiation, and its effect on the small aggregation of leaves reduced the increase in the leaf surface temperature and downward longwave radiation. The tent material allowed more solar radiation and increased the temperature of the tent surface. The questionnaire responses revealed that the subjects felt cooler and more comfortable under the wisteria trellis than under the tent, with or without a blindfold.

Drought and heat stress mitigation in rice for yield improvement using temperature induction response technique

The investigation was conducted in two experiments in the College of Agriculture Vellayani, Kerala Agricultural University. First experiment was done to standardize the Temperature Induction Response (TIR) protocol for rice. Second experiment was conducted to study the effect of TIR technique on yield and yield attributes under drought, heat and combined drought and heat stress; 52°C for 3 h was selected as lethal temperature and 32–42°C for 5h & 42–52°C for 30 min were selected as induction temperatures. Results revealed that TIR induction had significant effect on yield and yield attributes under combined drought and heat stress. TIR induced plants without any stress showed the highest growth and yield attributes. Performance of rice genotypes Nagina-22 and Apo improved under combined stress condition using TIR induced seedlings. Apart from these two genotypes, Ptb-15 and Ptb-7 recorded better performance under heat stress and drought, respectively. For combined stress, Ptb-30 and Ptb-15 showed better performance compared to other genotypes. Ptb39 was identified as the most susceptible genotype for both drought and heat stress conditions, but TIR induced plants of susceptible genotype showed improved stress tolerance. Hence, this technique can be used as a potential tool for improving the performance of high yielding abiotic stress susceptible genotypes under stress conditions.