Temperature-humidity Index Research Articles

Effects of Heat Stress on the Laying Performance, Egg Quality, and Physiological Response of Laying Hens.

As high temperature and relative humidity (RH) are the main environmental factors causing heat stress, the temperature-humidity index (THI) serves as an indicator of heat stress in livestock animals. This study aimed to determine the effects of heat stress on the laying performance, physiological responses, egg quality, and blood profile of laying hens by subjecting them to environmental conditions with varying THI levels (68-85) for 28 days. The indicators of laying performance, such as feed intake (-30%) and egg production rate (-11%), significantly decreased in the hens exposed to severe heat stress (33 °C, 66% RH) compared to those exposed to thermoneutral conditions (21 °C, 68% RH). Moreover, severe heat stress reduced the egg yolk color, eggshell thickness and strength, and Haugh units of the eggs produced by the laying hens. Furthermore, a significant increase in serum K+ and a decrease in Na+ levels were observed in the hens subjected to severe heat stress compared with those under thermoneutral conditions. Our results indicate that heat stress alters the physiological responses and metabolism of laying hens, resulting in a lower egg quality and production rate.

Retreat site occupation and short-term movements in an oasis-dwelling frog in relation to temperature-humidity conditions

The roles of temperature and humidity in shaping diurnal retreat site occupation and short-term movements in amphibians in desert environments have scarcely been studied. In this work, we investigated retreats and movements in the painted frog (Discoglossus pictus auritus) that inhabits oases in arid southern Tunisia, by using a composite temperature-humidity index (THI). Our results show non-random occupation of retreat sites with respect to prevailing temperature-humidity conditions. When leaving retreat sites with THI values above or below their preferred levels, painted frogs tended to move to sites with THI levels more similar to their preferred conditions. We also found that large individuals tended to occupy retreat sites offering similar THI levels, while small individuals moved between sites with very different THI levels, a pattern that could be driven by age-dependent experience. However, there was no significant relationship between the distance moved by painted frogs and the magnitude of the change in the THI between occupied sites. In summary, our findings evidence the role of temperature-humidity conditions in shaping the patterns of diurnal retreat site use in an arid zone amphibian. They also underline the usefulness of composite temperature-humidity indices when assessing amphibian-habitat relationships.

Ambient heat exposure and kidney function in patients with chronic kidney disease: a post-hoc analysis of the DAPA-CKD trial

Higher temperatures are associated with higher rates of hospital admissions for nephrolithiasis and acute kidney injury. Occupational heat stress is also a risk factor for kidney dysfunction in resource-poor settings. It is unclear whether ambient heat exposure is associated with loss of kidney function in patients with established chronic kidney disease. We assessed the association between heat index and change in estimated glomerular filtration rate (eGFR) in participants from the DAPA-CKD trial in a post-hoc analysis. DAPA-CKD was a randomised controlled trial of oral dapagliflozin 10 mg once daily or placebo that enrolled participants aged 18 years or older, with or without type 2 diabetes, with a urinary albumin-to-creatinine ratio of 200-5000 mg/g, and an eGFR of 25-75 mL/min per 1·73 m2. In this post-hoc analysis, we explored the association between time-varying daily centre-level heat index (ERA5 dataset) and individual-level change in eGFR in trial participants using linear mixed effect models and case-time series. The DAPA-CKD trial is registered with ClinicalTrials.gov, NCT03036150. Climate and eGFR data were available for 4017 (93·3%) of 4304 participants in 21 countries (mean age: 61·9 years; mean eGFR: 43·3 mL per 1·73 m2; median 28 months follow-up). Across centres, a heat index of more than 30°C occurred on a median of 0·6% of days. In adjusted linear mixed effect models, within each 120-day window, each 30 days' heat index of more than 30°C was associated with a -0·6% (95% CI -0·9% to -0·3%) change in eGFR. Similar estimates were obtained using case-time series. Additional analyses over longer time-windows showed associations consistent with haemodynamic or seasonal variability, or both, but overall estimates corresponded to an additional 3·7 mL per 1·73 m2 (95% CI 0·1 to 7·0) loss of eGFR per year in a patient with an eGFR of 45 mL per 1·73 m2 located in a very hot versus a temperate environment. Higher ambient heat exposure is associated with more rapid eGFR decline in those with established chronic kidney disease. Efforts to mitigate heat exposure should be tested as part of strategies to attenuate chronic kidney disease progression. None.

The Impacts of Heat and Air Pollution on Mortality in the United States

Abstract Extreme heat events stress the body and can result in fatalities, especially for those with underlying health problems. Air pollution is another threat to health and is an important confounder of extreme heat risks. However, previous empirical studies that have addressed the joint health impacts of air pollution and heat rarely considered the endogeneity and spillover effects of air pollution. To fill this research gap, this article investigates the interconnected impacts of extreme heat and fine particulate matter (PM2.5) on all-cause and cause-specific mortality. We correct the endogeneity of PM2.5 by applying the control function approach and explore transboundary externalities of all-source PM2.5 and wildfire-caused PM2.5. We use a county-year balanced panel dataset covering 2992 U.S. counties from 2001 through 2011. Results show that extreme heat and air pollution exacerbate each other and jointly increase mortality. Specifically, a 1-standard-deviation (SD) increase in the heat index results in 0.60% (95% confidence interval: 0.26%–0.97%), 2.14% (1.34%–2.94%), and 0.86% (0.41%–1.34%) more all-cause fatalities, fatalities from respiratory system diseases, and fatalities from circulatory system diseases, respectively. A 1-SD increase in PM2.5 results in 5.75% (3.61%–7.90%), 6.99% (3.01%–11.15%), and 2.93% (0.66%–5.28%) additional fatalities, respectively. Failure to consider the endogeneity of PM2.5 leads to a substantial underestimation of PM2.5 risk. In addition, our instrumental variable strategy offers evidence of spillover effects from PM2.5 and wildfires. Significance Statement This study illustrates how extreme heat events combined with air pollutants threaten health. This article investigates the interconnected impact of extreme heat and air pollution using data from 2992 United States counties over the 2001–11 period. Results indicate that extreme heat and air pollution jointly increase mortality. Results also show that wind-driven pollution from other counties and wildfires increase mortality.

Milk quality of Italian Mediterranean buffalo as affected by temperature-humidity index during late spring and summer

A total of 18 Italian Mediterranean buffalo cows were subjected to fortnightly milk sampling from May to July 2022. Air temperature and relative humidity were monitored throughout the trial. Temperature-humidity index (THI) was calculated and ranged from 69 to 79, so that 3 classes were set to study the effect of different THI on milk quality: THI less than 72 (THI<72), THI ranging from 72 to 76 (THI72-76), and THI over 76 (THI>76). Individual milk samples from buffalo cows were analyzed for milk composition and coagulation traits, fatty acid and amino acid composition, and enzymatic and mineral profiles. The THI>76 class registered higher lactose content and poorer milk clot characteristics in comparison with THI<72. Exposure to a THI over 76 resulted in increased SFA and short-chain fatty acid contents in milk, as well as in the highest atherogenic and thrombogenic index values and the lowest essential amino acid content. Moreover, the lowest values of calcium, copper, and selenium contents were found in the milk of buffalo cows exposed to a THI over 72. Results confirm that Italian Mediterranean buffalo express a good level of thermo-tolerance, even though exposure to a daily THI over 76 has a deleterious effect on some nutritional and technological properties of milk.

Seeing through the smoke: The effects of wildfire fine particulate matter (PM2.5) exposure on standing and lying behavior in Holstein heifer calves

Wildfires are burning more acres annually, contributing to air pollution across the United States. Air pollutants, such as particulate matter (PM2.5), have health implications for humans and animals, and are known to alter behavior in several species, but effects of wildfire PM2.5 on dairy calf behavior are unknown. The present study aimed to understand how dairy calf standing and lying behavior is affected by wildfire PM2.5. Holstein heifer calves (n = 13) were monitored for the first 90 d of life, concurrent with the 2022 wildfire season. Hourly PM2.5 concentrations and meteorological conditions, which were used to calculate temperature-humidity index (THI), were recorded. Wildfire and wind trajectory mapping was used to determine the contribution of wildfires to spikes in PM2.5. Calf activity data were recorded every minute using accelerometers and analyzed as total hourly and daily standing and lying times, standing and lying bouts, and duration of bouts. Additionally, the responses of calves to the initial 24-h period of each of 2 separate exposures to wildfire smoke were assessed. Wildfire PM2.5 exposure was associated with reduced daily standing time and bout duration, increased daily total lying time, and increased, albeit not significantly, daily standing bouts. Percent of time standing hourly was increased, whereas percent of time lying hourly was decreased by wildfire PM2.5. The initial 24 h of each smoke exposure was characterized by decreased standing and increased lying time, but there was a greater change in behavior during the first event compared with the second event. These results indicate that exposure to wildfire PM2.5 induces a behavioral response, which may diminish with repeated exposures. Future research should aim to understand the health and welfare implications of the behavioral responses to wildfire PM2.5.

Increased heat stress for the population of urbanized areas against the background of global climate change

The combination of high temperature and relative humidity of the atmospheric air creates heat stress, which has a serious impact on the environment, society and the health of the population in urban areas. Using the example of the city of Kyiv, the paper investigated long-term changes in heat stress depending on global climate changes. Averaged monthly long-term climate data of the urban environment were studied, starting from 1981, based on monitoring data using the Copernicus Climate Change Service toolkit and data from the Borys Sreznevsky Central Geophysical Observatory. Predictive dynamics of temperature by conventional and wet bulb was investigated using OriginPro8 software. Data on the dependence of the frequency and unevenness of precipitation during the last decades are presented. The dependences of the value of the heat index (NI) on the temperature and air humidity for different observation periods were obtained. Over the past decade, Kyiv has seen a significant increase in average heat stress and the frequency of days and events with extreme heat stress. According to the obtained forecast estimates, in 2050 the heat index should increase by almost 30%, and the risk to the health of the population in the surrounding area and for workers in the open air will be interpreted as "high" levels at a relative humidity of 80%; "moderate" at a relative humidity of 50% and "low" at a relative humidity of 20%. The forecast temperature dynamics according to the conventional and according to the wet thermometer in the month of July at the end of different years is: 2021–2030 – 24.136°С and 26.24°С; 2030–2050 – 26.371°С and 28.918°С, respectively, with other equal conditions of the urban environment. An additional possibility of influence on the thermal dome appears already at the design stage, thanks to the variability of the placement of the projected buildings on the general plan, and the formation of individual buildings, in the correct area ratio green plantings to stone surfaces of facades and paving. The research data will be useful for the possible reduction of the size of the thermal dome over the city during the planning and reconstruction of the housing stock and the development of climate neutrality measures for the cities of Ukraine.

Effect of temperature-humidity index on the evolution of trade-offs between fertility and production in dairy cattle

BackgroundIn the current context of climate change, livestock production faces many challenges to improve the sustainability of systems. Dairy farming, in particular, must find ways to select animals that will be able to achieve sufficient overall production while maintaining their reproductive ability in environments with increasing temperatures. With future forecasted climate conditions in mind, this study used data from Holstein and Montbeliarde dairy cattle to: (1) estimate the genetic-by-temperature-humidity index (THI) interactions for female fertility, and (2) evaluate the production-fertility trade-off with increasing values of THI.ResultsTwo-trait random regression models were fitted for conception rate (fertility) and test-day protein yield (production). For fertility, genetic correlations between different THI values were generally above 0.75, suggesting weak genotype-by-THI interactions for conception rate in both breeds. However, the genetic correlations between the conception rate breeding values at the current average THI (THI = 50, corresponding to a 24-h average temperature of 8 °C at 50% relative humidity) and their slopes (i.e., potential reranking) for heat stress scenarios (THI > 70), were different for each breed. For Montbeliarde, this correlation tended to be positive (i.e., overall the best reproducers are less affected by heat stress), whereas for Holstein it was approximately zero. Finally, our results indicated a weak antagonism between production and fertility, although for Montbeliarde this antagonism intensified with increasing THI.ConclusionsWithin the range of weather conditions studied, increasing temperatures are not expected to exacerbate the fertility-production trade-off. However, our results indicated that the animals with the best breeding values for production today will be the most affected by temperature increases, both in terms of fertility and production. Nonetheless, these animals should remain among the most productive ones during heat waves. For Montbeliarde, the current selection program for fertility seems to be adequate for ensuring the adaptation of fertility traits to temperature increases, without adverse effects on production. Such a conclusion cannot be drawn for Holstein. In the future, the incorporation of a heat tolerance index into dairy cattle breeding programs would be valuable to promote the selection of animals adapted to future climate conditions.

Heat Transfer by Sweat Droplet Evaporation.

Sweating regulates the body temperature in extreme environments or during exercise. Here, we investigate the evaporative heat transfer of a sweat droplet at the microscale to unveil how the evaporation complexity of a sweat droplet would affect the body's ability to cool under specific environmental conditions. Our findings reveal that, depending on the relative humidity and temperature levels, sweat droplets experience imperfect evaporation dynamics, whereas water droplets evaporate perfectly at equivalent ambient conditions. At low humidity, the sweat droplet fully evaporates and leaves a solid deposit, while at high humidity, the droplet never reaches a solid deposit and maintains a liquid phase residue for both low and high temperatures. This unprecedented evaporation mechanism of a sweat droplet is attributed to the intricate physicochemical properties of sweat as a biofluid. We suppose that the sweat residue deposited on the surface by evaporation is continuously absorbing the surrounding moisture. This route leads to reduced evaporative heat transfer, increased heat index, and potential impairment of the body's thermoregulation capacity. The insights into the evaporative heat transfer dynamics at the microscale would help us to improve the knowledge of the body's natural cooling mechanism with practical applications in healthcare, materials science, and sports science.

Natural shading vs. artificial shading: A comparative analysis of their cooling efficacy in extreme hot weather

Shading, comprising both natural and artificial coverings, is an efficient and effective strategy to reduce heat stress in outdoor environments. Despite its recognized efficiency, there is limited comparative insight into the cooling performance of natural and artificial shading. This study examined the cooling efficacy of two covered walkways and two tree canopies, concerning microclimate conditions by various variables and thermal stress quantified by four thermal indices. Our findings highlight three key points: Firstly, the average cooling effects provided by natural and artificial shading were comparable, including reductions in air temperature (1.42 °C vs. 1.31 °C), mean radiant temperature (15.93 °C vs. 13.71 °C), and Physiological Equivalent Temperature (PET) (9.06 °C vs. 9.70 °C), Universal Thermal Climate Index (UTCI) (4.71 °C vs. 5.08 °C), and Hong Kong Heat Index (HKHI) (2.36 °C vs. 2.50 °C). Secondly, it is inconsistent which shading solution is better for microclimate improvement and heat stress alleviation, which is affected by canopy materials, configurations, and tree species. Thirdly, the four indices presented an inconsistent pattern in heat stress assessment. Notably, PET and UTCI showed similar patterns, while HKHI and modified PET presented lower sensitivity to high heat stress. This study offers valuable insights for urban designers to create sustainable shaded communities and also initiates a discourse for revising local heat warning systems, considering various thermal stress indices.

Genetic analysis of phenotypic indicators for heat tolerance in crossbred dairy cattle

Climate change-induced rise in global temperatures has intensified heat stress on dairy cattle and is contributing to the generally observed low milk productivity. Selective breeding aimed at enhancing animals’ ability to withstand rising temperatures while maintaining optimal performance is crucial for ensuring future access to dairy products. However, phenotypic indicators of heat tolerance are yet to be effectively factored into the objectives of most selective breeding programs. This study investigated the response of milk production to changing heat load as an indication of heat tolerance and the influence of calving season on this response in multibreed dairy cattle performing in three agroecological zones Kenya. First-parity 7-day average milk yield (65 261 milk records) of 1 739 cows were analyzed. Based on routinely recorded weather data that were accessible online, the Temperature-Humidity Index (THI) was calculated and used as a measure of heat load. THI measurements used represented averages of the same 7-day periods corresponding to each 7-day average milk record. Random regression models, including reaction norm functions, were fitted to derive two resilience indicators: slope of the reaction norm (Slope) and its absolute value (Absolute), reflecting changes in milk yield in response to the varying heat loads (THI 50 and THI 80). The genetic parameters of these indicators were estimated, and their associations with average test-day milk yield were examined. There were no substantial differences in the pattern of milk yield response to heat load between cows calving in dry and wet seasons. Animals with ≤50% Bos taurus genes were the most thermotolerant at extremely high heat load levels. Animals performing in semi-arid environments exhibited the highest heat tolerance capacity. Heritability estimates for these indicators ranged from 0.06 to 0.33 and were mostly significantly different from zero (P < 0.05). Slope at THI 80 had high (0.64–0.71) negative correlations with average daily milk yield, revealing that high-producing cows are more vulnerable to heat stress and vice versa. A high (0.63–0.74) positive correlation was observed between Absolute and average milk yield at THI 80. This implied that low milk-producing cows have a more stable milk production under heat-stress conditions and vice versa. The study demonstrated that the slope of the reaction norms and its absolute value can effectively measure the resilience of crossbred dairy cattle to varying heat load conditions. The implications of these findings are valuable in improving the heat tolerance of livestock species through genetic selection.

Variations of heat exhaustion rate of pilgrims with environmental conditions during hajj seasons between 2002 and 2018 in Makkah, Saudi Arabia

Heat exhaustion (HE) is one of the major concerns for medical service providers, especially in hot weather conditions. Every year pilgrims come to Makkah in Saudi Arabia to perform hajj rites which require a lot of physical effort. Makkah has a very hot climate, especially in the summer. Several cases of HE have been reported among pilgrims. The rate of heat exhaustion (HER) among pilgrims was studied using five climatic factors such as temperature (T), relative humidity (RH), heat index (HI), total solar radiation (TSR) and wind speed (WS) during the Hajj seasons between 2002 and 2018 in Makkah. These factors were measured using data collected by the weather stations owned by The Custodian of the Two Holy Mosques Institute for Hajj and Umrah Research at Umm Al-Qura University in Makkah. There is a roughly 11 days difference between solar and lunar years. Occurring in the 12th lunar month of the Islamic calendar, the Hajj is rotating by about 11 days each year. As a result, it will coincide with each month of the solar calendar in a period of about 32 years. Therefore, the HER values ranged between 0.18 per 105 in the winter of 2005 to 35.97 per 105 in the summer of 2018. Simple and multiple linear regression analysis revealed a very high linear relationship among most climate factors and HER (multiple R (MR) ≥ 79 %, R2 ≥ 63 % and P < 10−4). Seven different equation groups of climate factors were applied to predict HER values and showed a very high correlation (MR ≥ 91 %, R2 ≥ 83 % and P ≤ 0.001). Further studies of HER are needed, especially in terms of medical, environmental, demographic, and social sciences in Makkah.

A comprehensive method of researching the tribological efficiency of couplings of parts of nodes, systems and aggregates of cars

In this work, a universal tribometer is proposed to study the tribological efficiency of the couplings of samples and parts. The design of the tribometer made it possible to carry out experimental studies in a wide range of force parameters of the load with their smooth change. A set of characteristics and parameters determined on tribometers during the study of couplings of samples according to the "disk-finger" scheme is given: wear intensity, coefficient of friction, temperature in the contact zone, specific work of destruction, specific energy capacity according to the heat index, electrical criterion for evaluating the structural adaptability of tribo couplings. Modes of friction and wear were determined by the characteristics of changes in the contact electrical resistance parameters: run-in, normal friction and wear, volume destruction. The results of the research of tribological efficiency according to the specified characteristics and parameters are given. For a comparative effect, the samples were strengthened by a complex chemical-thermal method, serial technology and boronization . The results made it possible to identify the characteristic zones of run-in regimes, normal friction and wear, and volumetric destruction. They are confirmed by the received electron microfractographies.

Exposure to ambient temperature and heat index in relation to DNA methylation age: A population-based study in Taiwan

BackgroundClimate change caused an increase in ambient temperature in the past decades. Exposure to high ambient temperature could result in biological aging, but relevant studies in a warm environment were lacking. We aimed to study the exposure effects of ambient temperature and heat index (HI) in relation to age acceleration in Taiwan, a subtropical island in Asia. MethodsThe study included 2,084 participants from Taiwan Biobank. Daily temperature and relative humidity data were collected from weather monitoring stations. Individual residential exposure was estimated by ordinary kriging. Moving averages of ambient temperature and HI from 1 to 180 days prior to enrollment were calculated to estimate the exposure effects in multiple time periods. Age acceleration was defined as the difference between DNA methylation age and chronological age. DNA methylation age was calculated by the Horvath’s, Hannum’s, Weidner’s, ELOVL2, FHL2, phenotypic (Pheno), Skin & blood, and GrimAge2 (Grim2) DNA methylation age algorithms. Multivariable linear regression models, generalized additive models (GAMs), and distributed lag non-linear models (DLNMs) were conducted to estimate the effects of ambient temperature and HI exposures in relation to age acceleration. ResultsExposure to high ambient temperature and HI were associated with increased age acceleration, and the associations were stronger in prolonged exposure. The heat stress days with maximum HI in caution (80-90°F), extreme caution (90-103°F), danger (103-124°F), and extreme danger (>124°F) were also associated with increased age acceleration, especially in the extreme danger days. Each extreme danger day was associated with 571.38 (95 % CI: 42.63–1100.13), 528.02 (95 % CI: 36.16–1019.87), 43.9 (95 % CI: 0.28–87.52), 16.82 (95 % CI: 2.36–31.28) and 15.52 (95 % CI: 2.17–28.88) days increase in the Horvath’s, Hannum’s, Weidner’s, Pheno, and Skin & blood age acceleration, respectively. ConclusionHigh ambient temperature and HI may accelerate biological aging.

Heat index extremes increasing several times faster than the air temperature

Abstract

Heat stress measuring methods in dairy cows

The most widely used predictor to assess the incidence of thermal stress in livestock is THI, the temperature humidity index. However, it is an indicator that disregards the individual animal and the specific farm conditions. This review aims to list and summarize other thermal stress predictor factors, by using non-invasive and cost-effective strategies, in particular with the aid of Precision Livestock Farming technologies. When it comes to dairy animals the metabolic load is already increased by milk production, so the effect of heat stress can exacerbate the overall welfare of the cow. Therefore, the animals enact copying mechanisms that may result in physiological, behavioral and productive alterations. Those animal-based parameters can be used as early predictors of heat stress, allowing the farmer to collect real time data and address the condition operating management strategies in order to prevent further detrimental effect on the performance and consequent economic losses.

Microclimate Impacts of Land Cover Types in Halu Oleo University Botanical Garden and Its Surroundings

Halu Oleo University (UHO) Botanical Garden is one of the green open spaces that contribute to maintaining climate stability and environmental comfort in Kendari City, along with the high land use change due to increased population and city progress. The study aimed to determine the effect of land cover types on microclimate in UHO Botanical Garden and its surroundings. The research was conducted from June 2021 to January 2022. The research was conducted on three types of vegetation land cover. The variables measured were microclimate, including light intensity, temperature, relative humidity, and temperature humidity index. Measurements were conducted in the morning, afternoon, and evening. The method used was descriptive quantitative and statistical analysis using the analysis of variance and the least significant difference (LSD) test. The results showed that the microclimatic conditions of UHO Botanical Garden in tree-dominant land cover are more comfortable and significantly different from grass-dominant and settlement-dominant, but they are not significantly different between grass-dominant and settlement-dominant. This fact indicates the importance of the conservation of tree vegetation and the need for supervision so that there is no diversion of functions into settlements to maintain the preservation and sustainability of UHO Botanical Garden as one of the green open spaces that control climate stability and environmental comfort in Kendari City. Keywords: botanical garden, microclimate, settlement, temperature humidity index, vegetation

Infrared thermography as a potential non-invasive tool to study seasonal stress in late gestation Sahiwal cows and their neonate calves

Stress triggers a multitude of physiological responses including alterations in surface temperature aimed at maintaining homeostasis of animal. The present study was undertaken to evaluate the comparative seasonal effect of thermal stress on body surface temperature during the critical period of late gestation and early life. For this, late gestational Sahiwal cows (n=48) were selected and categorized into four groups: natural heat stressed (NHS), cooling treated (CLT), spring and winter groups, and their neonate calves born in summer (IUHS-intra uterine heat stressed and IUCL-intra uterine cooled), spring and winter season. The thermal profile obtained from infrared thermography (IRT) showed a trend of surface temperature for each region examined over varied THI (temperature humidity index). Body surface temperature in NHS was significantly higher, followed by spring, CLT and least in winter group cows. Within the group, study revealed numerically high surface temperature of eye, front and udder on the day of parturition, while slightly lower temperature of flank portion. NHS, CLT and spring cows had non-significant variations in udder temperature. Insulation breakage from the legs at a colder temperature was observed. In neonates, significantly high surface temperature was observed in IUHS, followed by IUCL and spring calves, while significantly low surface temperature in winter calves. Thus, cooling treatment in the late gestation significantly lowered body surface temperature in both dams and calves. Further, it is also concluded that out of different anatomical regions, eye and feet temperature is the most reliable indicator for assessing seasonal stress with changing THI.

Animal welfare on Argentinean dairy farms based on the Welfare Quality® protocol framework

Animal welfare is a multidimensional concept that comprises animal health, mental state and natural living conditions and plays an essential role in dairy production. On dairy farms, animal welfare can be assessed with different available protocols. The goal of this study was to describe the animal welfare strengths and hazards of dairy farms in Argentina using the Welfare Quality® protocol as a framework. We conducted a literature search using the Scopus database to find articles related to the measures included in the protocol for Argentinean farms. Furthermore, we included data from national statistics. The data available were grouped according to the four principles of the protocol: good feeding, good housing, good health, and appropriate behavior. The results suggest that cows are well nourished; however, water provision is limited because grazing cows need to walk long distances, between 244 m and 460 m, to access a water point. Heat stress is a notable constraint affecting the welfare of cows, as the temperature-humidity index is greater than 72 for at least 100 days during the year. The prevalence of lameness and downer cows was estimated to be 2.2% and 0.7%, respectively, which are below the thresholds for ensuring good welfare. The annual average somatic cell count was 385,000/ml, close to the cutoff recommended for good health. The mortality rate of the cows was higher than recommended. The main strength of Argentinean dairy farms in relation to animal welfare is access to pasture throughout the year for 90% of the farms.

Validation of a temperature-humidity index (Humidex) in evaluating heat stress at a tile factory in Iran.

Several heat indices have been developed in industrial health, but each has its limitations. The objective of this article is to determine the validity and applicability of a temperature-humidity index, named Humidex compared with the Standard Wet-Bulb Globe Temperature (WBGT) index (ISO 7243). This cross-sectional study was conducted in the summer of 2019, in a tile factory in the west of Iran. 59 measurements were performed in 8 different workstations. Environmental parameters including natural wet bulb temperature (Tnw), dry bulb temperature (Ta), globe bulb temperature (Tg), and heat stress (WBGT) were measured. Humidex was calculated according to an equation. SPSS software (version 16) was used for data analysis. There was a high correlation between Humidex and WBGT in the estimation of heat stress (R=0.912, P<0.001). The Kappa Coefficient between Humidex and WBGT was 0.298, P=0.001. Humidex is highly correlated with WBGT. Humidex can be used instead of the WBGT index, especially in hot and humid environments.