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Heat stress is a significant problem for poultry health and performance. Approaches to mitigate heat stress in poultry include epigenetic programming by early life exposure to stimulations such as high temperatures and food restriction. In a songbird species (zebra finch) that is adapted to living in hot desert climates, exposure of embryos to adult vocalisations ("heat calls") improves heat tolerance in offspring. Domestic poultry auditory systems also detect and encode sounds during late embryonic development, making it possible that prenatal exposure to specific sounds could be used to efficiently and safely engineer more heat resistant poultry. Ross 308 broiler chicken embryos were exposed to simulated heat call (SHC, n = 30) or control (CON, n = 30) sounds in separate incubators for 5 days, starting from embryonic day 17 until hatch. Sounds were played at ~85 dB for 5 minutes every 15 minutes, for 12 hours per day. SHC sounds were shorter, higher frequency sounds with energy concentrated in a few frequency bands that were rapidly repeated whereas CON sounds were longer, lower frequency sounds with energy spread out across frequency bands and with longer and variable intervals between sounds. Sound duration, frequency range, and repetition rates were within range of chicken vocalisations. Embryonic heart rate before and during sound playback was measured daily using a non-invasive digital monitor (Buddy Egg Mk2). Incubation temperature and relative humidity of both treatment groups was 37.61°C and 61.7%. At hatch, hatching success, chick quality (Tona score), body weight, and rectal temperature were measured. Body weight and rectal temperature were measured again at postnatal day 7. Rectal temperature at postnatal day 7, but not at hatch, was statistically significantly elevated in SHC chicks compared to CON chicks (mean ± SEM SHC = 41.04 ± 0.053°C; CON = 40.86 ± 0.051°C). This effect was likely caused by our treatment altering physiological arousal because heart rate of SHC embryos decreased significantly during sound exposure (mean ± SEM before = 241 ± 3.10 bpm; during = 231 ± 3.33 bpm), whereas heart rate of CON embryos did not (mean ± SEM before = 239 ± 2.85 bpm; during = 233 ± 3.06 bpm). Hatching success, chick quality, and body weight were not affected by our prenatal sound treatment. Conclusions: Our data showing increased rectal temperature suggest that rapid, rhythmic, and frequency-modulated high-pitched sounds during incubation could potentially alter thermal tolerance and preference in domestic chickens. [ABSTRACT FROM AUTHOR]

Recently, we showed that oral administration of crystallized L-citrulline (L-Cit) caused hypothermia under a control thermoneutral temperature (CT) and provided thermotolerance under high ambient temperature (HT) in chicks. The aim of this study was to clarify whether oral administration of a medium containing L-Cit-producing live bacteria can reduce body temperature in chicks under CT. In Experiment 1, 7-day-old chicks were orally administered either a medium (containing mainly L-Cit-producing live bacteria and 277 mM L-Cit) or an equimolar amount of L-Cit to determine their effects on body temperature (acute treatment). In Experiment 2, chicks were subjected to the same treatment from 7 to 13 days of age (chronic treatment). Rectal and surface body temperatures were recorded daily after 1 h of treatment. Both acute and chronic oral administration of the medium, but not of the equimolar amount of L-Cit, significantly reduced the rectal and surface body temperatures of the chicks. Chronic administration of the medium resulted in consistently low rectal and surface body temperatures during the entire experimental period. In conclusion, acute or chronic administration of the medium containing L-Cit-producing live bacteria, but not of the equimolar amount of L-Cit, reduced the rectal and surface body temperatures of the chicks. Our results suggest that medium containing L-Cit-producing live bacteria can be used as a new feed supplement for lowering the body temperature of chicks.

Damage to the spinal cord results in malfunction of sympathetic pathways, which consequently influences thermoregulation during exercise. A consensus view is that athletes with spinal cord injury (SCI) are at a heightened thermal strain than the able-bodied athletes. However, a number of studies have reported similar increases in core body temperature in both populations. This study presented an up-to-date review of core body temperature response to exercise, from a meta-analytic point of view. Inclusion criteria were persons with SCI and control population (either healthy persons or wheelchair athletes without SCI) completed an exercise trial and their core body temperature responses were recorded under the same environmental conditions. Effect of SCI on thermoregulatory capabilities was quantified as raw mean core body temperature difference. Twelve studies examining 100 persons with SCI (Cervical (C2) to Lumbar (L5)) and 97 persons without SCI were meta-analyzed. The exercise interventions were submaximal exercise and the unweighted means ± standard deviations heat index and exercise duration were 31.5±11.9°C and 57±20 min, respectively. Regardless of injury, core body temperature was not different: raw mean difference, 0.048°C; 95% confidence interval, -0.12°C to 0.22°C. In conclusion, under SCI sport-specific exercise and environmental conditions, SCI does not produce outsized thermoregulatory impact, though the influence could be variable as a result of different lesion levels.

This study was conducted to investigate the behaviour, selected physiological indicators and body mass changes in Nigerian indigenous broody hens. The times spent by the hens sitting on eggs and on ingestive behaviours (feeding and drinking) were monitored between 14:00 and 18:00 h twice per week for three weeks. The growth and physiological indicators monitored were body mass, rectal temperature, breast temperature and blood glucose concentration. Data collected were analysed using repeated measures ANOVA of SPSS having week as the repeated factor. The time spent by hens sitting on the eggs (88.09 ± 5.38 – 92.91 ± 2.35 %) and on ingestive behaviours (0.06 ± 0.03 – 0.11 ± 0.07 %) were similar at the 1st, 2nd and 3rd week of brooding. The blood glucose concentration was reduced at the 1st and 2nd but increased at the 3rd week while the breast temperature (BT) increased at the 1st and 2nd but dropped at the 3rd week. The rectal temperature and body mass did not differ significantly (P > 0.05) during the three weeks of the brooding process. In conclusion, natural brooding of embryos by hens under tropical conditions was accompanied by changes in body metabolism required for generation of heat which is transferred through the breast region of the hens to the eggs without necessarily resulting in higher rectal temperature of the hens.

Objective Heat stress poses an increasing threat for poultry production. Some amino acids have been found to play critical roles in affording thermotolerance. Recently, it was found that in ovo administration of L-leucine (L-Leu) altered amino acid metabolism and afforded thermotolerance in heat-exposed broiler chicks. Methods In this study, two doses (35 and 70 μmol/egg) of L-Leu were administered in ovo on embryonic day 7 to determine their effect on rectal temperature (RT), body weight (BW) and thyroid hormones at hatching. Changes in RT, BW, and thermotolerance in post-hatched chicks were also analyzed. Results It was found that in ovo administration of L-Leu dose-dependently reduced RT and plasma thyroxine (T4) level just after hatching. In post-hatched neonatal broiler chicks, however, the higher dose of L-Leu administered in ovo significantly increased RT without affecting BW gain. In chicks that had been exposed to heat stress, the RT was significantly lowered by in ovo administration of L-Leu (high dose) in comparison with the control chicks under the same high ambient temperature (HT: 35°C±1°C, 120 min). Conclusion In ovo administration of L-Leu in a high dose contributed to an increased daily body temperature and afforded thermotolerance under HT in neonatal broiler chicks.

The aim of the present study was to investigate the response to physical exercise of some ocular physiological variables (ocular temperature and intraocular pressure) in horses performing a jumping course in the morning (a.m.) or in the afternoon hours (p.m.), before and after the exercise, in correlation with the rectal temperature. Data collection was carried out on 14 clinical healthy Italian saddle horses. All horses were trained from 9:00 to 10:00 a.m. and from 19:00 to 20:00 p.m. according to a specific training program. Ocular temperature (OT), rectal temperature (RT) and intraocular pressure (IOP) were determined. Statistical analysis showed no differences between the results for the left and the right eyes. The application of two-way repeated-measures analysis of variance (ANOVA) showed a statistically significant effect of time (before vs. after) on IOP (p = 0.0001). RT and OT were statistically influenced by time of day and by experimental conditions (a.m. vs. p.m.) (p = 0.0001). Bland–Altman (B-A) testing showed an agreement between the values of RT and OT. Our results showed a correlation between increased body temperatures and IOP variations during exercise, so they can probably be considered indicators of athletic horses’ physical fitness during exercise.

Abstract Background A new generation of ear thermometers with preheated tips and several measurements points should allow a more precise temperature measurement. The aim of the study was to evaluate if the ear temperature measured by this ear thermometer can be used to screen for fever and whether the thermometer is in agreement with the rectal temperature and if age, use of hearing devices or time after admission influences the temperature measurements. Methods Open cross-sectional clinical single site study patients, > 18 years old, who were acutely admitted to the short stay unit at the ED. A sample size of 99 patient per subgroup was recruited as random convenience series. As ear thermometer Braun Thermoscan Pro 4000® and as rectal thermometer Omron Flex Temp Smart ® was used. For different cut off of temperature the AUC was calculated and Bland-Altman analysis for calculation of 95% limits of agreement with rectal temperature, with subgroup analysis concerning age, time span from admission time and use of hearing aid. Results Among 599 patients the sensitivity to detect fever with an ear thermometer varied between 68 and 70% with AUC from 0.88–0.97. If the ear temperature was ≥37.5 oC, the sensitivity to detect patients with ≥38.0 oC rectally was 95% which raised to 100% for a rectal temperature of ≥38.3 oC. For the ear thermometer’s ability to determine the exact temperature the 95% limits of agreement were +/− 0.8 oC. with no influence from age, duration of hospital stay or hearing aids. Conclusion The examined ear thermometer is able to detect fever, defined as ≥38 oC rectally in an adult ED population by using an ear cut-point of 37.5 oC, but not to measure the exact temperature. Used in this way around a fifth of the patients will still be in need of a rectal temperature measurement, but less than 5% with fever ≥38.0 oC will remain undetected and none with fever ≥38.3 oC. Age, admission time and use of hearing aid did not influence the temperature measurements. Trial registration Clinical Trials: ID NCT02977481, date 11/18/2016.

Clinical Scenario: Many American football players have died from exertional heatstroke, one of the leading causes of sudden death in athletes. These athletes are predisposed to exertional heatstroke, in part, because of their protective equipment. Few authors have systematically appraised the research to determine how much faster rectal temperature (Trec) increases when full American football uniforms generally consisting of a helmet, shoulder pads, jersey, pants with padding, socks, shoes, and underwear/compressions (PADS) are worn compared with no uniform so that clinicians can better plan and modify exercise sessions to prevent dangerous Trec (i.e., ≥40.5 °C). Clinical Question: How much faster does Trec increase when men wear a full American football uniform compared with workout clothing during exercise in the heat? Summary of Key Findings: The authors searched the literature for randomized controlled studies with PEDro scores >6 that compared Trec of males wearing PADS to a control uniform during exercise under controlled laboratory conditions. In all four studies, Trec increased faster when PADS were worn during exercise (PADS = 0.052 ± 0.007 °C/min and control = 0.039 ± 0.009 °C/min). The average effect size across studies was 1.4 ± 0.5. Clinical Bottom Line: PADS increase Trec significantly faster than lesser uniform ensembles. Clinicians should factor in equipment and alterations in exercise duration and rest break frequency to help prevent dangerous Trec in American football players. Strength of Recommendation: Given the large effect size and controlled experimental study designs, there is strong evidence that wearing PADS during exercise results in faster increases in body core temperature. [ABSTRACT FROM AUTHOR]

Genetic selection for improved climatic resilience is paramount to increase the long-term sustainability of high-producing dairy cattle, especially in face of climate change. Various physiological indicators, such as rectal temperature (RT), respiration rate score (RR), and drooling score (DS), can be used to genetically identify animals with more effective coping mechanisms in response to heat stress events. In this study, we investigated genetic parameters for RT, RR (score from 1–3), and DS (score from 1–3). Furthermore, we assessed the genetic relationship among these indicators and other economically important traits for the dairy cattle industry. After data editing, 59,265 (RT), 30,290 (RR), and 30,421 (DS) records from 13,592 lactating Holstein cows were used for the analyses. Variance components were estimated based on a multiple-trait repeatability animal model. The heritability ± standard error estimate for RT, RR, and DS was 0.06 ± 0.01, 0.04 ± 0.01, and 0.02 ± 0.01, respectively, whereas their repeatability was 0.19, 0.14, and 0.14, respectively. Moderate genetic correlations of RR with RT and DS (0.26 ± 0.11 and 0.25 ± 0.16) and nonsignificant correlation between RT and DS (−0.11 ± 0.14) were observed. Furthermore, the approximate genetic correlations between RT, RR, and DS with 12 production, 29 conformation, 5 fertility and reproduction, 5 health, and 9 longevity-indicator traits were assessed. In general, the approximate genetic correlations calculated were low to moderate. In summary, 3 physiological indicators of heat stress response were measured in a large number of animals and shown to be lowly heritable. There is a value in developing a selection index including all the 3 indicators to improve heat tolerance in dairy cattle. All the unfavorable genetic relationships observed between heat tolerance and other economically important traits can be accounted for in a selection index to enable improved climatic resilience while also maintaining or increasing productivity in Holstein cattle. [ABSTRACT FROM AUTHOR]

Context: Cold-water immersion (CWI) may not be feasible in some remote settings, prompting the identification of alternative cooling methods as adjunct treatment modalities for exertional heat stroke (EHS). Objective: To determine the differences in cooling capacities between CWI and the inhalation of cooled air. Design: Randomized controlled clinical trial. Setting: Laboratory. Patients or Other Participants: A total of 12 recreationally active participants (7 men, 5 women; age = 26 6 4 years, height = 170.6 6 10.1 cm, mass = 76.0 6 18.0 kg, body fat = 18.5% 6 9.7%, peak oxygen uptake = 42.7 6 8.9 mLkg-1 min-1 ). Intervention(s): After exercise in a hot environment (408C and 40% relative humidity), participants were randomized to 3 cooling conditions: cooling during passive rest (PASS; control), CWI, and the Polar Breeze thermal rehabilitation machine (PB) with which participants inspired cooled air (22.28C 6 1.08C). Main Outcome Measure(s): Rectal temperature (TREC) and heart rate were continuously measured throughout cooling until TREC reached 38.258C. Results: Cooling rates during CWI (0.188Cmin-1 6 0.068Cmin-1 ) were greater than those during PASS (mean difference [95% CI] of 0.168Cmin-1 [0.138Cmin--1, 0.198Cmin-1 ]; P, .001) and PB (0.158Cmin-1 [0.128Cmin-1 , 0.168Cmin-1 ]; P, .001). Elapsed time to reach a TREC of 38.258C was also faster with CWI (9.71 6 3.30 minutes) than PASS (58.1 minutes [77.1, 39.9 minutes]; P, .001) and PB (46.8 minutes [65.5, 28.2 minutes]; P, .001). Differences in cooling rates and time to reach a TREC of 38.258C between PASS and PB were not different (P . .05). Conclusions: Transpulmonary cooling via cooled-air inhalation did not promote an optimal cooling rate (.0.158Cmin-1 ) for the successful treatment of EHS. In remote settings where EHS is a risk, access and use of treatment methods via CWI or cold-water dousing are imperative to ensuring survival. [ABSTRACT FROM AUTHOR]

Objective: First, we will update recommendations for the prehospital management and care of patients with exertional heat stroke (EHS) in the secondary school setting. Second, we provide action items to aid clinicians in developing best-practice documents and policies for EHS. Third, we supply practical strategies clinicians can use to implement best practice for EHS in the secondary school setting. Data Sources: An interdisciplinary working group of scientists, physicians, and athletic trainers evaluated the current literature regarding the prehospital care of EHS patients in secondary schools and developed this narrative review. When published research was nonexistent, expert opinion and experience guided the development of recommendations for implementing life-saving strategies. The group evaluated and further refined the action-oriented recommendations using the Delphi method. Conclusions: Exertional heat stroke continues to be a leading cause of sudden death in young athletes and the physically active. This may be partly due to the numerous barriers and misconceptions about the best practice for diagnosing and treating patients with EHS. Exertional heat stroke is survivable if it is recognized early and appropriate measures are taken before patients are transported to hospitals for advanced medical care. Specifically, best practice for EHS evaluation and treatment includes early recognition of athletes with potential EHS, a rectal temperature measurement to confirm EHS, and cold-water immersion before transport to a hospital. With planning, communication, and persistence, clinicians can adopt these best-practice recommendations to aid in the recognition and treatment of patients with EHS in the secondary school setting. [ABSTRACT FROM AUTHOR]

The use of protective clothing under extreme conditions leads to heat stress with undesired consequences on human physiology. As a prevention measure, thermal indices and thermophysiological models have been developed. Based on these models and indices, it is possible to estimate the time limits for staying under risky conditions, e.g., by the predicted rectal temperature whose value is one of the most important parameters used for assessing the heat stress. This article is focused on the comparison of rectal and mean skin temperature prediction realized by the Fiala-based thermophysiological model (FMTK) and Predicted heat strain (PHS) index with results from the real experiment for normal and protective clothing. Three types of ensembles were tested and simulated as follows: Klimatex underwear, air-permeable military NBC suit M2000 (FOP), and impermeable chemical protective clothing Tychem-F. The real experiments of thermal strain were performed with one male participant (80 kg, 1.75 m) walking on the treadmill located in the climate chamber. The temperature range for neutral and hot tests was set from 25 °C to 40 °C. The rectal temperature, skin temperatures, and heart rate were measured. The results showed that PHS index is well usable for normal clothing (Klimatex underwear) and air-permeable protective clothing (FOP) under various ambient temperatures, and it is able to give results similar to FMTK model and experiment, the mean absolute error MAE for rectal temperature prediction was for all ambient temperatures lower than 0.5 °C. FMTK model demonstrated good predictability for impermeable protective clothing Tychem-F, the maximum value of MAE 0.69 °C. Whereas PHS index showed several times larger error, the maximum value higher than 1.8 °C, in the prediction for this type of clothing. The performed simulations showed that the accuracy of the prediction by the PHS index is not so strongly dependent on the value of the overall clothing resistance, but it depends on the value of the moisture permeability index (permeable vs impermeable clothing) which is connected with the water vapor partial pressure under the clothing. [ABSTRACT FROM AUTHOR]

The installation of fans and rooftop sprinklers in swine housing and management facilities can increase noise intensity and may impair workers' hearing health over longs periods of time; therefore, an assessment of the piglets’ stress during invasive practices was made. This study set out to evaluate the noise intensity emitted by environmental enrichment devices (fans and rooftop sprinklers) and by piglets restrained for body temperature assessments and its effect on animal welfare and on the hearing health of workers exposed to it for long periods. Twenty piglets ranging in age from five to twenty days were observed. The sow gestation area was divided into a cooled (fans and rooftop sprinklers) and uncooled area. Two decibel meters were used to measure noise intensity, one for the general noise in the facilities and the other for the piglets, with five-minute intervals between assessments. Digital thermometers were used to take the rectal temperature, and infrared thermometers were used to take the body surface temperature. Fixed-effects ANOVA for the housing environment and periods and multiple comparisons at a significance level of 5% were applied. The average dorsal temperature of the piglets was 36 °C ± 1.2 in the cooled area and 38.4 °C ± 0.5 in the uncooled area. In both periods, the average maximum noise intensity was over 100 decibels. In the afternoon, the maximum intensity was higher for the uncooled environment. The results indicate that neither the fans nor the rooftop sprinklers installed in the facilities nor the squealing piglets during restraint affect the noise intensity of the environment. However, the noise intensity demonstrates the piglets’ stress and the need for protective equipment to preserve the workers’ hearing health.

Piglets are poor at thermoregulation immediately following birth and take up to 24 h to recover from their initial temperature drop. The present study aimed to determine if providing piglets with a 15 mL intraperitoneal injection of warm (45 °C) saline at birth would improve their internal temperature recovery to 24 h of age, and how the treatment interacted with birth weight (BWC = 1; ≤0.80 kg, BWC = 2; 0.81 kg to 1.10 kg, and BWC = 3; >1.10 kg), rectal temperature at 1.5 h (RC = 1; ≤32.0 °C, RC = 2; 32.10 °C to 35.0 °C, and RC = 3; ≥35.10 °C), and colostrum intake (CI = 1; p < 0.001) and BWC3-RC3 piglets (p < 0.001). Treated BWC1 improved survival to 20 d (p < 0.001). Irrespective of BWC, piglets from all RC had greater survival when injected with saline. The greatest difference was for piglets in RC1, likely due to all BWC1 piglets falling within this category. The results suggest that an intraperitoneal injection of warmed saline is an effective way to improve piglet temperature recovery to 24 h, colostrum intake, and survival in low-birth-weight piglets. These findings will be helpful for producers who have large numbers of low-birth-weight piglets born and are able to provide individual care.

Hypothermia is directly linked to metabolism; however, it is still unknown how the overall metabolism is altered by oral administration of hypothermic agent, L-citrulline (L-Cit). The present study aimed to determine the characteristics of liver metabolites of chicks orally administered L-Cit to provide a greater understanding of its metabolism. Capillary electrophoresis-time-of-flight mass spectrometry (CE-TOFMS) and liquid chromatography-time-of-flight mass spectrometry (LC-TOFMS) were conducted on liver samples after oral administration of L-Cit. A total of 361 liver metabolites were identified. Although a small number of samples were used for each group, a principal component analysis and heatmap patterns confirmed that the composition of metabolites could be segregated from each other. Of the 361 compounds detected in the liver, 41 compounds, including amino acids related to the Cit-arginine (Arg) cycle, argininosuccinic acid, Arg, ornithine, and Cit, as well as gamma aminobutyric acid, glycine, histidine, and nicotinamide adenine dinucleotide were abundant in L-Cit-treated livers. In contrast, 24 compounds containing fatty acids, amino acids, and cyclic adenosine monophosphate were lower in the L-Cit group. These data imply that the active Cit-Arg cycle, TCA cycle metabolism, and a low activity in fatty acid metabolism occur in L-Cit-treated broiler chicks. [ABSTRACT FROM AUTHOR]

We examined the effects of oral administration of L-citrulline (L-Cit) on plasma metabolic hormones and biochemical profile in broilers. Food intake, water intake, and body temperature were also analyzed. After dual oral administration (20 mmol/head/administration) of L-Cit, broilers were exposed to a high ambient temperature (HT; 30 ± 1°C) chamber for 120 min. Oral administration of L-Cit reduced (p < .001) rectal temperature in broilers. Food intake was increased (p < .05) by heat stress, but it was reduced (p < .05) by L-Cit. Plasma levels of 3,5,30-triiodothyronine, which initially increased (p < .0001) due to heat stress, were reduced (p < .01) by oral administration of L-Cit. Plasma insulin levels were increased by heat exposure (p < .01) and oral L-Cit (p < .05). Heat stress caused a decline (p < .05) in plasma thyroxine. Plasma lactic acid (p < .05) and non-esterified fatty acids (p < .01) were increased in L-Cit-treated heat-exposed broilers. In conclusion, our results suggest that oral L-Cit can modulate plasma concentrations of major metabolic hormones and reduces food intake in broilers. [ABSTRACT FROM AUTHOR]

The evaluation was performed with 25 cows from dairy 17, belonging to Dos Ríos enterprise, in order to assess the relation between the temperature and humidity index, rectal temperature and respiratory rate. The information was taken at three times of the day: morning, midday and afternoon. The results showed that in the morning the cows are in a thermo neutral zone (temperature and humidity index 69.59), while at midday they are under medium heat stress (THI 79.61), and in the afternoon under severe stress (THI 91.69). Under severe heat stress, the rectal temperature of pregnant lactating cows increased (P = 0.0136) by 0.28 ºC with respect to the rectal temperature of non-pregnant lactating cows. The respiratory rate was not affected by the light temperature and humidity index. But in the moderate stress, pregnant cows showed higher (P = 0.0003) respiratory rates of 1.9 and 2.0 % in relation to non-pregnant cows for moderate and severe stress, respectively. The physiological response to the temperature and humidity index, according to the milking group, showed that the high production group had higher rectal temperature values (P = 0.0003) in 0.16 and 0.21 oC and the respiratory rate increased (P = 0.0024) in 9.21 and 7.89 % in relation to the average group, for moderate and severe stress, respectively. Under the conditions of this study, at midday and afternoon, the animals are under moderate and severe stress, respectively, conditions that affect more the lactating pregnant animals and the open cows or the highest production group. [ABSTRACT FROM AUTHOR]

Background: Exposure to a high ambient temperature (HT) can cause heat stress, which has a negative impact on physiological functions. L-tryptophan (L-Trp) as a precursor of serotonergic and kynurenine (Kyn) pathways, has a calmative effect during different stress statuses. Aims: This study was carried out to determine the influence of intraperitoneal injection of Trp on feeding behavior, rectal temperature, and some blood parameters in the heat stress condition. Methods: L-tryptophan (25 and 50 mg/kg body weight, BW) was administered intraperitoneally during either HT (39°C) or control temperature (CT; 31°C) for 5 h whilst fed or fasted in 7-day-old chicks. Results: L-tryptophan caused elevation in decreased food intake and significantly decreased rectal temperature during acute heat stress at the dose of 50 mg/kg BW. Rectal temperature reduced in the fasted state at the dose of 50 mg/kg BW, and at the dose of 25 mg/kg BW Trp in the fed state in comparison with the other experimental groups. Reduction of serum glucose, triglyceride, and corticosterone levels was seen during the fed state. L-tryptophan had a significant reducing effect on the serum corticosterone level in the fasted state in comparison with the fed state, and also revealed a significant decline at the dose of 25 mg/kg BW on the elevated serum corticosterone under heat stress. Conclusion: Administration of L-tryptophan leads to increase cumulative food intake and decrease rectal temperature during heat stress. Also, L-Trp causes to decline increased serum corticosterone level under heat stress and fasted state. These findings indicated the potential regulator role of Trp to modulate stress response in heat-exposed chicks. [ABSTRACT FROM AUTHOR]

The aim of the research was to study the effect of heat stress (HS) on some physiological and productive traits in Holstein-Friesian dairy cows. The study included 22 cows on different parities. In the building where the cows were housed, the temperature-humidity index (THI) was reported at 10:00 and 15:00 h, at the same time the rectal temperature (RT) and respiratory rate (RR) were reported for each of the examined cows. The daily rumen activity was taken from the SCR system by Allflex. The average THI values in May were 71, in June - 75, in July - 74, and in August - 77, from which it follows that in the summer months the cows were in conditions of mild to moderate heat stress throughout the day. The average daily milk yield of the cows increased from May to June and reached 41.44 kg day-1, then decreased in July and August to 37.2 and 32.48 kg day-1, respectively. With an increase in the THI values, an increase in the RR and RT was registered, as in THI above 79 the RR was 56.54 per min, and the RT was 39.33 °C. With increasing the THI values, the rumination of the cows decreased from 563 per day at THI < 72 to 542.5 at THI > 79. In cows with high daily milk yield, a higher RT was registered, and in cows with more than 50 kg per day, the RT was 39.09 °C. A more intense rumination was found in cows with higher daily milk yield. In cows with an average daily milk yield of 33.26 kg, an average of 450 ruminations per day were reported, and in those with an average milk yield of up to 42.89 kg - 650 ruminations per day. From the research conducted it was found that the studied physiological traits - rectal temperature, respiration rate and rumination are influenced by HS and the intensity of this effect depend on the daily milk yield of cows and THI levels. [ABSTRACT FROM AUTHOR]

Two early feathering sire lines (B1 and B2), two late feathering dam lines (A1 and A3), and an early feathering dam line were evaluated to determine differences in growth, in lengths of primary feathers, in under-wing and rectal temperatures, and in feed intake until the birds were 20 weeks old. The chicks were hatched from eggs collected from 35-week-old hens of pure line broiler flocks. Data were collected at hatch, and at 1, 2, 4, 6, 8, 12, and 20 weeks old Thirty males and 30 females were evaluated for each line. The early feathering genotypes (A2, B1 and B2) had longer primary feathers until they were six weeks old. They also had higher under-wing and rectal temperatures and higher live weight compared with the late-feathering lines (A1 and A3) at one and two weeks old. The males were heavier than females at all ages. However, under-wing and rectal temperatures were similar in males and females at all ages. A positive correlation was observed between the length of primary feathers and live weight in A2, B1, and B2 at six weeks, whereas a negative correlation was observed between the rectal temperature and the length of primary feathers in A1 and A3 at 4 and 20 weeks old. [ABSTRACT FROM AUTHOR]

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Infrared thermography of the lateral side portion of the udder was taken from 38 lactating cows in a 6-day experiment. Thermograms were analyzed using specific software with the use of eight different methods. The experiment was aimed at correlating the different methods with each other and with rectal temperature (RT), in order to suggest a method to assess udder side temperature, and also at creating regression equations to enable RT calculation through the use of thermographic data. All methods of analyzing thermograms were highly correlated; correlations between thermograms and RT were significant (P < 0.01) and above 0.840. The highest correlation was between RT and the maximum temperature obtained using a horizontal rectangle placed within the lateral (side) portion of the udder (maximum temperature in a horizontal rectangle (MHR), 0.897). With the exception of the average temperature of a horizontal rectangle, linear regression coefficients were significant (P < 0.05) and coefficients of determination were higher than 75.51%. We suggest the use of MHR to evaluate udder side temperature. The ease of accessing the side of the udder, the welfare advantages of non-invasive observations, and the high correlation with RT suggest the use of thermograms in the lateral portion of the udder to assess animals’ temperature. [ABSTRACT FROM AUTHOR]

Context: Little information exists regarding what exertional heatstroke (EHS) survivors know and believe about EHS best practices. Understanding this would help clinicians focus educational efforts to ensure survival and safe return-to-play following EHS., Objective: We sought to better understand what EHS survivors knew about EHS seriousness (e.g., lethality, short- and long-term effects), diagnosis and treatment procedures, and recovery. Design: Multi-year, cross-sectional, descriptive design., Setting: An 11.3-km road race located in the Northeastern United States in August 2022 and 2023., Patients or Other Participants: Forty-two of 62 runners with EHS (15 women, 27 men; age: 33±15 y; pre-treatment rectal temperature [TREC]: 41.5±0.9°C)., Interventions: Medical professionals evaluated runners requiring medical attention at the finish line. If they observed TREC ≥40°C with concomitant central nervous system dysfunction (CNS) EHS was diagnosed and patients were immersed in a 189.3-L tub filled with ice-water. Before medical discharge, we asked EHS survivors 15 questions about their experience and knowledge of select EHS best practices. Survey items were piloted and validated by experts and laypersons a priori (content validity index ≥0.88 for items and scale)., Main Outcome Measures: Survey responses., Results: Sixty-seven percent (28/42) of patients identified EHS as potentially fatal and 76% (32/42) indicated it negatively affected health. Seventy-nine percent (33/42) correctly identified TREC as the best temperature site to diagnose EHS. Most patients (74%, 31/42) anticipated returning to normal exercise within 1 week post-EHS; 69% (29/42) stated EHS would not impact future race participation. Patients (69%, 29/42) indicated it was important to tell their primary care physician about their EHS., Conclusions: Our patients were knowledgeable on the potential seriousness and adverse health effects of EHS and the necessity of TREC for diagnosis. However, educational efforts should be directed towards helping patients understand safe recovery and return-to-play timelines following EHS.

Heat stress is an environmental factor that negatively affects the morphological and physiological properties of dairy cattle. The aim of this study is to investigate the relationship between heat stress and milk yield, milk fat ratio and body temperature in Holstein-Friesian dairy cattle. The data of the study was obtained from a private Kurtalan Farm of Siirt province, the Southeastern Anatolia Region of Turkey. Milk yield and other traits of 13 head Holstein- Friesian dairy cattle were recorded in March, April, May, June, July, August and September. In addition, temperature and humidity records were recorded in the farm and in the parlor to be used for calculating the temperature humidity index value. In the analysis of data, correlation and regression methods were used. As a result of the study, the negative correlation (P<0.01) was found between milk yield and milk fat ratio and the positive correlation (P<0.001) were detected between heat stress and body temperature. In addition, a significant negative relationship was observed between rectal temperature and milk yield (P<0.01). [ABSTRACT FROM AUTHOR]

Because dogs tolerate conventional rectal temperature measurements poorly, a calibrated infrared thermometer was tested for assessing canine body surface temperature. Body surface temperature of 204 dogs was estimated on various sites (digit, snout, axilla, eye, gum, inguinal region, and anal verge). Having rectal temperature as the gold standard, temperature difference, Spearman's correlation coefficient, hyperthermia and hypothermia detection sensitivity and specificity, and stress response score was calculated for each measurement site. Although the canine body surface temperature was considerably lower than the rectal temperature, there was a moderate correlation between both temperatures. Spearman's coefficients were 0.60 (p < 0.001) for the inguinal region with a single operator and 0.50 (p < 0.001) for the gum with multiple operators. Measurement site on the gum additionally guaranteed hyperthermia detection sensitivity and specificity up to 90.0% (95% CI: [66.7 100]) and 78.6% (95% CI: [71.6 85.2]), respectively. Measurements with the infrared thermometer provoked a statistically significant lower stress response (mean stress scores between 1.89 and 2.48/5) compared to the contact rectal measurements (stress score of 3.06/5). To conclude, the correct body surface temperature measurement should include a calibrated thermometer, reliable sampling, and the control of external factors such as ambient temperature influence. The transformation of body surface temperature to the recognized rectal temperature interval allows more straightforward data interpretation. The gum temperature exhibited the best clinical potential since the differences to rectal temperatures were below 1°C, and hyperthermia was detected with the sensitivity of up to 90%.

Heat acclimation (HA) is an essential modifier of physiological strain when working or exercising in the heat. It is unknown whether HA influences the increase of energy expenditure (Q10 effect) or heart rate (thermal cardiac reactivity TCR) due to increased body temperature. Therefore, we studied these effects using a heat strain database of climatic chamber experiments performed by five semi-nude young males in either non-acclimated or acclimated state. Measured oxygen consumption rate (VO2), heart rate (HR), and rectal temperature (Tre) averaged over the third hour of exposure were obtained from 273 trials in total. While workload (walking 4 km/h on level) was constant, heat stress conditions varied widely with air temperature 25–55°C, vapor pressure 0.5–5.3 kPa, and air velocity 0.3–2 m/s. HA was induced by repeated heat exposures over a minimum of 3 weeks. Non-acclimated experiments took place in wintertime with a maximum of two exposures per week. The influence of Tre and HA on VO2 and HR was analyzed separately with mixed model ANCOVA. Rising Tre significantly (p < 0.01) increased both VO2 (by about 7% per degree increase of Tre) and HR (by 39–41 bpm per degree Tre); neither slope nor intercept depended significantly on HA (p > 0.4). The effects of Tre in this study agree with former outcomes for VO2 (7%/°C increase corresponding to Q10 = 2) and for HR (TCR of 33 bpm/°C in ISO 9886). Our results indicate that both relations are independent of HA with implications for heat stress assessment at workplaces and for modeling heat balance.

The objective of the present study was to compare the effects of propofol and ketofol on intraocular pressure, tear production and cardiorespiratory variables in dogs premedicated with midazolam. Six castrated adult mixed-breed dogs were used in a cross-over design with a one-week interval. Twenty minutes after premedication with midazolam (0.2 mg/kg), animals were assigned randomly to two groups and received either propofol (6 mg/kg) or ketofol (3 mg/kg; 1 : 1 mg/ml ratio) treatments intravenously. Intraocular pressure, tear production, heart rate, respiratory rate, rectal temperature and direct mean arterial blood pressure were measured at base (before induction), and at 5, 10, 15, 20 and 30 min after induction of anaesthesia. Blood gas samples were obtained at base (before induction), and at 5, 15 and 30 min after administration of treatments. Intraocular pressure showed significantly higher values at 5 min after induction in ketofol compared with propofol (16.1 ± 4.5 mm Hg vs 8.2 ± 1.2 mm Hg, respectively). There were no significant changes in tear production in either group. Significantly higher heart rate and mean arterial blood pressure were detected in ketofol at several time points. Respiratory depression occurred in both groups with no significant differences between them. In conclusion, although ketofol improved heart rate and mean arterial blood pressure and did not elicit more pronounced respiratory depression than propofol, it resulted in significantly higher values of intraocular pressure at 5 min after administration in dogs. Despite the small number of dogs in this study, our results indicate that ketofol should not be recommended for ophthalmic surgical procedures in dogs. Appropriate oxygenation should be provided when propofol is used for ophthalmic surgeries.

Dog sports competitions have greatly expanded. The availability of reference values for each type of activity could help assess fitness accurately. Heart rate (HR), blood lactate (BL) and rectal temperature (RT) are relevant physiological parameters to determine the dogs response to effort. Previous studies in greyhounds have reported the effect of high-intensity exercise on many physiological parameters immediately after completing different racing distances and recovery times. However, there are no studies concerning physiological changes over shorter racing distances. We therefore assessed the effect of sprint exercise on HR, BL and RT in nine greyhounds performing sprint exercise over a 100-m distance chasing a lure. After the exercise, dogs underwent a passive 10-min recovery phase. Before the exercise, immediately after it and at 5 and 10 min during recovery, HR and RT were assessed and blood samples were collected for BL determination. HR, BL and RT values increased significantly after the exercise (P0.1), BL concentration and RT remained increased (P

Abstract Background Measuring rectal temperature in children is the gold standard, but ear or forehead measures are less traumatic and faster. The quality of non-invasive devices has improved but concerns remain whether they are reliable enough to substitute rectal thermometers. The aim was to evaluate in a real-life children population whether the forehead or ear temperature measurements could be used in screening to detect fever and if the agreement with the rectal temperature for different age groups is acceptable for clinical use. Methods Cross-sectional clinical study comparing temporal and tympanic temperatures to rectal temperature in 0–18-year-old children. The ear thermometer was a Pro 4000 Thermoscan, the temporal Exergen TAT. Rectal temperature ≥ 38.0 °C was defined as fever. Results Among 995 children, 39% had a fever. The ear thermometer had a significantly greater ability to detect fever than the temporal thermometer (AUC 0.972; 95% CI: 0.963–0.981 versus AUC 0.931; 95% CI: 0.915–0.947, p

Context: Australia exports ~2 million sheep annually. On these voyages, sheep can be exposed to rapidly changing ambient conditions within a short time, and sheep may be exposed to periods of excessive heat load. Aims: The aim of this study was to define the responses of sheep exposed to incremental heat load under simulated live export conditions. The study herein describes the influence of heat load on wool surface temperature, body temperature (rumen temperature (TRUM), °C; and rectal temperature (TREC), °C) and respiratory dynamics (respiration rate, breaths/min; and panting score (PS)) of sheep under live export conditions. In addition, the relationship between body temperature and respiratory dynamics was investigated. Methods: A total of 144 Merino weathers (44.02 ± 0.32 kg) were used in a 29-day climate controlled study using two cohorts of 72 sheep (n = 2), exposed to two treatments: (1) thermoneutral (TN; ambient temperature was maintained between 18°C and 20°C), and (2) hot (HOT; ambient temperature minimum and maximum were 22.5°C and 38.5°C respectively). Sheep in the HOT treatment were exposed to heat load simulated from live export voyages from Australia to the Middle East. Respiration rate, PS and wool surface temperature (°C) data were collected four times daily, at 3-h intervals between 0800 hours and 1700 hours. Rectal temperatures were collected on five occasions at 7-day intervals. These data were evaluated using a repeated measures model, assuming a compound symmetry covariance structure. Individual TRUM were obtained via rumen boluses at 10-min intervals between Days 23 and 29 of Cohort 2. Individual TRUM data were collated and converted to an hourly mean TRUM for each sheep, these data were then used to determine the hourly mean TRUM for TN and HOT, then analysed using a first order autoregressive repeated measures model. Additionally, the relationship between respiratory dynamics and TRUM were investigated using a Pearson's correlation coefficient, a partial correlation coefficient and a multivariate analysis of variance. Key results: The respiration rate of the HOT sheep (140 ± 3.55 breaths/min) was greater (P < 0.01) than that of the TN sheep (75 ± 3.55 breaths/min). Similarly, the PS of the HOT (1.5 ± 0.02) sheep was greater (P = 0.009) compared with the TN sheep (1.2 ± 0.02). Wool surface temperatures and TREC were greater (P < 0.05) for the HOT sheep than for the TN sheep. There were treatment (P < 0.0001), hour (P < 0.0001), day (P = 0.038) and treatment × hour (P < 0.0001) effects on the TRUM of TN and HOT sheep. Conclusions: The climatic conditions imposed within the HOT treatment were sufficient to disrupt the thermal equilibrium of these sheep, resulting in increased respiration rate, PS, TREC and TRUM. Implications: These results suggest that the sheep were unable to completely compensate for the imposed heat load via respiration, thus resulting in an increase in TREC and TRUM. During live export voyages, sheep can be exposed to relatively rapid changes in ambient conditions within a short period of time (≤29 days), raising heat load concerns. This study highlighted that the climatic conditions imposed were sufficient to disrupt the thermal equilibrium of these sheep, resulting in increased respiration rate, panting score and body temperature. Overall, these results suggest that the sheep were unable to completely compensate for the imposed heat load via increased evaporative heat loss through respiration, resulting in an increase in body temperature. [ABSTRACT FROM AUTHOR]

The present study was designed with an objective to evaluate the impact of various strategies to alleviate heat stress on certain physiological attributes viz. respiratory rate (RT), body surface temperature (BST), pulse rate (PR), and respiratory rate (RR); biochemical attributes viz. glucose, total protein (TP), and cholesterol; and endocrinological parameters (tri-iodothyronine and tetraiodothyronine) of the Nili-Ravi buffaloes during early summer season. Lactating Nili-Ravi buffaloes (n = 20) with close production and parity stage were divided into four treatment groups as group A (control group under roof shades only), B (experimental group under roof shades with antistress supplementation), C (experimental group under roof shades with ceiling fans), and D (experimental group under showers and ceiling fans) at the Buffalo Research Institute, Punjab, Pakistan. All the physiological study parameters, that is, RT, BST, PR, and RR, were significantly (P ≤ 0.05) higher for Group A and B as compared to Group C and D, respectively. The results revealed that all the biochemical study attributes were significantly (P ≤ 0.05) higher in Group C and D as compared to Group A and B. Regarding endocrinological parameters (T3 and T4), both these hormones were significantly (P ≤ 0.05) different between the four study groups, being higher for Group D as compared to the other groups. Nili-Ravi buffaloes showed a resistant behavior in terms of RR, PR, and serum biochemical components, which implies that the fan strategy could be an alternative to showering. [ABSTRACT FROM AUTHOR]

This study aimed to determine the effects of replacing corn with hydroponically sprouted barley (HSB) in Holstein heifer feed on growth performance and blood metabolites. For this purpose, the barley was prepared with hydroponic sprouting under optimized conditions, and its chemical composition was analyzed on a dry matter (DM) basis. A total of 30 Holstein heifers that were 7 months old with an average body weight of 212.60 ± 55.00 kg were used in a completely randomized design comprising 10 repetitions and three groups over a period of 11 months. Dietary treatments included control (CON), basal diet (corn meal-based diets), and trail diets, in which 10% and 30% HSB gradually replaced corn meal. The growth performance and biochemical indices were analyzed every month. Results showed that the HSB diet increased chemical compositions compared with the control diets on a DM basis. In addition, diets with up to 30% HSB did not show any negative effects on the growth performance (body weight, height at withers, and height at rump) or selected blood metabolites of heifers compared with the CON diet. In conclusion, the use of HSB instead of corn meal did not lead to any adverse effects on growth performance or biochemical indices; therefore, HSB can be used as an alternative dietary source for raising Holstein heifers. [ABSTRACT FROM AUTHOR]

The aim of this study was to gain insights in respect to how locally adapted goats exhibit dynamic body heat in an equatorial semi-arid environment. Ten Canindé goats were used in the study (22.90 ± 2.70 kg). Respiratory rate (RR; min breaths−1), rectal temperature (RT; °C) and sweating rate (SR; g m−2 h−1) were measured for 8 days, once a week, for 8 consecutive weeks in each animal, with collection intervals of 1 h throughout the day (24 h), together with the meteorological variables. Air temperature (AT, °C) and relative humidity (RH, %) were measured, and then, the temperature humidity index (THI) was calculated. First, we determined 2 days with stressful climatic conditions and similar environmental characteristics (day 1 and 2) among the 8 experimental days. The RT was evaluated on these 2 days using the means of each hour as the cut-off point, and determining whether the animals are efficient (EF) or inefficient (INEF) in heat loss (β1) and gain (β2). The RT was separated in β1 and β2 for 24 h, setting times to obtain the angular coefficients (β) for both. The days with stressful climatic conditions and similar environmental characteristics were day 1 and 2. The hours in which the Canindé goats gained and lost heat were respectively 11 a.m. to 3 p.m. and from 4 p.m. to 10 a.m. The animals classified as EF lost more or equal the amount of heat represented for RT. When the mean of all animals was evaluated for efficiency in heat control, the flock was classified as EF. Differences (P < 0.05) were observed for RR and SR between periods. The efficiency in dynamic body heat of the locally adapted goats in this study was determined and showed that the flock as a whole possesses an excellent heat dynamic in an equatorial semi-arid environment. [ABSTRACT FROM AUTHOR]

The installation of fans and rooftop sprinklers in swine housing and management facilities can increase noise intensity and may impair workers' hearing health over longs periods of time; therefore, an assessment of the piglets' stress during invasive practices was made. This study set out to evaluate the noise intensity emitted by environmental enrichment devices (fans and rooftop sprinklers) and by piglets restrained for body temperature assessments and its effect on animal welfare and on the hearing health of workers exposed to it for long periods. Twenty piglets ranging in age from five to twenty days were observed. The sow gestation area was divided into a cooled (fans and rooftop sprinklers) and uncooled area. Two decibel meters were used to measure noise intensity, one for the general noise in the facilities and the other for the piglets, with five-minute intervals between assessments. Digital thermometers were used to take the rectal temperature, and infrared thermometers were used to take the body surface temperature. Fixed-effects ANOVA for the housing environment and periods and multiple comparisons at a significance level of 5% were applied. The average dorsal temperature of the piglets was 36 °C ± 1.2 in the cooled area and 38.4 °C ± 0.5 in the uncooled area. In both periods, the average maximum noise intensity was over 100 decibels. In the afternoon, the maximum intensity was higher for the uncooled environment. The results indicate that neither the fans nor the rooftop sprinklers installed in the facilities nor the squealing piglets during restraint affect the noise intensity of the environment. However, the noise intensity demonstrates the piglets' stress and the need for protective equipment to preserve the workers' hearing health. [ABSTRACT FROM AUTHOR]

Exogenous melatonin supplementation may enhance endurance performance because of its pre-cooling effect. The present study aimed to evaluate the effect of acute melatonin ingestion on rectal temperature (Tre) response to submaximal exercise performed in moderate temperature. Eight students moderately trained aged between 20–23 years completed two experimental sessions in a randomized order. The subjects ran on a treadmill for 45 minutes at 60% of their maximal aerobic speed (MAS) after either melatonin-(6mg) or placebo ingestion. Tre, heart rate (HR), thermal sensation (TS) and rating of perceived exertion (RPE) were measured. Blood samples were taken before and after exercise to measure the hemoglobin (Hb), hematocrit (Hct), sodium (Na+) and potassium (K+) concentrations. Melatonin decreased resting Tre by ≈ 0.2°C, but it did not attenuate the increase in core temperature during exercise. At the end of the exercise, HR was significantly attenuated in melatonin condition compared with placebo condition. High dose of melatonin (>5 mg) is not recommended to attenuate the increase of core temperature during continuous exercise. [ABSTRACT FROM AUTHOR]

A basal heat stress test (HST) to predict the magnitude of adaptive responses during heat acclimatization (HA) would be highly useful for the armed forces. The aim was to identify physiological markers assessed during a HST (three 8-min running sets at 50% of the speed at VO2max) performed just before a 14-day HA period that would identify participants still at "risk" at the end of HA. Individuals that responded poorly (large increases in rectal temperature [Trec] and heart rate [HR]) during the initial HST were more likely to respond favorably to HA (large reductions in Trec and HR). However, they were also more likely to exhibit lower tolerance to HST at D15. Basal Trec was found to efficiently discriminate participants showing a Trec > 38.5°C after HA, who are considered to be "at risk". Finally, participants were classified by quartiles based on basal Trec and HR at the end of the HST and physiological strain index (PSI). Most of the participants "at risk" were among the upper quartile (i.e. the least tolerant) of Trec and PSI (p = 0.011 for both). Overall, these results show that the individuals who are less tolerant to a basal HST are very likely to benefit the most from HA but they also remain less tolerant to heat at the end of HA than those who better tolerated the basal HST. A basal HST could therefore theoretically help the command to select the most-ready personnel in hot conditions while retaining those who are less tolerant 6. [ABSTRACT FROM AUTHOR]

Tunnel ventilation is an increasingly popular approach to mitigate the effects of heat stress on dairy cattle. Tunnel-ventilation barns use a bank of high-power fans to move air horizontally from one end of the barn to the other at cow level. The overall objective of the present experiments was to determine whether tunnel ventilation is superior to housing with fans and sprinklers with respect to rectal temperature during heat stress and seasonal variation in milk yield. In the first study, rectal temperatures were measured for 1097 lactating Holstein cows in six freestall barns with fans and sprinklers and 575 lactating Holsteins in four tunnel-ventilated freestall barns at a time point between 14:00 and 16:00 h during the months of June to August in Florida, USA. Rectal temperatures were lower for cows in tunnel-ventilation barns than sprinkler-and-fan barns when the tunnel-ventilation barns were built de novo but not when the tunnel-ventilation barns were produced by retrofitting a sprinkler-and-fan barn (interaction, P = 0.0129). In the second study, average daily milk yield in the first 90 days in milk was examined for 8470 lactating Holsteins housed in three sprinkler-and-fan barns and two tunnel-ventilation barns. Milk production for cows calving in cool weather (October to March) was greater (P < 0.0001) than for cows calving in hot weather (April to September). The seasonal reduction in milk yield was less for cows (P = 0.037) in tunnel-ventilation barns (3.5% decrease) than for cows in sprinkler-and-fan barns (5.8% decrease). With this difference in impact of heat stress, it was estimated at a dairy farm could invest up to a $332 more per cow space in a tunnel-ventilated barn than in a sprinkler-and-fan barn. It was concluded that housing cows in tunnel-ventilation barns can reduce the impact of heat stress on body temperature regulation and milk yield. [ABSTRACT FROM AUTHOR]

The climate-related problems that affect animal production in tropical countries have encouraged seeking solutions to increase herd productivity and one alternative is the use of breeds adapted to high-temperature environments. The objective of this study was to evaluate the effect of temperature on 77 Caracu and Nelore males submitted to three different environments: morning period (8:00 to 10:00 AM), afternoon in the sun, and afternoon in a shaded environment (11:00 AM to 1:00 PM). The following physiological parameters were measured in each treatment: heart and respiration rates, rectal and dorsal surface temperatures, and cortisol level. The data were analyzed with the MIXED procedure (SAS) and the model included the fixed effects of treatment (morning, sun, and shade), breed (Nelore and Caracu), month of measurement (December and February), and the interaction between effects. A higher dorsal surface temperature was observed in animals of both breeds in the sun treatment compared with the shade treatment. Caracu animals had a higher dorsal surface temperature than Nelore animals, which probably caused the higher rectal temperature observed in the sun treatment compared with the shade treatment in both breeds over the 2 months of the study. All physiological parameters measured in this study were efficient to detect the thermal stress in both breeds. Despite the variations in rectal temperature observed during the treatments, the animals of the two breeds exhibited no significant changes in heart rate, respiration rate, and cortisol level for the maintenance of thermal homeostasis. In conclusion, both breeds were considered tolerant to sun exposure, demonstrating adaptation of these animals to high-temperature environments, without evidence of harm to its health and welfare. [ABSTRACT FROM AUTHOR]

The effect of the stay of 6-months-old male Wistar rats under the influence of constant lighting on the daily dynamics of some biochemical parameters was studied. Male Wistar albino rats at the age of 6 months were divided into 2 groups. The rats from the Group I were housed under a fixed illumination, L:D 14:10 (±180 lux, respectively; 8:00 AM lights on) (unless mentioned otherwise) in a temperature-controlled environment with ad libitum access to tap water and food (rat chow). Animals of Group II were studied under the same experimental conditions except for the light regime, representing constant light (LL ±180 lux). Both the first and second groups of animals were kept at the specified light regime for 2 weeks. A number of biochemical parameters of blood plasma have a reliable daily rhythm, while for other metabolites of an organism a circadian rhythm is not noted. The appearance of the previously absent rhythm of physiological parameters after the application of constant lighting indicates the role of other pacemakers in the metabolism, in addition to illumination. The conducted research testifies about the unambiguous modulating influence of constant illumination on the structure of diurnal dynamics of studied biochemical parameters and rectal temperature, and about the initiation of desynchronosis by it. [ABSTRACT FROM AUTHOR]

The objective of the study was to determine the influence of distance to water source on health status of non-descript weaners and does. The goats were situated at 0.25, 0.75, 1.25, 1.75, 2.25, 2.75 and 3.25 km from the Pongola river. Body condition score (BCS) declined faster in male weaners than female weaners as the distance to water source increased (P < 0.001). The rate of decline in BCS was similar between does and female weaners as the distance to water source increased (P > 0.05). Rectal temperature (RT) of all goat classes increased with an increase in distance to water source (P < 0.05). Rate of change in RT was higher in female weaners than male weaners and does as the distance to water source increased (P < 0.01). The increase in FAMACHA scores was higher in male weaners than does and female weaners as the distance to water source increased (P < 0.05). Does had the smallest drop in packed cell volume (PCV) than female and male weaners as the distance to water source increased (P > 0.05). All goat classes were severely affected by the distance to water source; however, the effects were more adverse in male weaners than in female weaners and does. Body condition score and PCV declined, whereas RT and FAMACHA increased with an increase in distance travelled by goats to the water source. It can be concluded that both male and female weaners were more susceptible to increasing distance to water source. [ABSTRACT FROM AUTHOR]

Background: While active heat acclimation strategies have been robustly explored, not many studies highlighted passive heat acclimation strategies. Particularly, little evidence demonstrated advantages of utilizing a water-perfused suit as a passive heating strategy. This study aimed to explore heat adaptive changes in physiological and perceptual responses during 10-day heat acclimation training using a water-perfused suit. Methods: Nineteen young males were divided into three experimental groups: exercise condition (N = 6, HAEXE, 1-h exercise at 6 km h−1 followed by 1-h rest in a sitting position), exercise and passive heating condition (N = 6, HAEXE+SUIT, 1-h exercise at 6 km h−1 followed 1-h passive heating in a sitting position), and passive heating condition (N = 7, HASUIT, 2-h passive heating in a sitting position). All heating programs were conducted for 10 consecutive days in a climatic chamber maintained at 33 °C with 60% relative humidity. The passive heating was conducted using a newly developed water-perfused suit with 44 °C water. Results: Greater whole-body sweat rate and alleviated perceptual strain were found in HASUIT and HAEXE+SUIT after 5 and/or 10 days (P < 0.05) but not in the exercise-only condition (HAEXE). Lower rectal temperature and heart rate were found in all conditions after the training (P < 0.05). Heat adaptive changes appeared earlier in HASUIT except for sweat responses. Conclusions: For heat acclimation in hot humid environments, passive and post-exercise heat acclimation training using the suit (water inflow temperature 44 °C) were more effective than the mild exercise (1-h walking at 6 km h−1). This form of passive heating (HASUIT) may be an especially effective strategy for the elderly and the disabled who are not able to exercise in hot environments. [ABSTRACT FROM AUTHOR]

Very few studies are available on the use of infrared tympanic thermometer to estimate the postmortem interval. The purpose is to observe the decrease of the infrared tympanic temperature according to the postmortem interval under standardized conditions and to compare with the gold standard (rectal temperature). One hundred seventeen cadavers are included at the mortuary of the University Hospital of Nancy from 1 June 2015 to 1 June 2016. The infrared tympanic temperature is measured twice in each ear for each cadaver with a control of these measurements and the taking of rectal temperature for the part of them. In our experiments, the reproducibility of the measurements was excellent between both the ears of one body [intra class coefficient correlation [ICC] = 0.952], the right ear and the left ear with a same observer [ICC = 0.853] and the different observers [ICC = 0.830]. The postmortem interval is correlated with the infrared tympanic temperature (rho = − 0.483; p < 0.0001) with an average of 3.79 h ± 2.38 h. A calculation method is developed (postmortem interval = 16.14 − 0.39 × infrared tympanic temperature). Even if the correlation with the gold standard was correct (rho = 0.505), it is not associated with the postmortem interval (p = 0.0702) due to weakness of the sample. Despite early and only time point postmortem measurements, these results are promising and might impact the forensic science community by drawing the attention of researchers to the estimation of the time period since death and by developing a simple and non-invasive method, even for non-medical investigators at the scene. [ABSTRACT FROM AUTHOR]

The aim of the research was to study the effect of heat stress (HS) and associated changes in the rectal temperature and the respiratory rate on long-chain fatty acid (LCHFA) content in the milk of Holstein-Friesian cows. The study included 22 cows on different parities studied in two periods: under thermo-neutral environment conditions (May 2018) and under heat stress (August 2018). The fatty acid content of milk was determined using a chromatograph by the method of Rose- Gottlieb. It was found that HS in dairy cows leads to changes in the content of some LCHFAs (C17:0; C18:0; C18:2 and C18:3) in milk fat. Under conditions of moderate HS (temperature-humidity index over 79), a certain decrease in the content of C17:0 was reported, while in the other three LCHFAs, an increase in their content in milk fat was reported to varying degrees. The strongest effect of HS was reported on the content of C18:0, which was proportional to the levels of HS. With an increasing rectal temperature, an increase in the content of C18:0 was reported, the increase being most substantial at a rectal temperature above 39.5°C. [ABSTRACT FROM AUTHOR]

The purpose of the study is investigation of thermal stability in athletes of cyclic sports and assessment of its influence on physical working capacity under hyperthermia. Material and methods. 15 male athletes of cyclic sports who had the senior degree as minimum were included in the study Middle age 24,2±1,1 years. Work was performed in the climatic camera of the Center of sports medicine and rehabilitation in several stages, on each of which assessment of physical working capacity and a thermal condition of athletes was carried out. Results. In the real work the burdening action of the heating climate on indicators of physical working capacity and a thermal condition of athletes of cyclic sports is shown; the operating ranges of high temperatures are determined. Conclusion. The data obtained by means of the offered technique, confirm importance of definition of individual thresholds of shipping of a thermal state at athletes and the burdening action of a heat on their physical working capacity.

The immediate response of animals to fluctuations in environmental temperature is an alteration in their physiological responses. For those who failed to cope, their production performance is affected greatly. Fat-rumped sheep is phenotypically different from the commonly available sheep breeds of the semi-arid tropical environment in India. For assessment of thermoregulatory rhythmicity under extreme seasonal variations of the semi-arid tropical region, six adult fat-rumped (Dumba) rams were selected. The study was carried out in the year 2016–2017. All the rams were maintained under stall-feeding condition with a fixed dietary regime. Respiration rate (RR), pulse rate (PR), skin temperature (ST) and rectal temperature (RT) were recorded at morning (08:00 h), and afternoon (14:00 h) in summer (May–June), winter (December–January) and spring (March–April) for six times in each season at 7 days interval. Body weight was taken at the start and end of each season under study. The meteorological data were recorded twice daily at 8:00 h and 14:00 h for the entire study period. The study indicated significant (p < 0.05) variation in RR, PR and ST with respect to season. RT and body weight showed no significant variation among seasons. The result indicated fat-rumped sheep altered their thermoregulatory physiological responses as per the change of season to cope with environmental extremes under semi-arid tropical region. [ABSTRACT FROM AUTHOR]

In rodents, an acute-phase protein, α-1-acid-glycoprotein (AGP), was shown to provide a link between inflammation and suppression of feed intake by acting as a leptin receptor agonist. The objective of this study was to determine the effects of AGP on feed intake and rectal temperature in sheep. Ewes were ovariectomized, implanted with a cannula into a lateral ventricle of the brain, and kept indoors in individual pens. Feed intake and rectal temperature were determined for sheep in all experiments. In the first experiment, ewes (n = 4) received 1 of 4 treatments [0 (control), 0.012 (low), 0.06 (medium), or 0.30 (high) mg/kg BW AGP] into the lateral ventricle (ICV). All sheep received all treatments in a Latin square design balanced for carryover effects with 10 d between treatments. In the second experiment, ewes (n = 10) received 1 of 2 treatments (0 and 3 mg/kg BW of AGP) intravenously (IV) in a completely randomized design. In the third experiment, ewes (n = 19) received peripheral treatments (IV) of an antipyretic [0 (control) or 2.2 mg/kg BW flunixin meglumine (FLU)] 30 min before receiving central AGP [0 (control) or 0.3 mg/kg BW of AGP] in a completely randomized design. All data were analyzed using a mixed model analysis of variance and tested for effects of treatment, time, and the interaction of treatment and time. Cumulative 48-h feed intake after administration of treatments was also determined. In the first experiment, there was no effect of ICV treatment (P = 0.37) on feed intake rate or on cumulative feed intake (P = 0.31). There was an effect of ICV treatment (P = 0.002) on rectal temperatures, which were greater (P < 0.05) after the high dose of centrally administered AGP. In the second experiment, there was no effect of AGP administration IV on feed intake rate (P = 0.98), on cumulative feed intake (P = 0.41) or on rectal temperature (P = 0.71). In the third experiment, there was an effect of central AGP treatment (P < 0.0001) and an interaction of central AGP and time (P < 0.0001) on rectal temperature, whereas FLU had no effect (P = 0.93), demonstrating that AGP increased rectal temperatures regardless of antipyretic treatment. These results indicate that central AGP increases rectal temperature in sheep by pathways that do not involve prostaglandins. Further research is needed to determine whether AGP may be an important integrator of energy balance and inflammation. [ABSTRACT FROM AUTHOR]

Literature examining the effects of aerobic exercise training on excess postexercise oxygen consumption (EPOC) is sparse. In this study, 9 male participants (19-32 yr) trained (EX) for 12 wk, and 10 in a control group (CON) maintained normal activity. VO2max, rectal temperature (Tre), epinephrine, norepinephrine, free fatty acids (FFA), insulin, glucose, blood lactate (BLA), and EPOC were measured before (PRE) and after (POST) the intervention. EPOC at PRE was measured for 120 min after 30 min of treadmill running at 70% VO2max. EX completed 2 EPOC trials at POST, i.e., at the same absolute (ABS) and relative (REL) intensity; 1 EPOC test for CON served as both the ABS and REL trial because no significant change in VO2max was noted. During the ABS trial, total EPOC decreased significantly (p < .01) from PRE (39.4 ± 3.6 kcal) to POST (31.7 ± 2.2 kcal). Tre, epinephrine, insulin, glucose, and BLA at end-exercise or during recovery were significantly lower and FFA significantly higher after training. Training did not significantly affect EPOC during the REL trial; however, epinephrine was significantly lower, and norepinephrine and FFA, significantly higher, at endexercise after training. Results indicate that EPOC varies as a function of relative rather than absolute metabolic stress and that training improves the efficiency of metabolic regulation during recovery from exercise. Mechanisms for the decreased magnitude of EPOC in the ABS trial include decreases in BLA, Tre, and perhaps epinephrine-mediated hepatic glucose production and insulin-mediated glucose uptake. [ABSTRACT FROM AUTHOR]