Journal of thermal biology最新文献

{"title":"Body size influences the capacity to cope with extreme cold or hot temperatures in the striped hamster","authors":"Chenxiao Hu,&nbsp;Ruihan Zhang,&nbsp;Wenting Zhang,&nbsp;Yuxin Zheng,&nbsp;Jing Cao,&nbsp;Zhijun Zhao","doi":"10.1016/j.jtherbio.2024.104008","DOIUrl":"10.1016/j.jtherbio.2024.104008","url":null,"abstract":"<div><div>Body size of organisms is a key trait influencing nearly all aspects of their life history. Despite growing evidence of Bergmann's rule, there is considerably less known about the links between body size and the maximum capacity to thermoregulate of an animal in response to extreme cold or hot environment. Thermal characteristics such as resting metabolic rate (RMR) and non-shivering thermogenesis (NST), and the upper- and lower-critical temperatures of the thermal neutral zone (TNZ) were investigated in small and large body sized striped hamsters (<em>Cricetulus barabensis</em>). The maximum capacity to thermoregulate in response to extreme cold (−15 °C) or hot temperature (38 °C) was also examined, where both, different sized hamsters had similar RMR and NST regardless of temperature exposure. The large hamsters had 29.9% more body mass compared to small hamsters. The large hamsters showed a wider TNZ, with lower, lower-critical temperature, and showed considerable hyperthermia at the end of a 17-h hot exposure. In contrast, the small hamsters showed hypothermia following a 17-h cold exposure relative to large hamsters. In addition, the large hamsters showed 17.2% lower basal thermal conductance, and 14.9% lower maximum thermal conductance than the small hamsters after cold exposure, and 22.6% lower thermal conductance following heat exposure. Several molecular markers indicative of thermogenesis and oxidative stress did not differ significantly between the large and small hamsters. These findings suggest that individuals with larger body sizes have greater capacity to thermoregulate to cope with extreme cold, and a reduced capacity in response to extreme hot. In contrast, smaller individuals demonstrated the opposite trend. Body size may decide the capacity to thermoregulate to cope with extreme cold and heat, within which body heat dissipation is likely more important than heat production.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"126 ","pages":"Article 104008"},"PeriodicalIF":2.9,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142785986","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":"Age and mating status have complex but modest effects on the critical thermal limits of adult Mediterranean fruit flies from geographically divergent populations","authors":"Antonis G. Papadopoulos ,&nbsp;Panagiota Koskinioti ,&nbsp;Kostas D. Zarpas ,&nbsp;Paraschos Prekas ,&nbsp;John S. Terblanche ,&nbsp;Daniel A. Hahn ,&nbsp;Nikos T. Papadopoulos","doi":"10.1016/j.jtherbio.2024.104013","DOIUrl":"10.1016/j.jtherbio.2024.104013","url":null,"abstract":"<div><div>The highly invasive Mediterranean fruit fly (medfly), <em>Ceratitis capitata</em> (Wiedemann) (Diptera: Tephritidae), is currently expanding its geographic distribution into cooler temperate areas of the Northern Hemisphere. In marginal conditions, the invasion potential of medfly depends in part on innate tolerance to the novel environmental conditions. Physiological tolerances are potentially influenced by interactions among multiple factors, such as organism age or reproductive maturity, sex, and mating status. Furthermore, the relationships between the above factors and tolerances may differ among geographically distinct populations. Here, the effects of age and mating status on thermal tolerance of three geographically distinct medfly populations along a latitudinal gradient ranging from Greece (Crete &amp; Volos) to Croatia (Dubrovnik) were examined. The upper and lower critical thermal limits (scored as loss of neuromuscular function during controlled cooling or heating) of adult males and females (a) at 1-, 6-, 15-, and 35 days old and of (b) both mated and virgin flies were assessed. Results showed that estimates of lower and upper thermal limits (CTmin and CTmax) were both population- and age-dependent. In most age classes tested, CTmin values were lower for the adults obtained from Crete and higher for those from Dubrovnik. CTmax values were lower for the females from Dubrovnik compared to the females from any other population on day one after emergence but not on days 6, 15 and 35. Differences among populations were observed across different age classes both for cold and heat tolerance but mostly in CTmin estimates. Mating status had a little effect on cold and heat tolerance. Complex patterns of thermal limit variation within and among populations suggest a suite of factors determine population-level mortality from thermal extremes under field conditions in medfly. These results contribute towards understanding the invasion dynamics of medfly and its range expansion to northern, more temperate regions of Europe.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"126 ","pages":"Article 104013"},"PeriodicalIF":2.9,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142716505","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":"Searching for variables representing the response to cold stress in mediterranean Geotrupinae reveals an association between heat and cold tolerances","authors":"Belén Gallego ,&nbsp;José R. Verdú ,&nbsp;Yolanda Jiménez-Ruiz ,&nbsp;Jorge M. Lobo","doi":"10.1016/j.jtherbio.2024.103997","DOIUrl":"10.1016/j.jtherbio.2024.103997","url":null,"abstract":"<div><div>The study of cold tolerance is imperative for understanding insect activity across spatial and temporal gradients. Here, we assessed various physiological variables to discern the response to cold stress in Mediterranean earth-boring dung beetles, utilizing an infrared thermography protocol initially developed for detecting heat stress variables.</div><div>Subsequently, we conducted a joint analysis of heat and cold stress variables to explore the extent of congruence between their responses. Our findings indicate that the temperatures at which activity ceases and resumes are the most effective variables for distinguishing between the cold thermal strategies of the studied species. Moreover, our analyses revealed a positive association between the variables representing heat and cold tolerances, wherein species with higher upper limits of heat tolerance also exhibit higher temperatures at which they become immobilized by cold.</div><div>This result suggest that adaptations to endure heat may compromise resistance to cold in these insects. We hypothesize about the main factors (loss of wings, fusion of the elytra, and accumulation of haemolymph) that could have represented radical modifications in the Mediterranean clades of Geotrupinae. These factors may have reshaped their life history and thermal physiology, potentially impairing thermogenesis, reducing cold hardiness and freezing resistance.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"126 ","pages":"Article 103997"},"PeriodicalIF":2.9,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142692928","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":"The repeatability of a cycling exercise-heat stress test in a male population","authors":"Jake Shaw ,&nbsp;Cole E. ,&nbsp;Andrew J. Simpson ,&nbsp;Christopher J. Tyler ,&nbsp;Andrew T. Garrett","doi":"10.1016/j.jtherbio.2024.103983","DOIUrl":"10.1016/j.jtherbio.2024.103983","url":null,"abstract":"<div><h3>Introduction</h3><div>There is considerable inter-individual variability in the physiological responses to environmental stressors and so to accurately assess and monitor changes in an individual's ability to cope with exercise-heat stress, a reliable protocol is required. The aim of this study was to examine the repeatability of a 90-min steady-state heat exercise bout with physiological and subjective variables, and performance during an incremental test to exhaustion post 90-min steady-state exercise.</div></div><div><h3>Method</h3><div>Sixteen mixed ability males (Age: 39 ± 15yrs; Height: 176.5 ± 4.8 cm; BM: 79.7 ± 10.3 kg; <span><math><mrow><mover><mi>V</mi><mo>˙</mo></mover></mrow></math></span>O_2peak: 46.2 ± 8.6 ml/kg/min; PPO: 309 ± 39W) who trained at least three times a week undertook two 90-min steady-state – followed by an incremental protocol to exhaustion – cycling heat stress tests (HSTs) in a hot-humid environment (35 °C, 60%RH). Heart rate (HR), rectal (<span><math><mrow><mover><mi>T</mi><mo>‾</mo></mover></mrow></math></span> <em>r</em>_<em>e</em>) and skin temperature (<span><math><mrow><mover><mi>T</mi><mo>‾</mo></mover></mrow></math></span>_<em>sk</em>), rating of perceived exertion (RPE), thermal sensation (TS), and thermal comfort (TC) were measured throughout<strong>.</strong> Data was analysed using Intraclass Correlation Coefficients (ICC), technical error of measurement (TEM), Bland-Altman plots, <em>t</em>-tests, and Cohen's <em>d</em> to indicate magnitude of change.</div></div><div><h3>Results</h3><div>Physiological variables indicated good repeatability evident through moderate to strong ICC ratings, low magnitudes of change (<em>d</em>), lower mean biases compared to their respective calculated TEMs, and statistical non-significance, except HR90, ₸_<em>sk</em>90, and ₸_<em>sk</em>. Hydration status showed good repeatability except for urine osmolality (osm_u90) and resting urine colour (col_u). Perceptual variables showed encouraging repeatability apart from resting TS and mean TS. Performance data showed good repeatability overall, however 11 participants progressed to the incremental test to exhaustion in the second visit compared to 7 in the first.</div></div><div><h3>Conclusion</h3><div>Current data demonstrated favourable physiological, perceptual, and performance repeatability during repeated cycling HSTs in hot-humid conditions. However, given more participants progressed to the incremental trial to exhaustion protocol in the second visit, at least one familiarisation trial may improve the reliability of exercise capacity assessment.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"125 ","pages":"Article 103983"},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142577773","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":"A potential trade-off between reproduction and enhancement of thermotolerance in Liriomyza trifolii populations driven by thermal acclimation","authors":"Yu-Cheng Wang ,&nbsp;Ya-Wen Chang ,&nbsp;Fei Yang ,&nbsp;Wei-Rong Gong ,&nbsp;Jie Hu ,&nbsp;Yu-Zhou Du","doi":"10.1016/j.jtherbio.2024.103988","DOIUrl":"10.1016/j.jtherbio.2024.103988","url":null,"abstract":"<div><div>The invasive pest, <em>Liriomyza trifolii</em>, poses a significant threat to ornamental and vegetable plants. It spreads rapidly and causes large-scale outbreaks with pronounced thermotolerance. In this study, we developed <em>L. trifolii</em> strains adapted to high temperatures (strains designated 35 and 40); these were generated from a susceptible strain (designated S) by long-term thermal acclimation to 35 °C and 40 °C, respectively. Age-stage, two-sex life tables, thermal preferences, critical thermal limits, knockdown behaviors, eclosion and survival rates as well as expression of genes encoding heat shock proteins (<em>Hsps</em>) were compared for the three strains. Our findings indicated that the thermotolerance of <em>L. trifolii</em> was enhanced after long-term thermal acclimation, which suggested an adaptive plastic response to thermal stress. A trade-off between reproduction and thermotolerance was observed under thermal stress, potentially improving survival of the population and fostering adaptionary changes. Acclimation at 35 °C improved reproductive performance and population density of <em>L. trifolii</em>, particularly by enhancing the fecundity of female adults and accelerating the speed of development. Although the 40 strain exhibited the highest developmental speed and greater thermotolerance, it incurred a larger reproductive cost. This study provides a theoretical framework for monitoring and controlling leafminers and understanding their evolutionary adaptation to environmental changes.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"125 ","pages":"Article 103988"},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142375622","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":"Effect of egg incubator temperature on sex differentiation in Korat chickens","authors":"Chanoknan Khamoun ,&nbsp;Sajeera Kupittayanant ,&nbsp;Pakanit Kupittayanant","doi":"10.1016/j.jtherbio.2024.103984","DOIUrl":"10.1016/j.jtherbio.2024.103984","url":null,"abstract":"<div><div>The effect of incubator temperature on sex differentiation in Korat chickens was investigated. The experiments were divided into two sets: temperature applied throughout the entire incubation period and temperature applied during certain periods (days 3–6 of incubation) by either increasing above the standard or decreasing below the standard temperature. In each experiment, 300 Korat chicken eggs were separated into three groups of 5 repetitions, with 20 eggs in each group. This was done using a completely randomized design for each experiment: a group using a temperature below the standard for incubation (36.0 °C), a group using the standard incubation temperature (37.7 °C), and a group using a temperature above the standard for incubation (38.0 °C). W chromosomes were detected at hatch; histology examined reproductive structures after 35 days. Increasing the temperature to 38.0 °C throughout the entire incubation period resulted in no significant difference in hatching rates compared to the standard temperature (P &gt; 0.05). Raising the temperature to 38.0 °C throughout the entire incubation and during certain periods resulted in changes in the reproductive structure of chickens, leading to a mismatch between chromosomal and gonadal sex, observed at 9.7% and 5.9% of individuals with W chromosomes possessed testes, indicating a mismatch between chromosomal and gonadal sex. However, decreasing the temperature to 36.0 °C throughout the incubation period resulted in lower hatching rates compared to the standard temperature (P &lt; 0.05). Incubating eggs at 36.0 °C for specific periods resulted in 19.4% of genetic males developing ovaries instead of testes. The presence of ovaries in individuals without W chromosomes indicated this mismatch. The results of this study provide evidence that temperature plays a role in sex differentiation in Korat chickens, as demonstrated by the detection of W chromosomes and histological studies of testes and ovaries. Moreover, this study presents the first evidence in broilers that temperature can affect sex differentiation.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"125 ","pages":"Article 103984"},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358132","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":"Non-evaporative heat dissipation across the beaks and casques of large forest hornbills","authors":"Bianca Coulson ,&nbsp;Marc T. Freeman ,&nbsp;Juanita Wessels ,&nbsp;Andrew E. McKechnie","doi":"10.1016/j.jtherbio.2024.103993","DOIUrl":"10.1016/j.jtherbio.2024.103993","url":null,"abstract":"<div><div>Heat loss across the beak is an important thermoregulatory mechanism among birds, particularly in large-beaked taxa such as toucans (Ramphastidae) and hornbills (Bucerotidae). The number of species investigated remains limited, as does our understanding of how the functional significance of this pathway varies with environmental variables such as humidity, with little previous research on species inhabiting humid environments. We used infrared thermography to test the hypothesis that large (600–1300 g) Afrotropical forest hornbills use their beaks and casques as thermal radiators. We collected data over air temperatures (<em>T</em>_air) of 15–34 °C for wild-caught trumpeter hornbills (<em>Bycanistes buc</em><em>inator</em>) and captive-bred silvery-cheeked hornbills (<em>Bycanistes brevis</em>) and black-casqued hornbills (<em>Ceratogymna atrata</em>). Surface temperatures of the beaks and casques (<em>T</em>_beak) tracked <em>T</em>_air below 24–25 °C, but at higher <em>T</em>_air, the <em>T</em>_beak – <em>T</em>_air gradient increased to maximum values of 10–12 °C. Maximum rates of beak heat loss were 2.5–3.8 W, equivalent to 31–83 % of estimated resting metabolic heat production. Facial skin showed also evidence for active regulation of heat loss. We also analysed the scaling of the inflection <em>T</em>_air above which the <em>T</em>_beak – <em>T</em>_air gradient increases (<em>T</em>_inflection) by combining our data with published and three unpublished values. We found that <em>T</em>_inflection decreases with increasing body mass (<em>M</em>_b), with the relationship best described by the linear regression model <em>T</em>_inflection = −9.134log₁₀<em>M</em>_b + 50.83, with <em>M</em>_b in g.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"125 ","pages":"Article 103993"},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142468719","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":"Effects of temperature on fish aggression and the combined impact of temperature and turbidity on thermal tolerance","authors":"Erin K. Francispillai,&nbsp;Sixtine M. Dietsch,&nbsp;Lauren J. Chapman","doi":"10.1016/j.jtherbio.2024.103987","DOIUrl":"10.1016/j.jtherbio.2024.103987","url":null,"abstract":"<div><div>Deforestation can increase light penetration and runoff entering adjacent freshwaters leading to increased average water temperature, stronger diel temperature fluctuations, and increased water turbidity. Changes in temperature extremes (particularly upper peaks) are important for fishes as their body temperature and rate of oxygen consumption varies with environmental temperature. Here, we compare effects of diel-fluctuating versus stable water temperature regimes on the behaviour and upper thermal tolerance (measured as Critical Thermal Maximum, CT_max) of the Bluntnose Minnow, <em>Pimephales notatus</em>. Fish were acclimated to either a static 18°C, static 24°C or a diel-fluctuating treatment of low to high (18-24°C) for a total of 10 weeks. Activity level and aggression were measured for 6 consecutive weeks during the acclimation period. Activity level remained high across treatments and over time. However, fish from the diel-fluctuating treatment exhibited a significant increase in aggression over the day as temperatures increased from 18°C to 24°C. Following acclimation, upper thermal limits of fish from each treatment were measured under two conditions: clear water (&lt;2 NTU) and turbid water (25 NTU). This was to evaluate effects of acute turbidity exposure that might arise with heavy rain on deforested streams. CT_max was lowest in fish acclimated to static 18°C and highest in fish acclimated to static 24°C; fish acclimated to diel 18-24°C showed an intermediate CT_max. Exposure to acute turbidity during CT_max trials significantly lowered CT_max across all treatments, highlighting the importance of multiple-stressor studies in evaluating upper thermal tolerance of fishes.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"125 ","pages":"Article 103987"},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423327","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":"Seasonal and between-population variation in heat tolerance and cooling efficiency in a Mediterranean songbird","authors":"Julián Cabello-Vergel ,&nbsp;Jorge S. Gutiérrez ,&nbsp;Erick González-Medina ,&nbsp;Juan M. Sánchez-Guzmán ,&nbsp;José A. Masero ,&nbsp;Auxiliadora Villegas","doi":"10.1016/j.jtherbio.2024.103977","DOIUrl":"10.1016/j.jtherbio.2024.103977","url":null,"abstract":"<div><div>Discrete populations of widely distributed species may inhabit areas with marked differences in climatic conditions across geographic and seasonal scales, which could result in intraspecific variation in thermal physiology reflecting genetic adaptation, phenotypic plasticity, or both. However, few studies have evaluated inter-population variation in physiological responses to heat. We evaluated within- and inter-population seasonal variation in heat tolerance, cooling efficiency and other key thermoregulatory traits in two Mediterranean populations of Great tit <em>Parus major</em> experiencing contrasting thermal environments: a lowland population subject to hotter summers and a higher annual thermal amplitude than a montane population. Specifically, we measured heat tolerance limits (HTL), body temperature, resting metabolic rate, evaporative water loss, and evaporative cooling efficiency (the ratio between evaporative heat loss to metabolic heat production) within and above the thermoneutral zone during winter and summer. Heat tolerance during summer was greater in lowland than in montane birds; indeed, lowland birds seasonally increased this trait to a significant level, while montane ones did to a lesser extent. Besides, lowland birds showed greater evaporative cooling efficiency during summer (possibly due in part to reductions in total endogenous heat load), while surprisingly montane ones showed the opposite trend. Thus, lowland birds displayed greater seasonal flexibility in HTL, body temperature and resting metabolic rate above thermoneutrality, thus giving some support to the climatic variability hypothesis — that flexibility in thermoregulatory traits should increase with climatic variability. Our results partially support the idea that songbirds’ adaptive thermoregulation in the heat is flexible, highlighting the importance of considering intraspecific variation in thermoregulatory traits when modelling the future distribution and persistence of species under different climate change scenarios.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"125 ","pages":"Article 103977"},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358175","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":"Morphological adaptation to environmental stress in small ruminants from the sahelian zones of Niger and potential associations with carcass yield","authors":"Ibrahim Adamou Karimou ,&nbsp;Hassane Yaye Abdou ,&nbsp;Issoufou Guero Chekaraou ,&nbsp;Moumouni Issa","doi":"10.1016/j.jtherbio.2024.103986","DOIUrl":"10.1016/j.jtherbio.2024.103986","url":null,"abstract":"<div><div>This study analyses, in the Sahelian zone of Niger, the morphological traits of sheep and goats' responses to environmental stress and the contribution of adaptive traits to herd productivity. The study utilized 2490 adult small ruminants, including 653 red and Sahelian goats and 1837 Peulh (with three varieties: Balami, Oudah and Bali-Bali) and Tuareg (Ara-ara) sheep from 13 sites with a marked aridity gradient within the country's northern latitude. Carcass yield was assessed on a second sample of 1617 adult animals, comprising 876 sheep and 741 goats. Variations in thorax auricular index (ratio of ear length to thorax depth), gracility index (which reflects the subtraction of the animal's body from the ground) and hot carcass yield, according to climate zones and breed, were subjected to an analysis of variance at the 5% risk threshold. Principal Component Analysis was used to analyze correlations between biometric and heat indices. For most breeds, the auricular thorax index and the gracility index were higher for animals in arid zones than those in humid zones. The increase in the average values of the body indices had as a result an increase in the animals' carcass yield and live weight. In all sheep and goat breeds, gracility increases with heat index. Gracility differed (p &lt; 0.05) between breeds, with Bali-Bali and Oudah subgenetics of the Peulh sheep breed being more gracile than the Ara-ara sheep. Also, the auricular thorax index was higher (p &lt; 0.05) in Sahelian goat than in red goat. The importance of biometric indices in terms of animals' adaptability to their environment means that we need to define important heat stress indicators specific to sheep and goats in Sahelian farming systems.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":"125 ","pages":"Article 103986"},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142406568","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}