Journal of thermal biology最新文献

{"title":"Microhabitat selection and thermoregulation in amazonian dragonflies","authors":"Suellen Furtado Vinagre ,&nbsp;Lenize Batista Calvão ,&nbsp;Alex Córdoba-Aguilar ,&nbsp;Rhainer Guillermo Ferreira ,&nbsp;e Leandro Juen","doi":"10.1016/j.jtherbio.2024.103998","DOIUrl":"10.1016/j.jtherbio.2024.103998","url":null,"abstract":"<div><div>Insect eco-physiological traits are important for understanding their distribution and habitat selection, especially in the face of land use change. We estimated the average temperature of the thoracic surface of 20 Odonata (Insecta) species and classified them into thermoregulation categories according to their preferences for sunny or shaded habitats to assess their temperature variation. We tested the influence of air temperature and six morphological metrics related to thorax and abdomen size. We expected that: (i) heliothermic species would have higher thoracic temperatures compared to thermoconformer species; (ii) Zygopterans, due to their smaller body size, are less efficient at maintaining a constant body temperature relative to the air when compared to anisopterans; (iii) thorax volume would cause an increase in Odonata thoracic temperature, and abdomen length would cause a decrease. The study was conducted at 18 Amazonian streams in Eastern Amazonia. We observed differences of 2.5 °C in thoracic temperature between heliothermic and thermoconformer species, as predicted in the first hypothesis. Both suborders, Zygoptera and Anisoptera, use different morphological and environmental variables to control temperature. While Zygoptera thoracic temperature oscillated near and below air temperature (−1.28 ± 0.62), Anisoptera maintained temperatures above air temperature (1.81 ± 1.96). Air temperature influenced only the increase in Zygoptera thoracic temperature, supporting our second hypothesis. The third hypothesis was corroborated for order Odonata, but partially for its suborders. Zygoptera thoracic temperature was only related to abdomen length, which was proportional to a temperature decrease. Anisoptera temperature showed a relationship only with thoracic metrics, especially thorax volume, which had a significant contribution to temperature increase. Despite the observed differences, which varied according to size, we noted exceptions in the thermal characteristics of some species that deviated from these predictions. Therefore, we emphasize the importance of considering the interaction of other eco-physiological aspects in dragonfly temperature regulation.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142577776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal and depth-dependent thermoregulatory benefits of burrows for wombats – The largest burrowing marsupials","authors":"Shane D. Morris ,&nbsp;Christopher N. Johnson ,&nbsp;Barry W. Brook ,&nbsp;Michael R. Kearney","doi":"10.1016/j.jtherbio.2024.103961","DOIUrl":"10.1016/j.jtherbio.2024.103961","url":null,"abstract":"<div><div>Mammals use burrows to behaviourally thermoregulate, save water, and avoid predation. The advantages of burrows vary not only seasonally but also with burrow depth. To quantify these effects, we used biophysical ecological models, which predict an animal's energetic and hydric costs within a characterised microclimate. For Australia's three extant wombat species, we quantified variation in the energetic advantage of burrows spatially, temporally, and with burrow depth. We simulated resting wombats with different traits (e.g., body size, fur) in different microclimates (above ground and burrows of varying depth) at six sites across Australia, two for each wombat species, over five years (1980, 1990, 2000, 2010, 2020). We assessed time spent within their thermoneutral zone—heat production equals heat loss thus minimising energy and water expenditure —and frequency of extreme heat stress (i.e., no viable hydric solution for the conditions stipulated). Our findings show that burrows are essential for reducing energetic and hydric costs and for survival during the hottest season in areas with no shade, e.g., the semi-arid zone. We found no evidence that extreme heat stress has increased temporally i.e., due to climate change, but it was frequently predicted in shallow burrows in 2020, having rarely been previously forecast. For energy requirements, we found lower thermoregulatory costs for deeper burrows in the cold season and for shallow burrows in the hot season. This work underscores the critical balance between wombat survival, burrow utility, and environmental dynamics, offering new insights into mechanisms that dictate mammal behaviour from a thermoregulatory perspective.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increased offspring size and reduced gestation length in an ectothermic vertebrate under a worst-case climate change scenario","authors":"David L. Hubert ,&nbsp;Ehren J. Bentz ,&nbsp;Robert T. Mason","doi":"10.1016/j.jtherbio.2024.103990","DOIUrl":"10.1016/j.jtherbio.2024.103990","url":null,"abstract":"<div><div>As global temperatures continue to rise, understanding the impacts of warming environments has become increasingly important. Temperature is especially relevant for ectothermic organisms which depend upon consistent and predictable annual temperature cycles for reproduction and development. However, additional research is required in this area to elucidate the potential impacts of climate change on future generations. To understand how projected increases in environmental temperatures may impact reproductive outcomes within natural populations of ectothermic vertebrates, we manipulated minimum ambient temperatures during gestation in Red-sided garter snakes (<em>Thamnophis sirtalis parietalis</em>). Wild snakes were collected in the Interlake region of Manitoba, Canada during their spring mating season and allowed to mate in controlled conditions. For the duration of gestation, mated females were placed into one of two ambient thermal conditions: temperatures emulating those found in the species’ natural habitat or temperatures with a consistent 5 °C increase to match end-of-century climate change projections. We recorded observations for each litter and all neonates resulting from controlled mating trials. We observed no difference in litter sizes or birth rates between thermal conditions. However, we observed a significant reduction in gestation length and significant increase to neonate body mass and body condition associated with increased ambient temperatures. These results suggest that increased minimum temperatures during gestation may confer reproductive benefits for the northern populations of this species even under the most extreme current modeled warming predictions. We discuss the broader implications of this effect, including possible negative ecological outcomes.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142468718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advances in understanding Lepidoptera cold tolerance","authors":"Hamzeh Izadi ,&nbsp;Ross N. Cuthbert ,&nbsp;Phillip J. Haubrock ,&nbsp;David Renault","doi":"10.1016/j.jtherbio.2024.103992","DOIUrl":"10.1016/j.jtherbio.2024.103992","url":null,"abstract":"<div><div>Ambient thermal conditions mediate insect growth, development, reproduction, survival, and distribution. With increasingly frequent and severe cold spells, it is critical to determine low-temperature performance and cold tolerances of ecologically and economically essential insect groups to predict their responses to global environmental change. This review covers the cold tolerance strategies of 49 species of Lepidoptera (moths and butterflies), focusing on species that are known as crop pests and crop storage facilities. We synthesize cold tolerance strategies of well-studied species within this order, finding that diapause is a distinctive mechanism that has independently evolved in different genera and families of Lepidoptera. However, the occurrence of diapause in each life stage is specific to the species, and in most studied lepidopteran species, the feeding stage (as larva) is the predominant overwintering stage. We also found that the onset of diapause and the improvement of cold tolerance are interdependent phenomena that typically occur together. Moreover, adopting a cold tolerance strategy is not an inherent, fixed trait and is greatly influenced by a species' geographic distribution and rearing conditions. This review further finds that freeze avoidance rather than freeze tolerance or chill susceptibility is the primary cold tolerance strategy among lepidopteran species. The cold hardiness of lepidopteran insects primarily depends on the accumulation of cryoprotectants and the depression of the supercooling point. We highlight variations in cold tolerance strategies and mechanisms among a subset of Lepidoptera, however, further work is needed to elucidate these strategies for the vast numbers of neglected species and populations to understand broad-scale responses to global change.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Validity of the estimated core temperature algorithm during real-world prolonged walking exercise under warm ambient conditions","authors":"Mandy A.G. Peggen ,&nbsp;Coen C.W.G. Bongers ,&nbsp;Johannus Q. de Korte ,&nbsp;Bertil J. Veenstra ,&nbsp;Koen Levels ,&nbsp;Maria T.E. Hopman ,&nbsp;Thijs M.H. Eijsvogels","doi":"10.1016/j.jtherbio.2024.103982","DOIUrl":"10.1016/j.jtherbio.2024.103982","url":null,"abstract":"<div><h3>Background</h3><div>Non-invasive methods to estimate core body temperature (T_C) are increasingly available. We examined the group-level and individual participant-level validity of the Estimated Core Temperature (ECTemp™) algorithm to estimate T_C based on sequential heart rate (HR) measurements during real-world prolonged walking exercise in warm ambient conditions.</div></div><div><h3>Methods</h3><div>Participants walked 30 (n = 3), 40 (n = 13) or 50 (n = 2) km on a self-selected pace during which T_C was measured every minute using an ingestible temperature capsule. HR was measured every second and used to compute the estimated core temperature (T_C-est) using the ECTemp™ algorithm. Bland-Altman analyses were performed to assess agreement between T_C and T_C-est. A systematic bias &lt;0.1 °C was considered acceptable.</div></div><div><h3>Results</h3><div>18 participants (56 ± 16 years, 11 males) walked for 549 min (range 418–645 min), while ambient temperature increased from 22 °C to 29 °C. Average HR was 108 ± 13 bpm and T_C ranged from 36.9 to 39.2 °C, whereas T_C-est ranged from 36.8 to 38.9 °C (n = 8572 observations). Group level data revealed a systematic bias of 0.09 °C (p &lt; 0.001) with limits of agreements of ±0.44 °C. A weak correlation was found between T_C and T_C-est (r = 0.28; p &lt; 0.001). Large inter-individual differences in bias (range −0.45 °C to 0.62 °C) and correlation coefficients (range −0.09 to 0.95) were found, while only 3 participants (17%) had an acceptable systemic bias of &lt;0.1 °C.</div></div><div><h3>Conclusion</h3><div>Group level data showed that the ECTemp™ algorithm had an acceptable systematic bias during prolonged walking exercise in warm ambient conditions, but only 3 out of 18 participants had an acceptable systemic bias. Future studies are needed to improve the accuracy of the algorithm before individual users can rely on their estimated T_C during real-world exercise.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142391518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combined effects of thermal environment and gene regulation on metabolic enzyme activities of major metabolic tissues in a winter-breeding amphibian","authors":"Chi-Ying Zhang ,&nbsp;Hua-Li Hu ,&nbsp;Yu Wang ,&nbsp;Lin Zhang ,&nbsp;Guo-Hua Ding","doi":"10.1016/j.jtherbio.2024.104000","DOIUrl":"10.1016/j.jtherbio.2024.104000","url":null,"abstract":"<div><div>Variations in thermal environments can provoke diverse physiological responses in amphibians. Despite extensive studies on the thermal sensitivity of amphibian metabolic physiology, including enzyme activity at different temperatures, the rationale for selecting specific metabolic enzymes and their relationship with gene expression remains unclear. Cytochrome <em>c</em> oxidase (CCO), succinate dehydrogenase (SDH), and lactate dehydrogenase (LDH) are key metabolic enzymes within the primary metabolic regulatory tissues of animals. Through a comparative analysis of the effects of two different thermal conditions (12 and 18 °C) on the activities and mRNA expression levels of these enzymes within the kidney and liver tissues of a winter-breeding amphibian (<em>Leptobrachium liui</em>), with the field group during the breeding season as the control, we provide insights into the interplay between temperature and gene expression. The mRNA levels of CCO subunits 1 (<em>cox1</em>), 2 (<em>cox2</em>), and 3 (<em>cox3</em>), and LDH subunit A (<em>ldha</em>) were significantly higher in the kidney than in the liver of all individuals. High-temperature acclimation resulted in significantly decreased expression levels of <em>cox1</em>-<em>3</em>, <em>ldha</em>, and SDH complex flavoprotein subunit A (<em>sdha</em>) in the kidney. In the liver, the expression levels of <em>sdha</em> and <em>ldha</em> significantly reduced under high-temperature treatment, whereas <em>cox3</em> expression increased. SDH and LDH activities displayed tissue-specific variations, while no significant differences in CCO activity were observed between tissues. CCO, SDH, and LDH activities in both liver and kidney tissues significantly declined after high-temperature acclimation, but simultaneously increased with up-regulated gene expression, indicating that the thermal environment and corresponding gene expression combined affect the activities of these metabolic enzymes. In conclusion, the thermal environment is a key factor affecting the physiological and biochemical responses of <em>L. liui</em>. Prolonged exposure to high temperatures during the breeding season could inhibit the activity of primary metabolic enzymes in the winter-breeding amphibian.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142569040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of metal oxide ferrites in the process of magnetic hyperthermia – A review","authors":"Santhiya R,&nbsp;A. Ruban Kumar","doi":"10.1016/j.jtherbio.2024.103936","DOIUrl":"10.1016/j.jtherbio.2024.103936","url":null,"abstract":"<div><div>Extensive research has been conducted on the manufacturing of nano ferrites, and their use in magnetic hyperthermia therapy has shown promising results in cancer treatment. This study aims primarily to provide an overview of the latest developments in the synthesis of magnetic nanoparticles (MNPs) for the treatment of hyperthermia. Magnetic nanoparticles are biocompatible and have a stable magnetic state, nano ferrites have become recognized as apex thermoseeds in biomedical applications, specifically for the treatment of magnetic hyperthermia. Employing dopant materials, biocompatible overlay, and preparation techniques, one may study the effectiveness of nano ferrites. Furthermore, specific requirements need to be met for using nano ferrites in cancer treatments like magnetic hyperthermia. These include low toxicity, biocompatibility, a higher specific absorption rate, a shorter time to reach the targeted hyperthermia temperature, crystalline size within the biological radius, and a lower dose of the nano ferrite. A potential resolution involves identifying the limitations and proposing enhanced nanocomposite materials that amplify their magnetic characteristics via a biocompatible overlay, all while optimizing the effectiveness and functioning of magnetic nanoferrites. To increase the effectiveness of ferrite nanoparticles in treating hyperthermia, this study will figure out their constraints and offer solutions for more effective ferrite-based nanocomposites that may prove to be a viable therapy option for cancer in the future.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142546181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Profiling the dynamic variations in body and scrotal surface temperatures of goats reared under stressful conditions using infrared thermography: Analytical perspectives","authors":"Emad M. Samara","doi":"10.1016/j.jtherbio.2024.103960","DOIUrl":"10.1016/j.jtherbio.2024.103960","url":null,"abstract":"<div><div>Infrared thermography (IRT) is an essential non-invasive method for analyzing surface temperature variations in animals, offering valuable insights into livestock stress responses. Despite their resilience, goats can face significant challenges under extreme conditions like heat-stress and water deprivation. This experiment aimed to delineate the dynamic variations in whole-body and scrotal surface temperatures in goats subjected to the combined impact of both conditions using IRT. Eight healthy Aardi bucks were exposed to three 72-h treatments: euhydration, dehydration, and rehydration. Continuous meteorological monitoring provided ambient-temperature, relative-humidity, and temperature-humidity index (THI) values. Surface temperatures were measured twice daily at 08:00 and 15:00, and thermal gradients between ambient and body or scrotal surface temperatures were computed. Based on the obtained mean THI values, the bucks experienced heat-stress throughout the experiment. Additionally, results revealed noticeable variations in both surface temperatures across treatments and time points, indicated by measures of central tendency, variability, shape descriptors, and frequency distribution of temperature. Morning measurements indicated lower temperatures and gradients under euhydration, while water deprivation led to higher temperatures and compromised thermal regulation. Conversely, afternoon data showed higher variability in temperature responses, highlighting the compounded effect of diurnal heat-stress and water deprivation. Although water-restoration mitigated some effects of deprivation, it did not fully restore thermal homeostasis to euhydrated levels. Thermal gradients further emphasized the goats' dynamic thermoregulatory mechanisms, which were compromised under water deprivation, particularly in the scrotal region, but were partially restored upon restoration. These findings demonstrate the effectiveness of IRT in assessing thermal responses in goats and underscore the importance of adequate hydration for maintaining thermal balance under heat-stress. The herein performed profiling provides valuable insights with implications for overall health, reproductive efficiency, productivity, and welfare in heat-stressed and water-deprived goats, which might offer a framework for future research on livestock adaptation to such challenging environmental conditions.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Upper thermal limits are ‘hard-wired’ across body mass but not populations of an estuarine fish","authors":"Daniel F. Gomez Isaza ,&nbsp;Essie M. Rodgers","doi":"10.1016/j.jtherbio.2024.103970","DOIUrl":"10.1016/j.jtherbio.2024.103970","url":null,"abstract":"<div><div>Climate warming is seeing temperatures breach exceptional thresholds as the frequency and intensity of heat waves increase. Efforts to forecast species vulnerability to climate warming often focus on upper thermal limits threatening survival, overlooking the role of intraspecific variation in determining vulnerability. Using an estuarine fish (black bream, <em>Acanthopagrus butcheri</em>) as a model, we explore how intraspecific variation in body mass and among populations affects upper thermal tolerance. Upper thermal limits were quantified using critical thermal maxima (CTmax) of wild fish. We used a ∼500 g (mean = 52.4 g, range = 0.57–541 g) mass range to test the relationship between body mass and thermal tolerance. Four distinct black bream populations were chosen along a 5° latitudinal cline to explore population differences in thermal limits. Contrary to expectations, there was no effect of body mass on upper thermal limits. However, significant population differences in thermal tolerance were observed that correlate with mean habitat temperatures. Specifically, the southern population had a significantly lower CTmax (35.57 ± 0.43 °C) compared to northern (36.32 ± 0.70 °C) and mid-latitude (36.36 ± 1.15 °C) populations. These data underscore the importance of observing intraspecific variation in thermal limits to reveal the capabilities of individuals within a species to cope with climate warming and improve the management of at-risk life stages and populations.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0306456524001888/pdfft?md5=8b02bcb0d490a9fa0c4e78a14b5ef6f8&pid=1-s2.0-S0306456524001888-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142308044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Embryonic thermal manipulation and post-hatch dietary guanidinoacetic acid supplementation alleviated chronic heat stress impact on broiler chickens","authors":"Gholamreza Zaboli ,&nbsp;Enayat Rahmatnejad","doi":"10.1016/j.jtherbio.2024.103976","DOIUrl":"10.1016/j.jtherbio.2024.103976","url":null,"abstract":"<div><p>The study investigated the effects of embryonic thermal manipulation (<strong>TM</strong>) and post-hatch guanidinoacetic acid (<strong>GAA</strong>) supplementation on male broiler chickens exposed to chronic heat stress (HS). Ross 308 eggs (n = 710) were randomly assigned to control (37.8 °C, 56% RH) or TM (39.5 °C, 65% RH for 12 h/day from embryonic day 7–16) treatments. After hatching, chicks were further assigned to four dietary treatments (n = 12 birds/pen, 5 replicates/treatment): control, control with 1.2 g/kg GAA supplementation (<strong>CS</strong>), TM, and TM with 1.2 g/kg GAA supplementation (<strong>TMS</strong>). All birds were subjected to chronic HS (32–36 °C and 55% RH for 6 h/day) from day 28–42. Embryonic TM treatment decreased hatchability, hatching weight (<strong>HW</strong>), and facial temperature (<strong>FT</strong>). During the pre-HS period (days 1–28), no significant differences in feed conversion ratio (<strong>FCR</strong>) and mortality were observed, although the TM group exhibited the lowest body weight gain (<strong>BWG</strong>). Following HS exposure (days 29–42), the TMS group displayed significantly higher BWG than the control and CS groups. The TM and TMS groups also demonstrated significantly lower FCR and mortality rates during this period. Across the entire period (days 1–42), BWG was significantly higher in the TMS group compared to other groups. Furthermore, TM and TMS treatments were associated with lower mortality rates, improved FCR, better European Performance Efficiency Index (<strong>EPEI</strong>), and reduced abdominal fat deposition. The experimental treatments did not significantly affect intestinal morphology or most blood parameters, except triiodothyronine (<strong>T3</strong>), thyroxine (<strong>T4</strong>), and uric acid. Plasma concentrations of T3, T4, and uric acid were significantly lower in the TM and TMS groups compared to the control and CS treatments. The findings suggest that a combined strategy of embryonic TM and post-hatch dietary GAA supplementation may not only alleviate the detrimental effects of HS but also promote beneficial physiological responses in broiler chickens.</p></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142274260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}