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This document is an editorial from the journal Frontiers in Plant Science titled "The role of lipids in abiotic stress responses." It discusses the importance of lipids in plant responses to environmental stress, such as drought and high temperatures. The editorial highlights the complex relationship between lipids and stress adaptation in plants and emphasizes the need for further research in lipidomics and lipid signaling pathways. The document also mentions specific research papers included in the journal issue, which explore topics such as lipid remodeling in maize hybrids under drought, lipid modulation in peanuts under heat stress, the effect of temperature on lipid accumulation in microalgae, and the identification and expression analysis of KCS genes in soybean in response to abiotic stress. Overall, understanding the role of lipids in stress response is crucial for developing resilient and stress-tolerant crops. [Extracted from the article]

Aphids (Hemiptera: Aphididae) are small, phloem-feeding insects that exhibit remarkable adaptability and resilience to various environmental conditions, including heat stress. Recent research has shed light on the role of bacterial symbionts in influencing the heat tolerance of aphids. Additionally, an intriguing avenue of investigation has explored how aphids can acquire bacterial symbionts through a unique mechanism involving soil nematodes. In this paper, we provide an in-depth overview of the interplay between heat stress, bacterial symbionts, and soil nematodes in the context of aphid biology. In reviewing the existing literature and collating available knowledge, we highlight the mechanisms by which bacterial symbionts contribute to aphid heat stress tolerance and examine the symbiont acquisition process facilitated by soil nematodes. Furthermore, we discuss the implications of these symbiotic associations in relation to the ecology, evolution, and agricultural management of a major globally expanding pest aphid, the corn leaf aphid, Rhopalosiphum maidis (Fitch). Overall, it may be concluded that both primary and secondary bacterial endosymbionts play a significant role in aphid biology with evolutionary consequences. These include adaptations through bacterial symbionts in terms of longevity and fecundity, heat shock tolerance, and resistance to fungal pathogens and primary hymenopterous wasp parasitoids. [ABSTRACT FROM AUTHOR]

This paper aims to provide an updated review and current understanding of the impact of extreme temperatures—focusing on heat stress (HS)—on the quality of pork and poultry meat, particularly amidst an unprecedented global rise in environmental temperatures. Acute or chronic HS can lead to the development of pale, soft, and exudative (PSE) meat during short transportation or of dark, firm, and dry (DFD) meat associated with long transportation and seasonal changes in pork and poultry meat. While HS is more likely to result in PSE meat, cold stress (CS) is more commonly linked to the development of DFD meat. Methods aimed at mitigating the effects of HS include showering (water sprinkling/misting) during transport, as well as control and adequate ventilation rates in the truck, which not only improve animal welfare but also reduce mortality and the incidence of PSE meat. To mitigate CS, bedding on trailers and closing the tracks' curtains (insulation) are viable strategies. Ongoing efforts to minimize meat quality deterioration due to HS or CS must prioritize the welfare of the livestock and focus on the scaleup of laboratory testing to commercial applications. [ABSTRACT FROM AUTHOR]

The object of this study is to predict of human thermophysiological state in hot environment to prevent heat stress or heat stroke. A key issue is the need to design effective tools for heat stroke risk assessment taking into account environmental conditions, physical activity, characteristics of human clothing and protective equipment. A mobile application has been developed, which, unlike existing analogs, provides users with data on the safe time of human under selected environmental conditions. The mobile application uses the method of mathematical modeling to predict important indicators of human thermophysiological state: body temperature, sweat evaporation, body water loss. The mathematical model takes into account the generation of metabolic heat, the transfer of heat inside the body, and the heat exchange of a human with the environment. This paper reports the results of using a mobile application for predicting human thermal responses under hot environmental conditions. With the help of the application, it was possible to determine the time of a human's safe stay depending on the intensity of his/her activity and the characteristics of his/her clothing. It is shown that walking at a speed of 6 km/h in a military uniform is safe for 1 hour at an air temperature of 36 °C. Running at a speed of 8 km/h under such conditions becomes risky already after 15 minutes due to overheating of the human body. The developed information technology is designed to warn about heat stress or heat stroke of people who are under hot conditions in order to preserve their health and work capacity. The received predicting data should be considered as one of the theoretical measures to prevent human heat stress under hot environmental conditions. [ABSTRACT FROM AUTHOR]

The escalating global population and climate change necessitate sustainable livestock production methods to meet rising food demand. Precision Livestock Farming (PLF) integrates information and communication technologies (ICT) to improve farming efficiency and animal health. Unlike traditional methods, PLF uses machine learning (ML) algorithms to analyze data in real time, providing valuable insights to decision makers. Dairy farming in diverse climates is challenging and requires well-designed structures to regulate internal environmental parameters. This study explores the application of the Facebook-developed Prophet algorithm to predict indoor temperatures in a dairy farm over a 72 h horizon. Exogenous variables sourced from the Open-Meteo platform improve the accuracy of the model. The paper details case study construction, data acquisition, preprocessing, and model training, highlighting the importance of seasonality in environmental variables. Model validation using key metrics shows consistent accuracy across different dates, as the mean absolute percentage error on daily base ranges from 1.71% to 2.62%. The results indicate excellent model performance, especially considering the operational context. The study concludes that black box models, such as the Prophet algorithm, are effective for predicting indoor temperatures in livestock buildings and provide valuable insights for environmental control and optimization in livestock production. Future research should explore gray box models that integrate physical building characteristics to improve predictive performance and HVAC system control. [ABSTRACT FROM AUTHOR]

In connection with renewable energy sources, the courtyards of the buildings provide space for the installation of agrivoltaics for sustainable development. This paper proposes the use of courtyards of low-rise buildings for agrivoltaics. This will increase the area for installing photovoltaic systems, which have so far only been installed on roofs or facades or on open fields. The advanced design of the photovoltaic systems will enable the dual use of the area both for the cultivation of crops and for the production of electricity at the same time. The increased amount of electricity produced in photovoltaic systems also contributes to reducing the carbon footprint. On the courtyard as well as on the open fields, it is possible to grow agricultural crops between rows of photovoltaic panels. The partial shading of seedlings during summer sunny days reduces their heat stress and slows down soil drying. Solar eclipses are rare, but their impact on electricity generation is significant. We evaluated the measured data and we assessed the electricity production and the influence of a solar eclipse on the electricity production in photovoltaic power plants in the Czech Republic. The daily loss in production depends on the size of the eclipse. A comparison of the annual electricity production in two selected PV power plants with the expected values according to PVGIS testifies to the quality of the construction and the PV panels used in both power plants. [ABSTRACT FROM AUTHOR]

The genetic progress achieved by animal breeding programs may be affected by genotype-by-climate interactions (GxC). This systematic literature review assesses the scientific evidence for GxC on multiple traits of cattle, pigs, and poultry. Two search engines (Scopus, Web of Science) were queried for original peer-reviewed scientific (English full-text) studies. We included (1) observational studies and designed experiments considering dairy or beef cattle, swine, chicken or turkeys, where (2) at least one production, fertility, or health trait was tested for GxC, (3) the existence of GxC was tested directly based on temperature, relative humidity, or climatic indices for heat or cold stress, and (4) genetic effects within a breed or line were investigated. The search resulted in 46 eligible studies, with a (low) risk that the requirement of full-text English studies may have resulted in some work not included in this review. Our review shows an increase in GxC studies from 2015 onwards. Cattle was the most studied species (n = 36; 78.3%), whereas eligible studies on turkeys were lacking. Climatic parameters used in the studies ranged from well-known parameters (e.g., temperature, temperature-humidity index) to more complex indices combining temperature, relative humidity, wind speed and solar radiation. All observational studies (n = 40; 87.0%) used weather station data. In total, 75 traits were studied, which were predominantly production traits regardless of species. Studies on fertility and health traits have been emerging from 2010 onwards, but their numbers still lag far behind those for production traits. Genotype-by-climate interaction was confirmed in 54.0% of the study outcomes. This systematic review shows that little is known about the role of GxC in health and fertility traits in cattle, and for all traits in pigs and poultry in general. As current evidence shows that genotype-by-climate interaction is common across species and traits, we suggest to collect detailed climatic data and use them to assess the presence of GxC in indoor and outdoor production systems, as well. [ABSTRACT FROM AUTHOR]

Climate change patterns and expected extreme weather conditions drive urban design practices toward more effective adaptation strategies for the built environment. Biskra City, one of the largest urban areas in the Algerian Sahara territory, has suffered from unprecedented extreme weather patterns, specifically during the summer. This paper examined outdoor thermal comfort in the arid climates of Biskra, Algeria, during summer extreme conditions by investigating the impact of the height-to-width (H/W) ratio aspect and the north–south (N-S) and east–west (E-W) street orientations on pedestrian thermal comfort with the parameterization of external building envelopes using brick, concrete, adobe, and limestone materials. This study was conducted with ENVI-met 5.1.1 software, based on 24 parametric scenarios, to identify the most effective composition for outdoor thermal stress mitigation using the physiological equivalent temperature (PET) thermal index. Across all scenarios, the PET index values fluctuated between PETmin = 32.2 °C and PETmax = 60.6 °C at different hours. The coupling between the H/W ratio and street orientation as geometry factors and building envelope characteristics reveals six distinct categories of building materials, each with an impact on outdoor thermal comfort: (1) high cooling (60–100%), (2) medium cooling (40–60%), (3) low cooling (<40%), (4) high heating (60–100%), (5) medium heating (40–60%), and (6) low heating material (<40%). Therefore, in the N-S orientation, limestone walls can provide a cooling efficiency range from 85% to 100% throughout deep and shallow canyons. Contrary to this, brick walls can cause a heat retention range varying from 70% to 93% within the same canyons. When considering extreme summer conditions in arid climates, the results show that the most effective bioclimatic passive strategy that could be achieved is the E-W orientation, within H/W < 1, characterized by a high albedo building material. [ABSTRACT FROM AUTHOR]

Significance: We value comments on our research paper in a Commentary in this issue (Simpson, S Afr J Sci. 2024;120(1/2), Art. #16445). Acknowledging the Universal Thermal Comfort Index (UTCI)'s limitations in capturing individual physiological responses remains important; however, we argue for its appropriateness based on recent thermophysiology and heat exchange advancements during its development and broader alignment with standardised indexing efforts. Our original research paper set out with these considerations in mind, and our conclusions remain valid. We further argue for refinement of the UTCI for specific activities instead of using the PET. Finally, future efforts should focus on monitoring data in real-world scenarios to validate and improve thermal indices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Molecularly adapted: Paper wasps inhabit extremely variable thermal environments. • Normal cellular function: Hsc70 and Hsp83 appear important under benign conditions. • Stress response: Hsp70 and Hsp83 expression is highly induced by severe heat stress. • Development: Expression of Heat Shock Proteins varied between life stages. • Environmental adaptation: Use of the Heat Shock Response differ between populations. Temperature is a crucial factor in many physiological processes, especially in small ectotherms whose body temperature is highly influenced by ambient temperature. Polistes (paper wasps) is a genus of primitively eusocial wasps found in widely varying thermal environments throughout the world. Paper wasps construct open-faced combs in which the brood is exposed to varying ambient temperatures. The Heat Shock Response is a physiological mechanism that has been shown to help cope with thermal stress. We investigated the expression of heat shock proteins in different life stages of three species of Polistes from different climates with the aim of deducing adaptive patterns. This was done by assaying heat shock protein (hsp70 , hsp83 , hsc70) expression during control conditions (25 °C) or a heat insult (35 or 45 °C) in individuals collected from natural populations in Alpine, Temperate, or Mediterranean climates. Basal expression of hsc70 and hsp83 was found to be high, while hsp70 and hsp83 expression was found to be highly responsive to severe heat stress. As expression levels varied based on species, geographical origin, and life stage as well as between heat shock proteins, the Heat Shock Response of Polistes was found to be complex. The results suggest that adaptive utilization of the heat shock response contributes to the ability of Polistes spp. to inhabit widely different thermal environments. [ABSTRACT FROM AUTHOR]

In recent years, the frequency and intensity of exposure to heat stress have increased gradually, seriously hampering the production of maize. This paper presents a study designed to analyze how the development, physiology and dispersal of pollen from the heat‐resistant maize variety Zhengdan958 and the heat‐sensitive maize variety Xianyu335 are affected by exposure to heat stress during the tasselling stage. Our results showed That exposure to heat stress significantly increased the antioxidant enzyme activity in pollen. Upon visual inspection of the pollen, we found that the lower water content had given rise to wrinkles in the pollen surface, sunken germination pores, and morphological deformations. In addition, the anther dehiscence process was hindered, resulting in a reduced amount of pollen being dispersed. We also found elevated levels of abscisic acid (ABA), jasmonic acid (JA) and its derivatives, indole acetic acid (IAA) and gibberellin‐3 (GA3) in heat‐pollens, as well as elevated ratios of IAA to ABA and ABA to GA3. Ultimately impaired pollen fertility. Summarizing, our experiment revealed that reduced pollen quantity and quality are significant contributors to fertility losses in summer maize exposed to heat stress at anthesis, and we hope that our analysis of the physiological mechanisms involved can contribute to the development of crop management measures aimed at countering the increasingly detrimental effects of heat stress on the production of summer maize. [ABSTRACT FROM AUTHOR]

This study develops a quantitative method to assess the thermal usability (e.g., rideability, walkability, entertainmentability, exercisability and workability) of outdoor spaces. The benchmark for thermal usability was assessed by four widely used indicators [wet bulb globe temperature (WBGT), predicted mean vote (PMV), physiologically equivalent temperature (PET) and universal thermal climate index (UTCI)]. Among these five dimensions of thermal usability, exercisability was the most significantly thermally affected, as most of the exercise activities are moderately loaded and heavily loaded, and the exercisability of moderately loaded and heavily loaded would be lower than 33% and 24%, respectively, at WBGT above 30 °C. An empirical study based on field experiments in Changzhou, China, was performed. The results indicated that the quantitative method was capable of assessing the thermal usability of various urban spaces (e.g., basketball court, badminton field, walkway space and natural lawn), and could guide people in spatial modifications, outdoor activities and site management. The empirical studies also showed that airflow and radiation were the two critical meteorological factors, associated with urban infrastructure affecting the thermal usability of outdoor spaces. Activity metabolism showed a positive correlation with participant's heat stress and a negative correlation with the thermal usability. Suggestions were used to guide participants to avoid optional activities and to provide them protective recommendations for necessary activities during periods of low thermal usability. Overall, this paper promotes methodological understandings of thermal usability, and provides policy makers, urban planners and designers, and urban managers with implications on effective heat solutions. [ABSTRACT FROM AUTHOR]

Manual outdoor work is essential in many agricultural systems. Climate change will make such work more stressful in many regions due to heat exposure. The physical work capacity metric (PWC) is a physiologically based approach that estimates an individual's work capacity relative to an environment without any heat stress. We computed PWC under recent past and potential future climate conditions. Daily values were computed from five earth system models for three emission scenarios (SSP1‐2.6, SSP3‐7.0, and SSP5‐8.5) and three time periods: 1991–2010 (recent past), 2041–2060 (mid‐century) and 2081–2100 (end‐century). Average daily PWC values were aggregated for the entire year, the growing season, and the warmest 90‐day period of the year. Under recent past climate conditions, the growing season PWC was below 0.86 (86% of full work capacity) on half the current global cropland. With end‐century/SSP5‐8.5 thermal conditions this value was reduced to 0.7, with most affected crop‐growing regions in Southeast and South Asia, West and Central Africa, and northern South America. Average growing season PWC could falls below 0.4 in some important food production regions such as the Indo‐Gangetic plains in Pakistan and India. End‐century PWC reductions were substantially greater than mid‐century reductions. This paper assesses two potential adaptions—reducing direct solar radiation impacts with shade or working at night and reducing the need for hard physical labor with increased mechanization. Removing the effect of direct solar radiation impacts improved PWC values by 0.05 to 0.10 in the hottest periods and regions. Adding mechanization to increase horsepower (HP) per hectare to levels similar to those in some higher income countries would require a 22% increase in global HP availability with Sub‐Saharan Africa needing the most. There may be scope for shifting to less labor‐intensive crops or those with labor peaks in cooler periods or shift work to early morning. [ABSTRACT FROM AUTHOR]

Heat stress (HS) can cause damage to the organism, especially the intestinal tract. In this paper, we investigated the effects of the combined action of tea polyphenols (TP) and hydrogen-rich electrolyzed water (HRW) on HS in mice. The combination of HRW feeding and TP of intraperitoneal injection was screened by in vitro antioxidant activity assay. The results revealed that the combined treatment was more helpful in alleviating the effects of HS on the behavior, growth performance, oxidative damage, and intestinal tract of mice compared with the respective treatments of TP and HRW (P < 0.05). Additionally, the combined treatment could repair HS-induced intestinal dysbiosis in mice, augmenting the number and abundance of bacteria, increasing the number of beneficial genera (Lachnospiraceae_NK4A136_group and Lactobacillus), and decreasing the number of harmful genera (Desulfovibrio and Enterorhabdus), and the effect was significantly better than that of individual treatment (P < 0.05). In conclusion, the combined treatment of TP and HRW effectively mitigates the adverse effects of HS on mouse behavior, growth performance, oxidative damage, and intestinal dysbiosis, surpassing the efficacy of individual treatments with TP or HRW alone. [Display omitted] • Combined treatment of drinking HRW and injecting TP (HRW + TP) was screened. • HRW + TP attenuated HS effects on behavior, growth performance, oxidative damage and intestinal tract of mice. • HRW + TP increased beneficial genera and decreased harmful genera. • HRW + TP mitigates the effects of HS-mice better than treatment alone. [ABSTRACT FROM AUTHOR]

Introduction: Increasing global temperatures present a significant challenge to livestock production. The dry period is an important stage in the production cycle of cow, and environmental heat stress (HS) during this period can have adverse effects on the subsequent lactation performance. In this study, we aimed to investigate the effects of HS on endocrine, thermoregulatory, and lactation parameters in heat-tolerant dry cows (HTDC) and heat-sensitive dry cows (HSDC). Methods: We measured the respiratory rate (RR), body temperature (BT), and temperature-humidity index (THI) in 66 dry cows during HS. The slopes of RR and BT to THI were determined through analysis of measurements and dry cows background information using a mixed-effects model. Subsequently, the heat tolerance or sensitivity of dry cows was assessed using clustering method (HTDC = 19 and HSDC = 47). Results: Compared with that of HSDC, the RR of HTDC significantly increased after exposure to HS (p < 0.05). The average reduction in milk yield from new lactation to the previous lactation was significantly lower in HTDC compared to HSDC (p < 0.05). Plasma cortisol and non-esterified fatty acid levels were significantly lower in HTDC compared to HSDC (p < 0.05), while plasma triiodothyronine (p = 0.07) and growth hormone (p = 0.08) levels tended to be higher in HTDC relative to HSDC. Discussion: HTDC can more effectively alleviate the impacts of HS through their superior thermoregulation and metabolism, thereby ensuring optimal postpartum lactation performance. [ABSTRACT FROM AUTHOR]

Simple Summary: Heat stress is a major problem for the health and productivity of livestock, including cattle. Since the 1950s, researchers have studied how high environmental temperature affects cattle fertility through both laboratory and field studies. When a cow's rectal or vaginal temperature goes above 39.1 °C, it is considered heat-stressed, which can harm its ability to reproduce. However, there is not enough information about temperatures in the uterus, oviducts, and ovarian follicles, especially in lactating dairy cows, to ensure current laboratory models are accurate. These data are crucial for understanding how heat stress impacts oocyte (egg) development and early embryo survival in cattle. Additionally, it is important to improve live animal stress models to correctly identify when cows are truly experiencing heat stress, shown by signs like increased panting, body temperature, and heart rate, rather than just assuming they are stressed based on exposure to a high temperature–humidity index. Improving these models will make them more reliable and help identify cattle that can better tolerate heat. Rectal and vaginal temperatures are utilised in both in vivo and in vitro models to study the effects of heat stress on oocyte competence and embryo viability in cattle. However, uterine temperature increases by only 0.5 °C in heat-stressed cows, significantly lower than simulated increases in in vitro models. Temperature variations within oviducts and ovarian follicles during heat stress are poorly understood or unavailable, and evidence is lacking that oocytes and pre-implantation embryos experience mild (40 °C) or severe (41 °C) heat stress inside the ovarian follicle and the oviduct and uterus, respectively. Gathering detailed temperature data from the reproductive tract and follicles is crucial to accurately assess oocyte competence and embryo viability under realistic heat stress conditions. Potential harm from heat stress on oocytes and embryos may result from reduced nutrient availability (e.g., diminished blood flow to the reproductive tract) or other unidentified mechanisms affecting tissue function rather than direct thermal effects. Refining in vivo stress models in cattle is essential to accurately identify animals truly experiencing heat stress, rather than assuming heat stress exposure as done in most studies. This will improve model reliability and aid in the selection of heat-tolerant animals. [ABSTRACT FROM AUTHOR]

Background: At present, heat stress (HS) has become a key factor that impairs broiler breeding industry, which causes growth restriction and poor meat quality of broilers. Selenium (Se) is an excellent antioxidant and plays a unique role in meat quality improvement. Recent years, nano-selenium (NanoSe) has received tremendous attention in livestock production, due to its characteristic and good antibacterial performance in vitro. Here, we developed the heat stressed-broiler model to investigate the protective effects of NanoSe on growth performance and meat quality of broilers and compare whether there are differences with that of other Se sources (Sodium selenite, SS; Selenoyeast, SeY; Selenomethionine, SeMet). Results: HS jeopardized the growth performance and caused poor meat quality of breast muscle in broilers, which were accompanied by lowered antioxidant capacity, increased glycolysis, increased anaerobic metabolism of pyruvate, mitochondrial stress and abnormal mitochondrial tricarboxylic acid (TCA) cycle. All Se sources supplementation exhibited protective effects, which increased the Se concentration and promoted the expression of selenoproteins, improved the mitochondrial homeostasis and the antioxidant capacity, and promoted the TCA cycle and the aerobic metabolism of pyruvate, thus improved the breast muscle meat quality of broilers exposed to HS. However, unlike the other three Se sources, the protective effect of NanoSe on meat quality of heat stressed-broilers was not ideal, which exhibited limited impact on the pH value, drip loss and cooking loss of the breast muscle. Compared with the other Se sources, broilers received NanoSe showed the lowest levels of slow MyHC, the highest levels of fast MyHC and glycogen, the highest mRNA levels of glycolysis-related genes (PFKM and PKM), the highest protein expression of HSP60 and CLPP, and the lowest enzyme activities of GSH-Px, citroyl synthetase (CS) and isocitrate dehydrogenase (ICD) in breast muscle. Consistent with the SS, the Se deposition in breast muscle of broilers received NanoSe was lower than that of broilers received SeY or SeMet. Besides, the regulatory efficiency of NanoSe on the expression of key selenoproteins (such as SELENOS) in breast muscle of heat stressed-broilers was also worse than that of other Se sources. Conclusion: Through comparing the meat quality, Se deposition, muscle fiber type conversion, glycolysis, mitochondrial homeostasis, and mitochondrial TCA cycle-related indicators of breast muscle in heat stressed broilers, we found that the protective effects of organic Se (SeY and SeMet) are better than that of inorganic Se (SS) and NanoSe. As a new Se source, though NanoSe showed some protective effect on breast muscle meat quality of heat stressed broilers, the protective effect of NanoSe is not ideal, compared with other Se sources. [ABSTRACT FROM AUTHOR]

The global human population is projected to reach 9.7 billion by 2050, increasing the demand for food and fiber, but also raising concerns about the environmental impact of agricultural production scaled to meet their needs. Silvopastures—integrated tree–forage–livestock systems—have emerged as a viable practice to meet the required productivity and environmental stewardship outcomes. This review consolidates the extensive research on silvopasture practices in the United States and highlights the benefits of these systems. A comprehensive literature search across databases such as ScienceDirect and Google Scholar revealed 152 publications on silvopastures in the United States since 2000, indicating growing interest. These studies have primarily focused on the impacts of silvopastures on livestock welfare and productivity, forage production and composition, soil health and nutrient dynamics, and socio-economic factors. Geographical distribution analysis indicated that the research is more focused in the Southeastern United States, with Florida, Virginia, Alabama, Missouri, and Arkansas being the top five contributing states. The review also offers insights into the tree and forage species used across these states and discusses the challenges to silvopasture adoption among producers and land managers while exploring future prospects. This review may be used as a resource for understanding the multifaceted dimensions of silvopasture adoption, providing insights for researchers, policymakers, and practitioners alike. [ABSTRACT FROM AUTHOR]

Delta-12 fatty acid desaturases (FAD2s) actively regulate stress responses and cell differentiation in living organisms. In this study, six homologous FAD2 genes were identified based on the genome sequence of Lentinula edodes. Then, the six FAD2 protein sequences were analyzed using bioinformatics tools, including ExPASy ProtParam, SignalP, TMHMM, and TargetP. These analyses were performed to predict the physical and chemical properties, signal peptides, and transmembrane and conserved domains of these proteins. The polypeptide sequences were aligned, and a maximum likelihood phylogenetic tree was constructed using MEGA 7.0 software to elucidate the phylogenetic relationships between homologous FAD2 sequences. The results demonstrated that the FAD2 proteins contained three conserved histidine-rich regions (HXXXH, HXXHH, and HXXHH), which included eight histidine residues. The linoleic acid content and FAD2 enzyme activity were further analyzed, and the levels in the mutagenic heat-tolerant strain 18N44 were lower than those in the wild-type strain 18. Interestingly, the expression levels of the FAD2-2 and FAD2-3 genes under heat stress in strain 18N44 were lower than those in strain 18. These findings indicated that FAD2-2 and FAD2-3 may play major roles in the synthesis of linoleic acid during heat stress. [ABSTRACT FROM AUTHOR]

Heat stress presents a substantial challenge for the poultry industry, negatively impacting broilers' health, growth, and productivity. Optimizing dietary crude protein (CP) levels is a viable approach to reduce the heat generated during birds' amino acid oxidation process. Additionally, supplementing diets with Selenium (Se), a potent antioxidant, can help counteract the detrimental effects of heat stress on broiler growth performance. To explore the effects of varying CP and Se levels on growth performance, carcass characteristics, blood parameters, immune function, and blood leukocyte profiles in broiler chickens under heat stress, a 42- day experiment was conducted. It involved 528 male broiler chicks (Ross 308), divided into six groups with 11 chicks each, fed diets with 100%, 94%, or 88% of the recommended CP levels, and two Se levels (0 and 0.04 mg/kg). The findings indicated that reducing dietary CP levels led to an improvement in daily weight gain (DWG) without affecting feed intake (FI), feed conversion ratio (FCR), or carcass traits. There was a significant interaction between CP and Se levels regarding glucose, albumin, uric acid, cholesterol, triglyceride levels, antibody titers against Newcastle disease virus (NDV), and monocyte counts. Se supplementation increased NDV antibody titers at 14 days, whereas reducing CP lowered these titers at 21 days. The study concluded that lowering dietary CP did not adversely affect growth performance, carcass quality, or blood parameters; it even enhanced DWG compared to a normal protein diet and influenced some blood parameters. [ABSTRACT FROM AUTHOR]

Most canopy-forming macroalgae have disappeared from temperate reefs in southern Japan, one of the ocean warming hotspots, but Sargassum nipponicum is surviving in this region. As this species' annual shoots emerge from holdfasts during summer, both plant components may be highly tolerant to warm and nutrient-poor conditions in this season. The present study examined the effects of temperature and nutrient conditions on holdfast growth, shoot emergence from holdfasts, and shoot growth in S. nipponicum samples collected in Tanegashima Island, southern Japan. The summer temperature in this region (30 °C) allowed holdfast growth and shoot emergence but inhibited shoot growth. Nutrient-poor conditions had limited effects on the first two parameters but suppressed shoot growth. These results suggested that during warm summers and under nutrient-poor conditions in southern Japan, shoots can emerge from S. nipponicum holdfasts but cannot further grow. Additionally, nutrient loading from a nearby river was higher at the only site dominated by S. nipponicum, than at the other sites where this species was absent on Tanegashima Island. This was observed especially between autumn and winter, implying that such a nutrient-rich environment may contribute to shoot growth in S. nipponicum and to the persistence of its population in the area. [ABSTRACT FROM AUTHOR]

Simple Summary: Summer heat stress adversely affects the productivity and economic viability of lactating Holstein cows. We explored the effects of dietary supplementation with L-tryptophan or L-ascorbic acid on milk production characteristics and plasma metabolites in lactating Holstein cows during the summer. The results showed that the supplementation with L-tryptophan or L-ascorbic acid reduced heat stress in lactating Holstein cows during the summer. In particular, L-tryptophan supplementation increased the concentration of melatonin in milk. However, there were no significant differences in milk yield or composition between the treatments. Therefore, further research is needed to explore the effects of increasing the dosage of supplements and to investigate the combination strategies of the dietary supplements used in the current study. This study investigated the effects of rumen-protected L-tryptophan or L-ascorbic acid supplementation on the productivity of lactating Holstein cows during a high-temperature period. Thirty cows were assigned to three dietary groups: control (CON), treatment 1 (TRT 1; rumen-protected L-tryptophan, 20 g/cow/d), and treatment 2 (TRT 2; rumen-protected L-ascorbic acid, 20 g/cow/d). As the high-temperature period progressed, the decrease in milk yield and dry matter intake (DMI) in the TRT 1 and TRT 2 groups was lower than that in the CON group. The total protein level in the plasma of the TRT 1 group was higher than that in the CON group (p < 0.05). Milk melatonin concentration was higher in the TRT 1 group than in the CON and TRT 2 groups (p < 0.05). Thus, the present results indicate that rumen-protected L-tryptophan or L-ascorbic acid has positive effects in preventing declines in DMI and milk yield by reducing heat stress in Holstein cows. In particular, rumen-protected L-tryptophan is considered effective in increasing the melatonin concentration in milk. [ABSTRACT FROM AUTHOR]

Simple Summary: The search for housing systems that contribute to increases in productivity and milk quality with the meticulous use of resources is one of the main challenges with modern livestock. In this sense, the compost-bedded pack barn (CBP) is a promising alternative for raising dairy cattle. However, answers regarding the applicability of this system to the conditions of tropical and subtropical climates are lacking, focusing on Brazil. The objective of this study was to gather and describe the most recent information on open and closed CBP for dairy cattle. Properly designed, open CBP facilities with suitably designed ventilation systems and effective bedding management show potential for the climatic conditions and building typologies in Brazil. Most studies on the closed CBP system have provided only preliminary impressions because limited amounts of data have been collected. The first results demonstrate serious challenges with bedding management. The discussed results can be used to guide decision-making processes to create suitable environmental conditions for CBP systems. The main challenge in milk production has been to maintain a focus on efficient processes that enhance production outcomes while aligning with animal welfare and sustainability and being valued by society. As an alternative to improve cow welfare in production and provide better handling of the waste generated by the activity, the system called the compost-bedded pack barn (CBP) has been widely adopted in countries with temperate climates and higher milk production. This CBP has been attracting global interest, including from countries with tropical and subtropical climates, such as Brazil, where many producers have started to use it due to the response in terms of milk productivity. A CBP can be designed either in (a) an open facility with natural ventilation or a positive-pressure ventilation system or (b) totally closed facilities, equipped with negative-pressure ventilation systems and permanent thermal control. The latter system is being implemented in Brazil, despite insufficient knowledge about its efficiency. The objective of this study was, through a review, to gather and describe the most recent information on the use of open and closed CBP systems for dairy cattle housing, mainly covering how it is applied in tropical climate regions. To achieve the proposed objective, this review study included the following topics related to CBPs: (i) implementation, (ii) bedding, (iii) general construction and architectural characteristics, and (iv) ambient thermal conditioning. Knowledge gaps and directions for future research are also identified here. [ABSTRACT FROM AUTHOR]

Simple Summary: This review aims to discuss the hypothalamic control of hyperthermia in livestock, including the main physiological and behavioral changes that animals adopt to maintain their thermal stability. This review analyzes the main changes that can be observed in livestock when exposed to intense heat. Vasodilation, sweating, and behavioral modifications (e.g., standing posture, shade seeking, feed intake, among others) are the results of neuronal projections from peripheral thermoreceptors to the preoptic area of the hypothalamus and effector neurons. Understanding these mechanisms can help to visualize their effect to restore thermal neutrality in livestock. Hyperthermia elicits several physiological and behavioral responses in livestock to restore thermal neutrality. Among these responses, vasodilation and sweating help to reduce core body temperature by increasing heat dissipation by radiation and evaporation. Thermoregulatory behaviors such as increasing standing time, reducing feed intake, shade-seeking, and limiting locomotor activity also increase heat loss. These mechanisms are elicited by the connection between peripheral thermoreceptors and cerebral centers, such as the preoptic area of the hypothalamus. Considering the importance of this thermoregulatory pathway, this review aims to discuss the hypothalamic control of hyperthermia in livestock, including the main physiological and behavioral changes that animals adopt to maintain their thermal stability. [ABSTRACT FROM AUTHOR]

Introduction: In the Near East and North Africa (NENA) region, crop production is being affected by various abiotic factors, including freshwater scarcity, climate, and soil salinity. As a result, farmers in this region are in search of salt-tolerant crops that can thrive in these harsh environments, using poor-quality groundwater. The main staple food crop for most of the countries in this region, Tunisia included, is barley. Methods: The present study was designed to investigate the sensitivity and tolerance of six distinct barley genotypes to aridity and salinity stresses in five different natural field environments by measuring their photosynthetic activity. Results and discussion: The results revealed that tolerant genotypes were significantly less affected by these stress factors than sensitive genotypes. The genotypes that were more susceptible to salinity and aridity stress exhibited a significant decline in their photosynthetic activity. Additionally, the fluorescence yields in growth phases J, I, and P declined significantly in the order of humid environment (BEJ), semi-arid site (KAI), and arid environment (MED) and became more significant when salt stress was added through the use of saline water for irrigation. The stress adversely affected the quantum yield of primary photochemistry (jP0), the quantum yield of electron transport (jE0), and the efficiency by trapped excitation (y0) in the vulnerable barley genotypes. Moreover, the performance index (PI) of the photosystem II (PSII) was found to be the most distinguishing parameter among the genotypes tested. The PI of sensitive genotypes was adversely affected by aridity and salinity. The PI of ICARDA20 and Konouz decreased by approximately 18% and 33%, respectively, when irrigated with non-saline water. The reduction was even greater, reaching 39%, for both genotypes when irrigated with saline water. However, tolerant genotypes Souihli and Batini 100/1B were less impacted by these stress factors. The fluorescence study provided insights into the photosynthetic apparatus of barley genotypes under stress. It enabled reliable salinity tolerance screening. Furthermore, the study confirmed that the chlorophyll a fluorescence induction curve had an inflection point (step K) even before the onset of visible signs of stress, indicating physiological disturbances, making chlorophyll fluorescence an effective tool for identifying salinity tolerance in barley. [ABSTRACT FROM AUTHOR]

Simple Summary: Nanotechnology offers a unique opportunity to incorporate nanoparticles as alternative sources of trace minerals in animal diets. The purpose of this study was to investigate the effects of applying different concentrations of nano-Se on the growth performances, carcass features, serum components, and gene expressions in heat-stressed Japanese quails. The performance of heat-stressed quails was greatly enhanced by the addition of nano-Se, particularly at the level of 0.2 mg/kg of feed, which also repaired the blood oxidative state. The 0.2 nano-Se-exposed group showed a substantial downregulation of the IL-2, IL-4, IL-6, and IL-8 genes and an upregulation of the SOD and GPX genes in comparison to the heat stress group, indicating that nano-Se had an ameliorative effect on heat stress. It was determined that modest levels of nano-Se in growing heat-stressed quails yield the best results, and its supplementation can be viewed as a protective management strategy in Japanese quail diets to lessen the adverse effects of heat stress. Nano-minerals are employed to enhance mineral bioavailability thus promoting the growth and well-being of animals. In recent times, nano-selenium (nano-Se) has garnered significant attention within the scientific community owing to its potential advantages in the context of poultry. This study was conducted to explore the impact of using variable levels of nano-Se on the growth performance, carcass characteristics, serum constituents, and gene expression in growing Japanese quails under both thermoneutral and heat stress conditions. A randomized experimental design was used in a 2 × 3 factorial, with 2 environmental conditions (thermoneutral and heat stress) and 3 nano-Se levels (0, 0.2, and 0.5 mg/kg of diet. The findings revealed that heat stress negatively affected the growth and feed utilization of quails; indicated by the poor BWG and FCR. Additionally, oxidative stress was aggravated under heat stress condition; indicated by increased lipids peroxidation and decreased antioxidant enzymes activities. The addition of nano-Se, especially at the level of 0.2 mg/kg of diet, significantly improved the performance of heat stressed quails and restored blood oxidative status. The expression profile of inflammatory and antioxidant markers was modulated by heat stress and/or 0.2 and 0.5 nano-Se in conjunction with environmental temperature in quail groups. In comparison to the control group, the heat stress-exposed quails' expression profiles of IL-2, IL-4, IL-6, and IL-8 showed a notable up-regulation. Significantly lower levels of the genes for IL-2, IL-4, IL-6, and IL-8 and higher levels of the genes for SOD and GPX as compared to the heat stress group demonstrated the ameliorative impact of 0.2 nano-Se. The expression profiles of IL-2, IL-4, IL-6, and IL-8 are dramatically elevated in quails exposed to 0.5 nano-Se when compared to the control group. SOD and GPX markers, on the other hand, were markedly down-regulated. It was concluded that nano-Se by low level in heat stressed growing quails provides the greatest performance and its supplementation can be considered as a protective management practice in Japanese quail diets to reduce the negative impact of heat stress. [ABSTRACT FROM AUTHOR]

Small-scale poultry production in Africa plays a significant role in alleviating malnutrition and poverty in rural communities. Global climate change and infectious poultry disease such as Newcastle disease (ND) have had tremendous negative impact on poultry production and health due to limited biosecurity, cold chain, and inadequate extension service. Genetic selection for enhanced resistance to ND virus (NDV) offers a promising complementary approach to vaccination and biosecurity in addressing constraints in village production systems. The Feed the Future Innovation Lab for Genomics to Improve Poultry (GIP IL) has led an effort on the identification of genetic markers, genes and signalling pathways associated with enhanced resistance to NDV by conducting NDV challenging experiments in diverse inbred, commercial, and African indigenous chickens. The GIP IL developed a comprehensive genetic selection platform focusing on improved survival time and reduced virus shedding in the face of NDV infection and on enhanced growth rate and egg production. The programme applied the platform for genetic selection and breeding of indigenous chickens through velogenic NDV natural exposure trials. To improve our understanding of the epidemiology of NDV in Africa, we characterised circulating strains of the virus in Ghana and Tanzania and identified NDV risk factors among local chickens. These data contribute to a body of knowledge useful for guiding disease control efforts, informing vaccine strategies, enhancing biosecurity, and contributing to our overall understanding of NDV dynamics. To gauge the demand for genetically improved indigenous poultry lines, we undertook assessments of the poultry value chain and conducted choice experiments in Ghana and Tanzania, and the findings suggest that both ND enhanced resistance attribute and other productivity attributes of chicken such as egg production and body weight gain are important for a breeding programme. [ABSTRACT FROM AUTHOR]

Rhododendron plants have ornamental, commercial, and medicinal value to people. Flavonoids are one of the components used in traditional remedies, and Rhododendron plants are found to be rich in flavonoids. Flavonoids can reduce the risk of human disease and participate in the regulation of antioxidant defense systems in response to heat stress. Rhododendron prefers cold climates, so the relatively high temperatures of cities affect the extraction of medicinal ingredients and limit the cultivation environment. Recent studies found that the exogenous application of calcium acts to alleviate heat stress in Rhododendron plants. This study explores the mechanism by which exogenous calcium alleviates heat stress and the role of flavonoids in regulating the antioxidative system in Rhododendron × pulchrum Sweet using combined transcriptomic and metabolomic methods. The activities of peroxidase, catalase and superoxide enzymes were found to increase in response to heat stress and external CaCl2 in the leaves of R. × pulchrum. In total, 433 metabolic components and 370 DEGs were identified as being differentially expressed in response to heat stress and external calcium chloride (CaCl2) in the leaves of R. × pulchrum. These results illustrate that heat stress induces oxidative stress and that external CaCl2 can enhance the heat tolerance of Rhododendron. Flavonoid compounds are responsible for the antioxidant scavenging of reactive oxygen species in R. × pulchrum leaves exposed to heat stress and external calcium. [ABSTRACT FROM AUTHOR]