Journal of thermal biology最新文献

{"title":"Effect of habitat use and coadaptive responses on the thermal physiology of two related species of lizards living in high mountain environments","authors":"A. Bautista-del Moral ,&nbsp;D.M. Arenas–Moreno ,&nbsp;F.R. Méndez-de la Cruz","doi":"10.1016/j.jtherbio.2025.104275","DOIUrl":"10.1016/j.jtherbio.2025.104275","url":null,"abstract":"<div><div>Coadaptation processes evolve when the interaction among behavior, physiology, and morphology produces positive effects on the fitness of organisms. In this context, the coadaptation of thermal physiology and behavioral thermoregulation strategies in ectothermic organisms should be prominent, mainly due to their thermal dependence and the influence of body temperatures on physiological performance, ecological interactions, and fitness. Therefore, we aimed to investigate the role of microhabitat use in two high-mountain lizard species (<em>Abronia</em> genus) with different habitat preferences (terrestrial and arboreal) on the degree of coadaptation between thermal physiological parameters and thermoregulatory strategies. We found that environmental pressures, driven by habitat use and seasonality, result in differential responses in both behavioral thermoregulation strategies and the physiology of these species. This high response capacity has allowed them to compensate for thermal fluctuations in their microhabitats and has, to some extent, promoted the coadaptation of selected temperature (<em>T_sel</em>), thermal optimum (<em>T_o</em>), and thermal performance breadth (B₈₅), along with thermal limits and thermoregulatory strategies. Our findings support the hypothesis of labile physiology, as both <em>Abronia</em> species responded to divergent thermal regimes by adapting their thermal physiology.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"133 ","pages":"Article 104275"},"PeriodicalIF":2.9,"publicationDate":"2025-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145156452","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 skeletal muscle vasodilatory pathway in adaptive thermogenesis in Sunit Mongolian sheep","authors":"F.H. Meng ,&nbsp;L. Wang ,&nbsp;T. Zhou ,&nbsp;L.W. Chang ,&nbsp;Y.Y. Zi ,&nbsp;R.N. Su ,&nbsp;M. Zhao ,&nbsp;X.Y. Zhou ,&nbsp;D. Zhang ,&nbsp;W.G. Zhang ,&nbsp;C.X. Liu","doi":"10.1016/j.jtherbio.2025.104278","DOIUrl":"10.1016/j.jtherbio.2025.104278","url":null,"abstract":"<div><div>The Sunite Mongolian sheep is one of the superior livestock breeds in Inner Mongolia, capable of surviving and reproducing on the Xilingol Grassland at temperatures below −30 °C, demonstrating remarkable cold adaptation. However, research on adaptive thermogenesis in its muscle tissue remains limited. To investigate skeletal muscle's role in adaptive thermogenesis, shoulder muscle tissues were collected from three healthy castrated male sheep each in winter (January) and summer (July) for RNA sequencing (RNA-seq) and differential expression analysis. Differentially expressed genes (DEGs) were primarily enriched in pathways associated with starvation response, hormonal regulation, and energy metabolism. Gene expression analysis revealed significant upregulation of nitric oxide synthase 3 (<em>NOS3</em>) and adrenergic receptor-β2 (ADRB2) in the adrenergic-cyclic guanosine monophosphate (cGMP)- protein kinase G(PKG)vasodilatory signaling pathway during winter (<em>P</em> &lt; 0.01). Further validation showed that ADRB2 was extensively expressed in skeletal muscle vascular endothelial cells, with significantly increased winter expression. Subsequent in vivo experiments confirmed these results, intravenous injection of isoproterenol (ISO) dose-dependently increased cGMP concentration and <em>NOS3</em> expression (<em>P</em> &lt; 0.05). In summary, we speculate that epinephrine binds to ADRB2 in the skeletal muscle of Sunite Mongolian sheep during winter, activating intracellular <em>NOS3</em> to synthesize nitric oxide (NO). Through the cGMP-PKG signaling pathway, this induces vasodilation, thereby transporting more nutrients and enhancing metabolic energy production and heat generation, primarily via glucose metabolism, to adapt to cold environments. This study provides new insights into cold adaptation in sheep, suggesting ADRB2/NOS3 as potential molecular markers for breeding cold-resistant breeds to enhance farming efficiency.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"133 ","pages":"Article 104278"},"PeriodicalIF":2.9,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145109639","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":"Qingshu Yiqi tea prescription attenuates heat-stressed injury: network pharmacology and experimental validation","authors":"Qianyu Liu ,&nbsp;Chengdou Xie ,&nbsp;Ping Lan ,&nbsp;Yuxuan Chen ,&nbsp;Siqing Chen","doi":"10.1016/j.jtherbio.2025.104270","DOIUrl":"10.1016/j.jtherbio.2025.104270","url":null,"abstract":"<div><div>Heat stress (HS) poses a significant threat to health, necessitating effective interventions. This study investigated the therapeutic mechanisms of Qingshu Yiqi Tea Prescription (QSYQTP) against HS-induced organ damage in mice. Utilizing an integrated pharmacology approach combining histopathology, network pharmacology, biochemical assays, and qRT-PCR, we assessed QSYQTP's effects in a heat-stressed murine model. QSYQTP supplementation suppressed serum aminotransferase activities (ALT, AST), reduced MDA concentrations, and enhanced antioxidant enzymes (T-SOD, GSH). It also downregulated heat shock genes (HSP27/60/70/90) by inhibiting HSF1 expression, suggesting MAPK involvement, MAPK signaling pathway inhibition (P-JNK, P-P38). These results suggest that QSYQTP may increase the antioxidant capacity in vivo, reduce oxidative stress, and inhibit the heat shock response, all of which can help ameliorate HS-induced liver and small intestine damage.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"133 ","pages":"Article 104270"},"PeriodicalIF":2.9,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145109640","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":"Temperature alters thermal tolerance and physiological response to simulated angling in paddlefish","authors":"Shasta R. Kamara ,&nbsp;Jackson C. Glomb ,&nbsp;Cory D. Suski","doi":"10.1016/j.jtherbio.2025.104272","DOIUrl":"10.1016/j.jtherbio.2025.104272","url":null,"abstract":"<div><div>Global climate change has led to the decline of many recreational and commercial fish species. American Paddlefish (<em>Polyodon spathula</em>) support important fisheries across the United States and can experience angling and release across a range of temperatures due to current management regulations. Currently, the impact of thermal variation on paddlefish has not been defined, precluding managers from making thermally-informed decisions related to the timing and duration of angling and harvest seasons. Therefore, we quantified the response of paddlefish chased to exhaustion and air-exposed across a range of temperatures. To accomplish this, juvenile paddlefish were acclimated to 13, 17.5, and 22 °C. Fish were then subjected to a simulated angling interaction and allowed to recover for 0.5 h, 4 h, or 8 h to evaluate recovery of physiological parameters. Following exercise, recovery profiles differed among acclimation temperatures, with paddlefish acclimated to the warmest temperature (22 °C) having prolonged recovery of plasma lactate, compared to fish experiencing cooler temperatures (13.0 °C and 17.5 °C). A second group of paddlefish from each temperature was subjected to a critical thermal maximum test (CT_max). Paddlefish CT_max was influenced by acclimation temperature, but experienced an upper thermal limit, with fish gaining a small but non-significant increase in thermal tolerance when acclimated to temperatures above 17.5 °C. Together, results indicate that paddlefish experiencing warmer water temperatures have reduced performance relative to cooler fish, suggesting that angling or release at temperatures over 17.5 °C will result in an extended recovery period, and paddlefish may have limited capacity for acclimation to warmer temperatures.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"133 ","pages":"Article 104272"},"PeriodicalIF":2.9,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145091991","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":"Skin temperature thresholds: A novel non-invasive potential tool for estimating ventilatory thresholds","authors":"Xianxiang Zeng ,&nbsp;Chunxue Tang ,&nbsp;Yuxiao Deng ,&nbsp;Yanyan Zhang ,&nbsp;Lijun Shi","doi":"10.1016/j.jtherbio.2025.104256","DOIUrl":"10.1016/j.jtherbio.2025.104256","url":null,"abstract":"<div><h3>Background</h3><div>Developing non-invasive, practical methods to identify exercise metabolic thresholds remains a key focus in exercise physiology. This study examined the variation patterns of average skin temperature (aT_sk) measured by infrared thermography during a ramp incremental exercise test (RIET) and determined skin temperature thresholds (TSKTs) to assess their agreement with ventilatory thresholds (VTs).</div></div><div><h3>Methods</h3><div>Twenty-three active college students performed a RIET. Physiological parameters including aT_sk, oxygen uptake (<span><math><mover><mi>V</mi><mo>˙</mo></mover><msub><mi>O</mi><mn>2</mn></msub></math></span>), heart rate (HR), and power output (PO), were recorded. Paired-sample t-tests, Pearson correlation (<em>r</em>), Intraclass Correlation Coefficient (<em>ICC</em>) and <em>Bland-Altman</em> were used to assess the agreement between TSKTs and VTs. The TSKTs comprised the first (TSKT1) and second (TSKT2) skin temperature thresholds.</div></div><div><h3>Results</h3><div>1) aT_sk remained stable initially, then declined (TSKT1), and finally slowed or rebounded (TSKT2). 2) No significant differences were observed between VTs and TSKTs in <span><math><mover><mi>V</mi><mo>˙</mo></mover><msub><mi>O</mi><mn>2</mn></msub></math></span>, HR, or PO (<em>P</em> &gt; 0.05). 3) At the levels of absolute <span><math><mover><mi>V</mi><mo>˙</mo></mover><msub><mi>O</mi><mn>2</mn></msub></math></span> (<span><math><mover><mi>V</mi><mo>˙</mo></mover><msub><mi>O</mi><mn>2</mn></msub><mtext>ab</mtext></math></span>), relative <span><math><mover><mi>V</mi><mo>˙</mo></mover><msub><mi>O</mi><mn>2</mn></msub></math></span> (<span><math><mover><mi>V</mi><mo>˙</mo></mover><msub><mi>O</mi><mn>2</mn></msub><mtext>re</mtext></math></span>), HR and PO, TSKT1 exhibited moderate agreement with VT1, with <em>ICC</em> (0.587, 0.432, 0.430 and 0.525) and <em>r</em> &gt; 0.40 (<em>P</em> &lt; 0.05). TSKT2 showed moderate to high agreement with VT2 for <span><math><mover><mi>V</mi><mo>˙</mo></mover><msub><mi>O</mi><mn>2</mn></msub><mtext>ab</mtext></math></span> (<em>ICC</em>: 0.774, <em>r</em>: 0.778) (<em>P</em> &lt; 0.01), <span><math><mover><mi>V</mi><mo>˙</mo></mover><msub><mi>O</mi><mn>2</mn></msub></math></span> re (<em>ICC</em>: 0.433, <em>r</em>: 0.449) (<em>P</em> &lt; 0.05), and PO (<em>ICC</em>: 0.770, <em>r</em>: 0.784) (<em>P</em> &lt; 0.01), while no significant agreement and correlation was found for HR (<em>P</em> &gt; 0.05).</div></div><div><h3>Conclusion</h3><div>TSKTs identified during RIET exhibited moderate to high reliability in estimating VTs and may serve as a potential tool for VTs assessment.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"133 ","pages":"Article 104256"},"PeriodicalIF":2.9,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145081129","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":"Genetic polymorphism in the HSP90AA1 gene revealed in indigenous cattle adapted to tropical coastal climate","authors":"Kumudinee Shivankar ,&nbsp;Amiya Ranjan Sahu ,&nbsp;Gokuldas P.P ,&nbsp;Nibedita Nayak ,&nbsp;Veeranna Gowda","doi":"10.1016/j.jtherbio.2025.104273","DOIUrl":"10.1016/j.jtherbio.2025.104273","url":null,"abstract":"<div><div>Heat stress proteins are important factors in protecting the cells of animals and humans against environmental stress, leading to cellular homeostasis. Zebu cattle are well known for the prevalence of novel mutations responsible for heat tolerance. Hence, the study was carried out to identify single nucleotide polymorphisms in the heat shock protein gene (HSP90AA1) in Shweta Kapila, Sahiwal, Gir and Malnad Gidda cattle breeds adapted to hot and humid coastal climate. Blood samples were collected and genomic DNA amplified for HSP90AA1 gene using designed oligonucleotide primers and sequenced. Rectal temperature and respiration rate both were observed elevated during the hot period compared to the cold period. Sequence data of all the amplified regions of HSP90 gene was analyzed using EditSeq and SeqMan of LASERGENE software. The analysis of custom sequencing data unveiled the presence of ten novel Single Nucleotide Polymorphisms SNPs) located at g.G4733C, g.C4765A and g.A4848G in 3′ UTR; g.C1012T and g.A1209G in exon 3; g.C1300T in intron 3; g.C2245T and g.T2266G in exon 5; and g.T3814A and g.G4212T in exon 10. The identified SNPs were genotyped by PCR-RFLP (<em>Aci</em>I and <em>Hpy</em>CH4III enzymes) and Tetra-primer ARMS-PCR. Genotypic and allelic frequencies for the regions ranged between 0.094 and 0.760, and 0.2645 to 0.7355, respectively. This was the novel report of genetic variations in the HSP90AA1 gene in selected indigenous cattle breeds of India adapted to hot and humid coastal climates. Further studies with large sample sizes are needed to genotype the loci for their significant effect on thermotolerance ability in cattle.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"133 ","pages":"Article 104273"},"PeriodicalIF":2.9,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061439","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":"Thermal tolerance and metabolic scope of Sphoeroides annulatus juveniles, a fish with aquaculture potential","authors":"Ruth Garcia-Villarreal ,&nbsp;Ana Denise Re-Araujo ,&nbsp;J. Pablo Sánchez-Ovando ,&nbsp;Leonardo Ibarra-Castro ,&nbsp;Melany Sánchez-González ,&nbsp;Fernando Díaz","doi":"10.1016/j.jtherbio.2025.104274","DOIUrl":"10.1016/j.jtherbio.2025.104274","url":null,"abstract":"<div><div>Ocean warming, driven by current anthropogenic climate change, affects the physiological responses of marine ectotherms, including <em>Sphoeroides annulatus</em> (bullseye puffer fish), a fish with aquaculture potential. This subtropical-tropical fish inhabits shallow estuarine and coastal environments along the eastern Pacific and is exposed to extreme temperature fluctuations and marine heatwaves, which may threaten its distribution and cultivation. This study aimed to determine thermal tolerance (CT_max and CT_min), thermal polygon area, acclimation capacity via the acclimation response ratio (ARR), thermal safety margins (TSM), and plasticity of the thermal metabolic scope (TMS) of <em>S. annulatus</em> juveniles. Prior to experiments, juveniles (N = 300) were acclimated to five temperatures (20, 23, 26, 29, and 32 °C ± 1 °C) for 30 days. CT_max ranged from 37.8 to 41.4 °C and CT_min from 12.0 to 18.7 °C. The thermal polygon area (293.0°C²) indicated moderately eurythermal behavior, consistent with the species’ broad distribution. ARR values ranged from 0.2 to 0.4 for CT_max and 0.1 to 0.9 for CT_min, suggesting greater plasticity to cold than to warm conditions. Present and future TSM estimates suggest that <em>S. annulatus</em> populations in tropical zones may be more vulnerable to ocean warming than those in subtropical regions. The highest TMS values—an indicator of aerobic capacity—were observed in juveniles acclimated at 23–26 °C, indicating that this temperature range may represent a thermally favorable condition for maximizing aerobic performance. This study provides insight into the physiological limits of <em>S. annulatus</em> under ocean warming conditions and helps define optimal conditions to improve juvenile growth in aquaculture systems.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"133 ","pages":"Article 104274"},"PeriodicalIF":2.9,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097796","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":"Is a warmer environment better for a high-mountain lizard?","authors":"Mirna C. Vera-Chávez ,&nbsp;Donald B. Miles ,&nbsp;Diego M. Arenas-Moreno ,&nbsp;Fausto R. Méndez-de la Cruz","doi":"10.1016/j.jtherbio.2025.104265","DOIUrl":"10.1016/j.jtherbio.2025.104265","url":null,"abstract":"<div><div>The global increase in temperatures threatens the survival of lizards in habitats with broad thermal oscillations. Viviparous populations in high mountains (sky islands) often exhibit a greater thermal tolerance, a trait that, according to Janzen's Hypothesis, is favored by these environments. This raises the question of whether such an adaptation can help them cope with global warming more effectively than populations at lower elevations. To investigate this, we translocated <em>Sceloporus bicanthalis</em> from its native habitat at 4100 m (the species occupy elevations between 2500 and 4250 m) to a lower elevation of 2060 m, simulating a temperature increase. During a 45-day acclimatisation experiment, we measured thermophysiological traits and locomotor performance in pre-acclimatisation (in their native habitat) and post-acclimatisation individuals (at the lower-elevation site). Although we found no changes in thermal limits, the effectiveness of thermoregulation (<em>E</em>) was greater in the pre-acclimatisation group. Translocated individuals showed an increase in maximum sprint speed (<em>Vmax</em>), while the optimal performance temperature (<em>Topt</em>) remained constant in both groups and coincided with their preferred temperature range. Our study demonstrated that, far from being a strict thermal specialist, the thermal physiology of <em>S. bicanthalis</em> allows it to persist in habitats with warmer thermal conditions, evidencing a greater thermal tolerance and suggesting sufficient physiological plasticity to cope with increasing ambient temperatures.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"133 ","pages":"Article 104265"},"PeriodicalIF":2.9,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145061013","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":"High temperatures amplify aggressiveness of an invasive lizard toward a native congener","authors":"Julie E. Rej,&nbsp;Alex R. Gunderson","doi":"10.1016/j.jtherbio.2025.104257","DOIUrl":"10.1016/j.jtherbio.2025.104257","url":null,"abstract":"<div><div>Invasive species cause major disturbances to endemic wildlife and often displace native species. Behavioral aggression can contribute to invasive species success, but little is known about how temperature and aggression interact. We tested for effects of temperature on interspecific aggression between the invasive brown anole lizard (<em>Anolis sagrei</em>) and a native congener, the green anole (<em>A. carolinensis</em>). <em>Anolis sagrei</em> displaces <em>A. carolinensis</em> from perch sites in sympatry, which is hypothesized to result at least in part from higher levels of aggression. We tested hypotheses about the temperature-dependence of interspecific aggression across five ecologically relevant temperature regimes that span cool spring to hot summer conditions. Additionally, we tested whether the presence of <em>A. sagrei</em> disrupts <em>A. carolinensis</em> thermoregulation. The invasive <em>Anolis sagrei</em> was more aggressive than <em>A. carolinensis</em> in all temperature regimes. In addition, the difference in aggression between the species was greatest at high temperatures. In contrast, we found little evidence that <em>A. carolinensis</em> thermoregulation is affected by <em>A. sagrei</em>. Our results indicate that the effects of an invasive lizard on a native competitor may be facilitated by high levels of aggression that could be amplified with rising temperatures. Overall, our results are consistent with aggression facilitating invasive species success, and that the effect can be amplified under climate change.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"133 ","pages":"Article 104257"},"PeriodicalIF":2.9,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145086495","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":"Season and temperature-humidity index affect sperm quality and in vivo fertility of beef bulls","authors":"Larysse A. Alves ,&nbsp;Reinaldo F. Cooke ,&nbsp;Marcelo Sant’Ana Borges ,&nbsp;Fabiana F. Souza ,&nbsp;John P. Kastelic ,&nbsp;André M. Crespilho","doi":"10.1016/j.jtherbio.2025.104271","DOIUrl":"10.1016/j.jtherbio.2025.104271","url":null,"abstract":"<div><div>Increased temperature and humidity can reduce sperm quality and fertility of bulls. The objective was to evaluate effects of season and temperature-humidity index (THI) on quality of sperm collected from <em>Bos taurus, Bos indicus</em> and crossbred beef bulls and its fertility in fixed-time artificial insemination (FTAI) programs, considering season and THI at semen collection and 30 d before collection. Semen was collected and processed in Botucatu, SP, Brazil, between 2020 and 2022; there were 120 bulls from three breeds (Angus, Brangus, and Nelore). Frozen-thawed semen was used for fixed-time artificial insemination on 63 farms in southern, southeastern, and central-western Brazil, with 26,800 pregnancy records (5129 from Angus semen; 1217 from Brangus; and 20,454 from Nelore). Season and THI affected (P &lt; 0.05) sperm quality characteristics (fresh and frozen-thawed) and pregnancy rates. In summer, high THI negatively affected pre- and post-cryopreservation characteristics of Angus sperm, whereas sperm from Brangus and Nelore bulls were less affected; with high THI, sperm from Nelore bulls had the best quality, both before and after freezing. Pregnancy rates were highest with semen processed in winter (Angus and Nelore) or spring (Brangus). With semen processed in the summer or with the highest THI, Brangus and Nelore bulls had significantly higher pregnancy rates than Angus. In conclusion, Angus bulls were more sensitive to heat stress during the summer and high THI conditions, with significant reductions in fresh and post-thaw semen quality. Results were attributed to Brangus and Nelore sires being better adaptated to high THI, sustaining semen quality and fertility in all seasons under in a subtropical climate.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"133 ","pages":"Article 104271"},"PeriodicalIF":2.9,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145156453","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}