Mean Rectal Temperature Research Articles

Incidence of puerperal metritis and associated risk factors in dairy cows in Hawassa, Southern Ethiopia

Metritis has considerable economic impact on dairy herd profitability due largely to reduced reproductive performance. Studies in Ethiopia only report prevalence, with no available data on the incidence of metritis. The present prospective cohort study aimed to estimate the incidence of puerperal metritis, identify risk factors, and isolate the causative bacteria in dairy cows in Hawassa. Daily follow-up of 120 dairy cows from parturition to 21 days postpartum was carried out from November 2019 to February 2021. Of these, 21 developed puerperal metritis with an incidence rate of 0.94 cases per 100 cow days at risk (95 % CI: 0.6–1.4). The cumulative incidence was found to be 17.5 % (95 % CI: 11.8–25.6). Over 90 % of the puerperal metritis occurred within the first 10 days of parturition. The mean day of occurrence of puerperal metritis was 7.7 days postpartum and the mean rectal temperature in metritic cows was 40.5 °C. Retained fetal membranes (RFM) (p < 0.001) emerged as the only predisposing factor for metritis in the final Cox regression model. Cows with RFM faced a 14.9 times higher risk of metritis compared to cows without RFM. A total of 52 bacterial isolates, belonging to 4 genera, were recovered from the aerobic culture of 21 uterine swab samples. E. coli and Staphylococcus spp. were the most frequently isolated bacteria, with recovery from 21 (100 %) and 20 (95.2 %) of the metritic uteri, respectively. Results of this study suggested the importance of reducing incidence of RFM to reduce incidence of metritis in dairy cows.

Calculation of a Reference Interval for Rectal Temperature in Adult Dogs Presenting for Veterinary Care Using an Algorithm for Mixed Data.

Veterinarians rely on the measurement of canine body temperature to define the health status of dogs, but no studies exist defining a reference range for rectal temperature on a large group of dogs. The aim of this study was to define the rectal body temperature of dogs based on a large data set of diseased and healthy animals and to evaluate the capability of the employed algorithm to calculate reference intervals of numerical clinical data. Out of 24,013 recorded measurements, statistical analysis was applied to data from 9782 adult dogs that underwent clinical examination at a university clinic between 2008 and 2017. The reference interval was calculated using an algorithm developed by the Deutsche Gesellschaft für Klinische Chemie und Laboratoriumsmedizin e.V. as part of its Reference Limit Estimator software (version 1.40.36.07). The following values were excluded: multiple measurements in a given dog, samples without assigned age or dogs younger than one year, and values <30.0 °C and >43.0 °C. Out of 9782 adult dogs, 665 temperature measurements were identified as outliers, and 9117 were used for further statistical analysis. The mean rectal temperature was 38.6 °C (90% CI: 38.6-38.6 °C) with a reference interval of 37.7 °C (90% CI: 37.7-37.7 °C) to 39.5 °C (90% CI: 39.5-39.5 °C). Validation according to CLSI guidelines showed the results to be valid. The determination of a reference interval for rectal temperatures in dogs using an algorithm for mixed datasets yielded results comparable to the existing reference intervals. This demonstrates that the calculation of reference intervals from mixed datasets of clinical numerical data can be used to confirm existing reference intervals or establish such de novo.

Responses of Healthy Young and Older Adults to Short-Term Passive Heat Acclimation

Context: Aging is accompanied by a reduced capacity to dissipate heat. Heat acclimation has been shown to improve heat loss capacity in young healthy adults, yet few studies have investigated the capacity of older adults to adapt to repeated bouts of heat exposure, particularly when using a passive heat acclimation protocol. Furthermore, it remains unclear whether the magnitude of adaptations is affected by age. Objective and hypothesis: To compare physiological adaptations following 7 consecutive days of passive heat exposure between healthy young and older adults. We hypothesized that heat acclimation would enhance heat loss capacity in both groups but to a higher extent in young than in older adults. Methods: Fourteen healthy young (5F/9M, 27 ± 5 years) and 9 older adults (6F/3M, 66 ± 5 years) were exposed to passive heat stress with a water-perfused suit before (pre) and after (post) 7 consecutive days of immersion in 40°C water (~30 min to reach a rectal temperature of 38.5°C, followed by 60 min ≥38.5°C). During the pre/post heat stress test, mean body temperature was computed as 0.8 × esophageal temperature + 0.2 × mean skin temperature. Local sweat rate (LSR) and cutaneous vascular conductance (CVC) were measured at the forearm level. The mean body temperature onset thresholds of LSR and CVC were determined by segmented linear regression. During acclimation visits, rectal temperature and change in body mass were measured. Data are presented as means ± standard deviation or mean differences [95% confidence interval]. Results: Immersion duration (young: 90 ± 10, older: 92 ± 9 min, p=0.53), water temperature (young: 40.3 ± 0.3, older: 40.0 ± 0.5°C, p=0.09) and mean rectal temperature (young: 38.9 ± 0.1, older: 38.8 ± 0.1°C, p=0.07) during heat acclimation did not differ significantly between groups. In response to heat acclimation, rectal temperature decreased similarly ( p=0.36) in young (-0.33°C [-0.50, -0.16]) and older adults (-0.46°C [-0.68, -0.25]) from day 1 to day 7 whereas sweat rate increased to a higher extent ( p=0.05) in young (+511 mL/h [285, 738]) compared with older adults (+232 mL/h [112, 352]). Heat acclimation similarly reduced the mean body temperature onset threshold for CVC in young (-0.18°C [-0.32, -0.05]) and older adults (-0.19°C [-0.36, -0.02]) ( p=0.91), as well as, the mean body temperature onset threshold for LSR (young: -0.13°C [-0.25, -0.01], older: -0.15°C [-0.30, 0.00], p=0.84) during the pre/post heat stress test. Conclusion: These results suggest that passive heat acclimation improves heat loss capacity in young and older adults. However, age may blunt the increase in whole-body sweat rate that accompanies passive heat acclimation, but not other classical markers of human heat acclimation. Natural Sciences and Engineering Research Council of Canada. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

THE EFFECT OF DRY AND HUMID HEAT ACCLIMATION ON PERFORMANCE IN EACH ENVIRONMENT

BACKGROUND Athletes adopt heat acclimation (HA) to partly restore heat-mediated decrements in performance. However, the influence of environmental characteristics during HA on performance in dry and humid conditions is unclear. Therefore, this study aimed to compare dry and humid HA on performance in each environment. METHODS In a counterbalanced crossover study, ten trained male cyclists (age 43 ± 9 y; body mass 80.8 ± 7.3 kg; maximal oxygen uptake; 59 ± 7 mL.kg-1.min-1) completed a 30-min time-trial in hot-dry (TT-DRY; 42°C, 25% RH) and warm-humid (TT-HUM; 33°C, 80% RH) conditions before and after 8 days of controlled heart rate (HR) HA in either dry (DRY-HA) or humid conditions (HUM-HA). A Bayesian multi-level model was used to determine posterior means, 90% credible intervals, and probability of direction (%). RESULTS The improvement in power output during TT-HUM was similar following DRY-HA (13 W [3, 22]; 99%) and HUMID-HA (11 W [3, 19]; 98%). In TT-DRY, the improvement in power output was 12 W ([1, 22]; 97%) higher following DRY-HA (19 W [10, 28]; &amp;gt;99%) compared to HUM-HA (7 W [-2, 17]; 91%). During TT-HUM, mean rectal temperature changed following HUM-HA (0.03°C [-0.11, 0.17]; 63%) and DRY-HA (-0.14°C [-0.29, 0.02]; 92%), with a difference of 0.16°C ([-0.36, 0.03]; 92%). During TT-DRY, the difference was -0.20°C ([-0.40, 0.01]; 94%) between HUM-HA (-0.22°C [-0.38, -0.06]; 98%) and DRY-HA (-0.03°C [-0.19, 0.13]; 63%). Mean HR during TT-DRY (3 beats·min-1 [-2, 8]; 85%) and TT-HUM (-4 beats·min-1 [-10, 2]; 85%) was similar following DRY-HA and HUM-HA. CONCLUSIONS DRY-HA further improved mean power output during TT-DRY compared to HUM-HA. However, HUM-HA tended to lower rectal temperature more than DRY-HA during TT-DRY. HA condition did not influence HR during either TT. Our data indicate that performance is further improved in hot-dry conditions when acclimating to the same environment.

Gray–white matter contrast reversal on T1-weighted spin-echo in postmortem brain

PurposeThe image contrast of postmortem magnetic resonance imaging (MRI) may differ from that of antemortem MRI because of circulator arrest, changes in postmortem tissue, and low-body-temperature scanning conditions. In fact, we have found that the signal intensity of white matter (WM) on T1-weighted spin-echo (T1WSE) images of the postmortem brain was lower than that of gray matter (GM), which resulted in image contrast reversal between GM and WM relative to the living brain. However, the reason for this phenomenon is unclear. Therefore, the aim of this study is to clarify the reason why image contrast reversal occurs between GM and WM of the postmortem brain. Materials and methodsTwenty-three corpses were included in the study (mean age, 60.6 years; range: 19–60 years; mean rectal temperature at scan, 6.9℃; range: 4–11℃). On a 1.5 T MRI system, postmortem T1W-SE MRI of the brain was conducted in the 23 corpses prior to medico-legal autopsy. Next, T1 and T2 of the GM and WM at the level of the basal ganglia were determined in the same participants using inversion recovery and multiple SE sequences, respectively. The proton density (PD) was also calculated from the T1 and T2 images (in the same slice). ResultsT1W-SE image contrast between the GM and WM of all postmortem brains was inverted relative to the living brain. T1 (579 ms in GM and 307 ms in WM) and PD (64 in GM and 44 in WM) of the postmortem brain decreased compared with the living brain. While T1 of WM/GM remained below 1 even postmortem, the PD of WM/GM decreased. T2 (110 ms in GM and 98 ms in WM) of the postmortem brain did not differ from the living brain. ConclusionThe decrease in PD of WM/GM in the postmortem brain may be the major driver of contrast reversal between the GM and WM relative to the living brain.

Assessing Postpartum Reproductive Health via Endometrial Cytology and Body Temperature in Mehsana Buffaloes

The aim of this study was to investigate the effect of body temperature and endometrial cytology on postpartum reproductive health in Mehsana buffaloes. A total of twenty-six Mehsana buffaloes were used in this study. Per-rectal and ultrasonography examinations were used to observe the postpartum reproductive function of these buffaloes and on day 60 post natural service, the pregnancy was confirmed. Based on fertile estrus, buffaloes were retrospectively divided into two groups: Group I (buffaloes conceiving before 90 days) and Group II (buffaloes conceiving after 90 days). One week before parturition and four weeks after it, the rectal temperature was taken. The cytobrush technique was used to obtain endometrial samples for cytological tests on the 21st and 30th day postpartum. During the final week of pregnancy and the first, second, third, and fourth weeks’ post-partum, the mean rectal temperature (⁰F) varied from 101.7 ± 0.07 to 102.0 ± 0.06 in Group-I and 101.6 ± 0.07 to 102.1 ± 0.05 in Group-II. During the final week pre-partum and the first week post-partum, the mean rectal temperature (⁰F) was shown to be significantly (p&lt;0.05) lower than it was during the second, third, and fourth weeks post-partum among the groups. On the 21st and 30th day postpartum during endometrial cytology, the percentage of neutrophils was 14.31 ± 1.56 and 12.23 ± 0.93 in Group I and 17.92 ± 1.51 and 15.08 ± 0.73 in Group II, respectively. On the 30th day, there was a significant difference (p&lt;0.05) between the groups in Group II that had a greater mean percentage of neutrophils. When endometrial cytology was performed on buffaloes at various postpartum days, the mean percentage of lymphocytes, endometrial epithelial cells and large vacuolated epithelial cells revealed non-significant changes. On the 30th day, it was discovered that the prevalence of subclinical endometritis in Group I and Group II buffaloes was 7.69 and 23.07 percent, respectively. The postpartum first behavioural estrus and first fertile estrus occurred at 62.00 ± 4.34 and 65.31±4.45 days in Group I and 77.46±11.12 and 130.08±9.26 days in Group II buffaloes, respectively. Although, the average days for first behavioural estrus did not differ significantly between the groups the fertile estrus occurred significantly (P&lt;0.05) delayed in Group II buffaloes.

Performance of Goat Fed on Basal Feed and Indigofera zollingeriana

This study aimed to measure the potential and basal feed introduction (corn stover, gliricidia leaves, Panicum maximum) with the addition of Indigofera zollingeriana, which is expected to increase the goat performance. Fifteen goats aged 9-12 months, with an initial weight of ±20 kg were randomly assigned in completely randomized design (CRD) to one of three treatments and five replications. The treatment were P1 = 60% basal feed + 40% Indigofera zollingeriana, P2 = 70% basal feed + 30% Indigofera zollingeriana, P3= 80% basal feed + 20% Indigofera zollingeriana. We assessed the study outcomes as follows: daily weight gain (DWG), dry matter intake (DMI), feed efficiency and physiological responses. Data was statistically analyzed with Analysis of Variance (ANOVA) and Duncan’s multiple range test. ANOVA test showed that the treatments significantly affected (p&lt;0.05) the DMI, DWG, feed efficiency and respiratory rate. Based on multiple range tests, treatment P1 was significantly different (p&lt;0.05) than treatment P2 and P3. Mean DMI ranged from 265.8 to 380.32 g/head/day, mean DWG ranged from 33.28 to 65.62 g/head/day, mean feed efficiency ranged from 0.12 to 0.17%, mean respiratory rate ranged from 22 to 32 rate per minute. Statistical analysis showed that the treatment did not significantly (p&gt;0.05) affect rectal temperature and heart rate. Mean rectal temperature and heart rate were 38.2-39.8°C and 80-90 beats per minute, respectively. In conclusion, the administration of 60% basal feed (20% corn straw, 20% gamal leaves and 20% Panicum maximum) and 40% Indigofera zollingeriana could improve the goat’s performance.

Rectal and axillary admission temperature in preterm infants less than 32 weeks' gestation, a prospective study.

The purpose of this research was to evaluate the differences between rectal and axillary temperature measurements in preterm infants who were born less than 32 weeks' gestation using digital thermometers upon their admission to the Neonatal Intensive Care Unit (NICU). Prospective, observational, single centre study. Rectal and axillary temperatures measurements were performed using a digital thermometer. The study examined various maternal and neonatal factors to describe the study group, including the use of prenatal corticosteroids, the occurrence of maternal diabetes and hypertension, a history of maternal prolonged rupture of membranes (PROM), maternal chorioamnionitis, the mode of delivery, along with the neonate's gender, birth weight, and gestational age. The Pearson correlation coefficient (R) was calculated to ascertain the linear relationship between the temperatures taken at the rectal and axillary sites. The concordance between the two sets of temperature data was analyzed using the Bland-Altman method. Eighty infants with a mean gestational age of 28.4 weeks (SD = 2.9) and a mean birth weight of 1,229 g (SD = 456) were included in the study. The mean axillary temperature was 36.4 °C (SD = 0.7), which was lower than the mean rectal temperature of 36.6 °C (SD = 0.6) (p = 0.012). Rectal temperatures surpassed axillary measurements in 59% of instances, while the reverse was observed in 21% of cases. Rectal and axillary temperatures had a strong correlation (Pearson correlation coefficient of 0.915, p < 0.001). Bland-Altman plot showed a small mean difference of 0.1C between the two temperatures measurements but the limits of agreement were wide (+0.7 to -0.6 °C). For hypothermic infants, the mean difference between rectal and axillary temperatures was 0.27 °C, with a wide limit of agreement ranging from -0.5 °C to +1 °C. Conversely, for normothermic infants, the mean difference was smaller at 0.1 °C, with a narrower limit of agreement from -0.4 °C to +0.6 °C. While there is a good correlation between axillary and rectal temperatures, the wider limits of agreement indicate variability, particularly in hypothermic infants. For a more accurate assessment of core body temperature in hypothermic infants, clinicians should consider using rectal measurements to ensure effective thermal regulation and better clinical outcomes.

Antipyretic activity of the hydro-alcoholic extract of Artemisia absinthium L. as a standalone and as an adjuvant with barley water against yeast-induced pyrexia in albino Wistar rats.

In Unani medicine, a comprehensive treatment plan has been delineated to deal with febrile illnesses using herbal drugs along with modified dietetics, which stands as apromising area of research. The present study was aimed atevaluating the antipyretic activity of the HAE of Artemisia absinthium L. whole plant as a standalone and as an adjuvant with barley water in an animal model of pyrexia tovalidate the age-old Unani principle of the treatment. The pyrexia was induced in all the groups except the plain control using Brewer's yeast. Group II did not receive any treatment, while group III received crocin, group IV received HAE of A.absinthium, group V administered Maal-Sha'ir, and group VI was treated with the HAE of A.absinthium along with Ma al-Sha'ir by oral route. The rectal temperature of each rat was recorded at '0' h, 30 min, 60 min, and 180 min. The mean rectal temperature of group III went down from 101.82±0.20 °F to 100.4±0.57 °F over the period of(0-180) minutes, whereas the mean temperature in groupIV went down from 102.45±0.60 °F to 100.14±0.57 °F. The mean rectal temperature of group V decreased from 100.62±0.11 °F to 99.55±0.51 °F, while the mean rectal temperature of group VI went down from 101.95±0.1 °F to97.7±0.11 °F. It is concluded that the HAE of A.absinthium L. as a standalone and along with Ma al Sha'ir showed excellent antipyretic activity as compared to the standard drug in an animal model.

Correlation and agreement between infrared thermography and a thermometer for equine body temperature measurements.

Body temperature is a vital sign that determines physical status. Infrared thermography (IRT) is more frequently used for assessing horses' temperature because of its ease of use and less contact with the horses, making it a safer measurement method. However, the accuracy of IRT remains unclear; therefore, this study aimed to assess the potential use of IRT as an alternative method for measuring horse body temperature. Temperatures were measured in 14 horses. A digital thermometer was used to collect rectal temperature (RT), whereas a thermographic camera was used for IRT at three different positions to obtain the center of body temperature (CBT), head temperature (HT), and eye temperature (ET). The protocol was performed over 30 days, repeated thrice daily: morning (6:00-8:00), afternoon (14:00-15:00), and evening (17:00-19:00). Environmental factors, including humidity, ambient temperature, wind flow, and light intensity, were recorded indirectly according to the time of day and cooling device use. Mean RT, CBT, HT, and ET were 37.33°C, 34.08°C, 35.02°C, and 35.14°C, respectively. Center of body temperature was lower than RT by an average of 3.24°C (95% confidence interval [CI], 5.4°C-1.09°C). HT was lower than RT by an average of 2.3°C (95% CI, 4.33-0.28). The eye position showed the least difference between RT and infrared temperature, with an average of 2°C (95% CI, 0.7-3.92). However, there was no significant correlation between RT and infrared temperature at any position. Spray and vaporizer use significantly affected IRT and time of day (p = 0.05). Although IRT has advantages in terms of non-invasiveness and reduced stress on horses, its accuracy and reliability may be compromised by environmental variables, which interfere with infrared measurement. Future research should specifically focus on investigating environmental factors.

PSXIII-6 Effects of High Humidity Under High-Temperature Conditions on Growing Pigs

Abstract Global warming and climate change have become major concerns. These changes have led to more frequent and prolonged heat waves, resulting in economic losses for livestock industry. Pigs are particularly vulnerable to heat stress under high temperatures due to their thick skin layers and limited sweat glands. Panting is a common behavior in pigs to dissipate heat through evaporation, but this process is less effective in high humidity environments. This study was conducted to investigate the effects of high humidity under high temperature conditions on rectal temperature, growth performance, blood profiles, and immune responses of growing pigs. A total of 48 growing pigs [(Landrace × Yorkshire) × Duroc; initial body weight (BW): 23.21 ± 3.77 kg] were randomly assigned to two environmental treatments (2 pigs/pen; 12 replicates/treatment) in a randomized complete block design (block = initial BW): thermal neutral conditions (TN: 23.5℃, 35%) and heat stress conditions (HS: 32.5℃, 80%). Throughout two weeks of experiment, the pigs had ad libitum access to a basal grower diet based on corn and soybean meal. The rectal temperature of each pig was measured daily throughout the experimental period to monitor changes in body temperature. Blood samples were collected from 1 pig per pen at the beginning and end of the experiment. Measurements included growth performance [BW, average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio], blood profiles [the number of white blood cells (WBC), red blood cells, hemoglobin, hematocrit, and platelet] measured by an automated hematology analyzer calibrated for porcine blood, and immune responses (cortisol, tumor necrosis factor-alpha, interleukin-6, interleukin-1beta, and transforming growth factor-beta1) by the ELISA kits. Statistical analysis was performed using the general linear model procedure of the SAS program. Experimental unit was a pen. The statistical model included environmental treatment as a main effect and BW as a covariate for rectal temperature, growth performance, blood profiles, and immune responses. During the entire experimental period, the mean rectal temperature was 39.9℃ for TN and 40.5℃ for HS. Pigs under HS had decreased (P &amp;lt; 0.05) ADG and ADFI than those under TN. The WBC counts of pigs under HS were decreased (P &amp;lt; 0.05) than those under TN. In contrast, serum cortisol concentrations of pigs under HS were greater (P &amp;lt; 0.05) than those under TN. In conclusion, this study suggests that exposure to high humidity in combination with high temperatures has a negative impact on the growth performance and immune responses of growing pigs.

Arterial oxygenation and acid-base status before and during oxygen supplementation in captive European bison (Bison bonasus) immobilized with etorphine-acepromazine-xylazine.

Chemical immobilization of captive European bison (Bison bonasus) is often required for veterinary care, transportation, or husbandry practices playing an important role in conservation breeding and reintroduction of the species. We evaluated the efficiency and physiological effects of an etorphine-acepromazine-xylazine combination with supplemental oxygen in 39 captive European bison. Animals were darted with a combination of 1.4 mg of etorphine, 4.5 mg of acepromazine, and 20 mg of xylazine per 100 kg based on estimated body mass. Arterial blood was sampled on average 20 min after recumbency and again 19 min later and analyzed immediately with a portable i-STAT analyzer. Simultaneously, heart rate, respiratory rate, and rectal temperature were recorded. Intranasal oxygen was started after the first sampling at a flow rate of 10 mL.kg-1.min-1 of estimated body mass until the end of the procedure. The initial mean partial pressure of oxygen (PaO2) was 49.7 mmHg with 32 out of 35 sampled bison presenting with hypoxemia. We observed decreased respiratory rates and pH and mild hypercapnia consistent with a mild respiratory acidosis. After oxygen supplementation hypoxemia was resolved in 21 out of 32 bison, but respiratory acidosis was accentuated. Bison immobilized with a lower initial drug dose required supplementary injections during the procedure. We observed that lower mean rectal temperatures during the immobilization event were significantly associated with longer recovery times. For three bison, minor regurgitation was documented. No mortality or morbidity related to the immobilizations were reported for at least 2 months following the procedure. Based on our findings, we recommend a dose of 0.015 mg.kg-1 etorphine, 0.049 mg.kg-1 acepromazine, and 0.22 mg.kg-1 xylazine. This dose reduced the need for supplemental injections to obtain a sufficient level of immobilization for routine management and husbandry procedures in captive European bison. Nevertheless, this drug combination is associated with development of marked hypoxemia, mild respiratory acidosis, and a small risk of regurgitation. Oxygen supplementation is strongly recommended when using this protocol.

Whole genome transcriptomic reveals heat stroke molecular signatures in humans.

An evolutionary heat shock response (HSR) protects most living species, including humans, from heat-induced macromolecular damage. However, its role in the pathogenesis of heat stroke is unknown. We examined the whole genome transcriptome in peripheral blood mononuclear cells of a cohort of subjects exposed to the same high environmental heat conditions, who developed heat stroke (n=19) versus those who did not (n=19). Patients with heat stroke had a mean rectal temperature at admission of 41.7 ±0.8°C, and eight were in deep coma (Glasgow Coma Score=3). The transcriptome showed that genes involved in more than half of the entire chaperome were differentially expressed relative to heat stress control. These include the heat shock protein, cochaperone, and chaperonin genes, indicating a robust HSR. Differentially expressed genes also encoded proteins related to unfolded protein response, DNA repair, energy metabolism, oxidative stress, and immunity. The analysis predicted perturbations of the proteome network and energy production. Cooling therapy attenuated these alterations without complete restoration of homeostasis. We validated the significantly expressed genes by a real-time polymerase chain reaction. The findings reveal the molecular signature of heat stroke. They also suggested that a powerful HSR may not be sufficient to protect against heat injury. The overwhelming proteotoxicity and energy failure could play a pathogenic role. KEY POINTS: Most living species, including humans, have inherent heat stress response (HSR) that shields them against heat-induced macromolecular damage. The role of the HSR in subjects exposed to environmental heat who progressed to heat stroke versus those that did not is unknown. Our findings suggest that heat stroke induces a broad and robust HSR of nearly half of the total heat shock proteins, cochaperones, and chaperonin genes. Heat stroke patients exhibited inhibition of genes involved in energy production, including oxidative phosphorylation and ATP production. Significant enrichment of neurodegenerative pathways, including amyloid processing signalling, the Huntington's and Parkinson's disease signalling suggestive of brain proteotoxicity was noted. The data suggests that more than a powerful HSR may be required to protect against heat stroke. Overwhelming proteotoxicity and energy failure might contribute to its pathogenesis.

Body temperatures, thermal comfort, and neuropsychological responses to air temperatures ranging between 12°C and 39°C in people with Multiple Sclerosis

The negative effects of thermal stress on Multiple Sclerosis (MS)’ symptoms have long been known. However, the underlying mechanisms of MS heat and cold intolerance remain unclear. The aim of this study was to evaluate body temperatures, thermal comfort, and neuropsychological responses to air temperatures between 12 and 39 °C in people with MS compared to healthy controls (CTR). Twelve MS (5 males/7 females; age: 48.3 ± 10.8 years; EDSS range: 1–7) and 11 CTR participants (4 males /7 females; age: 47.5 ± 11.3 years) underwent two 50-min trials in a climatic chamber. Air temperature was ramped from 24 °C to either 39 °C (HEAT) or 12 °C (COLD) and we continuously monitored participants’ mean skin (Tsk) and rectal temperatures (Trec), heart rate and mean arterial pressure. We recorded participants’ self-reported thermal sensation and comfort, mental and physical fatigue, and we assessed their cognitive performance (information processing). Changes in mean Tsk and Trec did not differ between MS and CTR neither during HEAT nor COLD. However, at the end of the HEAT trial, 83% of MS participants and 36% of CTR participants reported being “uncomfortable”. Furthermore, self-reports of mental and physical fatigue increased significantly in MS but not CTR (p < 0.05), during both HEAT and COLD. Information processing was lower in MS vs. CTR (p < 0.05); yet this cognitive impairment was not exacerbated by HEAT nor COLD (p > 0.05). Our findings indicate that neuropsychological factors (i.e. discomfort and fatigue) could contribute to MS heat and cold intolerance in the absence of deficits in the control of body temperature.

Comparative evaluation of the efficacy of different marbofloxacin-based products in pigs at the nursery, growth and finish phases with clinical signs of respiratory disease

Marbofloxacin is one of the antibiotics of choice for the treatment of pigs with clinical manifestations of respiratory disease. Some commercial products on the market contain this active ingredient, and the objective of this study was to evaluate the efficacy of 3 available marbofloxacin-based products based on the SISAAB (single injection and short-term antibiotic) concept with regard to the performance and health parameters of pigs in the nursery, growth and termination phases with clinical manifestations of respiratory disease (RD). A total of 78 animals with clinical manifestations of RD from a total of 1726 pigs were used. The animals that had RD symptoms were weighed, identified and randomly subjected to 3 treatments: T1 - Forcyl® (n = 27); T2 - Marbox® (n = 25); T3 - Resolutor® (n = 26). All treatments corresponded to a single intramuscular dose of 8 mg of marbofloxacin per kg of live weight. After treatment, clinical signs of cough and depression, water consumption, rectal temperature, performance parameters, lung lesions and the pneumonia index of the animals were evaluated. The animals that received T1 and T3 maintained a mean rectal temperature of 39.38 °C 2 days after administration. In contrast, animals in the group that received T2 had significantly higher temperatures (p = 0.068) in this period (39.53 °C). There was a greater decrease in temperature (p = 0.042) in the 24 hours after drug administration in animals that received T1 (-0.573 °C). Regarding the other performance parameters, clinical signs of cough and depression, water consumption, lung injury and the pneumonia index, no differences were observed between the marbofloxacin-based products evaluated (p &gt; 0.05). All marbofloxacin-based products were effective in reducing the clinical signs of RD and promoting animal performance and health. However, T1 was more effective in reducing the rectal temperature of the animals.

Clinical and Antinociceptive Effects of Distal Inferior Alveolar Nerve Block in Ponies With Tramadol 5% or Lidocaine 2.

This study aimed to compare the antinociceptive effects of tramadol 5% and lidocaine 2% on mental nerve block in horses of the Brazilian Pony breed. Eight adult non-pregnant mares were used in this study. The ponies were tranquilized with acepromazine (5 µg kg-1, IV), and the infiltration of the mental foramen was performed in Treatment 1- tramadol 5% (T, 150 mg) or Treatment 2- lidocaine 2% (L, 60 mg), both at a total dose of 3 ml in each foramen. Heart rate (HR), respiratory rate (RR), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP), rectal temperature (RT), and formation of skin lesions (SL) were evaluated. Evaluation of nociception of the outer lip (OL), inner lip (IL), and gingiva (GG) were performed using an electronic von Frey device with the evaluation of the ponies' reactions to each stimulus. From these reactions, we determined latency time (LT) and duration of antinociception (DAN). Analysis of variance with 16 observations was performed for HR, RR, SAP, DAP, MAP, LT and DAN. Data were expressed as mean ± standard deviation and the means were compared by the SNK and Student's t-test (P< 0.05). Changes in HR, RR, SAP, DAP, and MAP between evaluation times were associated with the effects of acepromazine (P>0.05). No formation of skin lesions was observed. Latency time did not differ between treatments (P>0.05). Both lidocaine 2% and tramadol 5% produced an antinociceptive effect. We conclude that the duration of the antinociceptive effect of tramadol 5% is longer than that of lidocaine 2%.

Effects of packing (load carrying) on body temperatures and their circadian rhythms in donkeys (Equus asinus) during the hot-dry season

The study aimed to evaluate the effects of packing (load carrying) on rectal and body surface temperatures and their circadian rhythmicity in donkeys during the hot-dry season. Twenty pack donkeys of both sexes (15 males and 5 non-pregnant females), aged 2–3 years, with average weight of 93 ± 2.7 kg and divided into two groups randomly, served as experimental subjects. Group 1 donkeys (packing + trekking) were subjected to packing in addition to trekking, while group 2 (trekking only) did not carry any load. All the donkeys were trekked, covering a distance of 20 km. The procedure was repeated three times within the week, one day apart. During the experiment, dry-bulb temperature (DBT), relative humidity (RH) and temperature-humidity index (THI), wind speed and topsoil temperature were recorded; and rectal temperature (RT) and body surface temperature (BST) were measured before and immediately after packing. Starting from 16 h after the last packing, circadian rhythms of RT and BST were recorded at 3-h intervals for 27-h period. The RT and BST were measured by digital thermometer and non-contact infrared thermometer, respectively. The DBT and RH, especially after packing (35.83 ± 0.2 °C and 20.00 ± 0.0%, respectively), were outside the thermoneutral zone for donkeys. The RT value (38.63 ± 0.1 °C) in packing + trekking donkeys recorded immediately (15 min) after packing was higher (P < 0.05) than the value obtained in trekking only donkeys (37.27 ± 0.1 °C). The overall mean RT recorded during the continuous 27-h period of measurement, starting from 16 h after the last packing procedure was higher (P < 0.05) in packing + trekking donkeys (36.93 ± 0.2 °C) compared with trekking only donkeys (36.29 ± 0.3 °C). The BSTs recorded in both groups were higher (P < 0.05) immediately after packing when compared with pre-packing values, but insignificant 16-h post-packing. The RT and BST values were generally higher in the photophase and lower during the scotophase in both groups of donkeys during the continuous recordings. The eye temperature was the closest to the RT, followed by scapular temperature, while the coronary band temperature was the farthest. The mesor of RT in packing + trekking donkeys (37.06 ± 0.2 °C) was significantly higher than in donkeys that were trekked only (36.46 ± 0.1 °C). The amplitude of RT in trekking only donkeys (1.20 ± 0.1 °C) was wider (P < 0.05) than that obtained in packing + trekking donkeys (0.80 ± 0.1 °C). The acrophase and bathyphase occurred later in packing + trekking donkeys (18:10 ± 0.3 h and 6:10 ± 0.3 h, respectively), compared to the trekking only donkeys (16:50 ± 0.2 h and 4:50 ± 0.2 h, respectively). In conclusion, exposure to thermally stressful prevailing environmental conditions during packing increased the body temperature responses, especially in packing + trekking donkeys. Packing significantly influenced the circadian rhythms of body temperatures in working donkeys, as evidenced by differences in circadian rhythm parameters in packing + trekking group, compared with trekking only donkeys during the hot-dry season.

Dairy Cow Thermal Balance Model During Heat Stress: Part 2. Model Assessment

Highlights The thermal balance model body temperature and respiration rate results compared well with published data. Model results were commonly within one standard deviation of reported averages. Research that measures more model inputs, coefficients, and results is needed. The thermal balance model can be used to identify heat stress factors and assess mitigation practices. Abstract. A steady-state process-based lactating cow thermal balance spreadsheet model developed by Nelson and Janni (in press) was compared to mean measured body temperatures, respiration rates, and skin temperatures from two published studies (Gebremedhin et al., 2010; Chen et al., 2015). Model body temperatures were also compared with reticular temperatures from cows standing in unshaded paddocks that were part of a solar shade study (Sharpe et al., 2021). Gebremedhin et al. (2010) reported measured mean rectal temperatures, 39.4 ± 0.5 C and 40.6 ± 0.4 C for hot and dry conditions with and without a solar load; model body temperatures for similar hot and dry conditions were 39.7 C and 40.6 C with and without a solar load, respectively. Model respiration rates were within one standard deviation of measured mean respiration rates (Gebremedhin et al., 2010). The model body temperature for a baseline condition was 39.1°C, which was within 0.1°C of the mean baseline temperature of 39.2 ± 0.6°C (Chen et al., 2015). The model respiration rate was 63 breaths per minute (bpm); much lower than the reported baseline respiration rate of 88 bpm (Chen et al., 2015). Model body temperatures were 0.1°C to 0.7°C lower than the measured mean reticular temperatures of standing cows in non-shaded paddocks with solar loads when ambient temperatures ranged from 24.4°C to 26.5°C. Model results compared well with mean measured parameters from three studies. The model can be used to assess the impact of factors affecting heat exchange (e.g., body mass, milk yield, solar load, air dry-bulb temperature, dew-point temperature, and air velocity) on heat exchange flux, cow respiration rate, and body temperature. Keywords: Body temperature, Dairy, Heat stress, Lactating cow, Respiration rate, Thermal balance model.

Effects of maternal choline supplementation on performance and immunity of progeny from birth to weaning.

The objectives were to investigate whether supplementation with rumen-protected choline (RPC) during late pregnancy in Holstein cows affects offspring immunity and growth, and whether effects are utero-placental, colostrum dependent, or both. A total of 105 multiparous Holstein cows were assigned randomly to a prepartum diet (1.54 Mcal of NEL/kg of DM, and 15.8% CP) without (control) or with added RPC (12.9 g/d of choline ion). Calves (n = 111) were blocked by sex and assigned randomly to colostrum from control cows or colostrum from RPC cows, resulting in 4 treatments in a 2 × 2 factorial arrangement: (1) calves born and fed colostrum from non-supplemented dams (NN; n = 33); (2) calves from non-supplemented dams and fed colostrum from RPC-fed cows (NC; n = 25); (3) calves from RPC-supplemented dams and colostrum from non-supplemented cows (CN; n = 28); and (4) calves from RPC-supplemented dams and colostrum from RPC-fed cows (CC; n = 25). Growth, intakes, and immunity of females were evaluated up to 56 d of age. Growth and intake of male calves was evaluated up to 35 d of age, and physiological and immune responses to intravenous LPS challenge were evaluated from 21 to 35 d of age. Effects of prenatal and colostrum treatments and interactions between treatments were analyzed using mixed models. Calves fed colostrum from RPC-supplemented dams had a 17.4% increase in apparent efficiency of absorption of IgG compared with calves fed colostrum from control dams (27.4 vs. 23.3%). Incidence of fever in the first 21 d of age tended to be less in females born from RPC-supplemented dams compared with females born from control dams (31 vs. 58%). Prenatal RPC females had increased hematocrit and concentrations of red blood cells, leukocytes, neutrophils, and lymphocytes in blood compared with prenatal females born from control dams. Compared with prenatal control females, prenatal RPC females had greater intake of milk replacer (704 vs. 748 ± 9.9 g/d) and starter (45.4 vs. 60.2 ± 5.9 g/d) during the first 21 d of age. In male calves, mean intake of DM was greater (1,074 vs. 976 ± 45 g/d) after the LPS challenge (0 to 8 d) by calves born from dams fed RPC compared with males born from control dams. Calves born from RPC-fed dams also had lower mean rectal temperature (39.0 vs. 39.2°C) and mean respiration rate (35.6 vs. 39.3 breaths/min) compared with males born from control dams. Moreover, serum concentrations of metabolites (i.e., β-hydroxybutyric acid, fatty acids, and glucose), cytokines (i.e., tumor necrosis factor-α) and acute phase proteins (i.e., serum amyloid A) were consistent with less-severe inflammatory response to LPS in males born from dams fed RPC compared with control. Source of colostrum and interaction between prenatal and colostrum treatments had minimal effects on calf responses to LPS. Overall, maternal RPC supplementation during late gestation suggests a positive effect on immunity, in that colostrum from RPC-fed dams increased efficiency of IgG absorption and maternal supplementation with RPC during late gestation, regardless of colostrum source, attenuated responses to LPS.

Is Selective Head Cooling Combined with Whole-Body Cooling the Most Effective Hypothermia Method for Neonatal Hypoxic-Ischemic Encephalopathy?

This study aimed to compare combined hypothermia (CH) to the 2 classical therapeutic hypothermia (TH) methods selective head cooling (SHC) and whole-body cooling (WBC). This retrospective cohort study included neonates who underwent CH, SHC, and WBC between 2012 and 2020. Mean rectal temperature was maintained at 33.5 ± 0.5°C by cooling the head and the body in the CH group, at 34.5 ± 0.5°C by cooling the head in the SHC group, and at 33.5 ± 0.5°C by cooling the body in the WBC group. The groups were compared in terms of side effects, magnetic resonance imaging (MRI) scores, and status at discharge. The study included 60 neonates in the CH group, 112 in the WBC group, and 27 in the SHC group. There was no significant difference in side effects between the groups (p > 0.05). There was no significant difference in brain MRI scores between the groups (p > 0.05); however, gray matter, white matter, and total MRI scores in the CH group were lower than in the WBC group. Duration of hospitalization was shorter in the CH group than in the other two groups (p = 0.022). CH was not associated with more side effects than the two classical TH methods. In addition, some of these findings suggest that CH might result in better clinical outcome than the two classical TH methods.