scholarly journals Modeling of Heat Stress in Sows Part 2: Comparison of Various Thermal Comfort Indices

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1498
Author(s):  
Mengbing Cao ◽  
Chao Zong ◽  
Yanrong Zhuang ◽  
Guanghui Teng ◽  
Shengnan Zhou ◽  
...  
Keyword(s):  
Heat Stress ◽  
Thermal Environment ◽  
Production Performance ◽  
Heat Index ◽  
Growth Stages ◽  
Equivalent Temperature ◽  
Thermal Indices ◽  
Important Indicator ◽  
Thermal Index ◽  
Heat Indices

Heat stress has an adverse effect on the production performance of sows, and causes a large economic loss every year. The thermal environment index is an important indicator for evaluating the level of heat stress in animals. Many thermal indices have been used to analyze the environment of the pig house, including temperature and humidity index (THI), effective temperature (ET), equivalent temperature index of sows (ETIS), and enthalpy (H), among others. Different heat indices have different characteristics, and it is necessary to analyze and compare the characteristics of heat indices to select a relatively suitable heat index for specific application. This article reviews the thermal environment indices used in the process of sow breeding, and compares various heat indices in four ways: (1) Holding the value of the thermal index constant and analyzing the equivalent temperature changes caused by the relative humidity. (2) Analyzing the variations of ET and ETIS caused by changes in air velocity. (3) Conducting a comparative analysis of a variety of isothermal lines fitted to the psychrometric chart. (4) Analyzing the distributions of various heat index values inside the sow barn and the correlation between various heat indices and sow heat dissipation with the use of computational fluid dynamics (CFD) technology. The results show that the ETIS performs better than other thermal indices in the analysis of sows’ thermal environment, followed by THI2, THI4, and THI7. Different pigs have different heat transfer characteristics and different adaptability to the environment. Therefore, based on the above results, the following suggestions have been given: The thermal index thresholds need to be divided based on the adaptability of pigs to the environment at different growth stages and the different climates in different regions. An appropriate threshold for a thermal index can provide a theoretical basis for the environmental control of the pig house.

scholarly journals Modeling of Heat Stress in Sows—Part 1: Establishment of the Prediction Model for the Equivalent Temperature Index of the Sows

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1472
Author(s):  
Mengbing Cao ◽  
Chao Zong ◽  
Xiaoshuai Wang ◽  
Guanghui Teng ◽  
Yanrong Zhuang ◽  
...  
Keyword(s):  
Heat Stress ◽  
Relative Humidity ◽  
Skin Temperature ◽  
Air Temperature ◽  
Physiological Response ◽  
Equivalent Temperature ◽  
Air Velocity ◽  
Thermal Indices ◽  
Thermal Index ◽  
Temperature Index

Heat stress affects the estrus time and conception rate of sows. Compared with other life stages of pigs, sows are more susceptible to heat stress because of their increased heat production. Various indicators can be found in the literature assessing the level of heat stress in pigs. However, none of them is specific to assess the sows’ thermal condition. Moreover, thermal indices are mainly developed by considering partial environment parameters, and there is no interaction between the index and the animal’s physiological response. Therefore, this study aims to develop a thermal index specified for sows, called equivalent temperature index for sows (ETIS), which includes parameters of air temperature, relative humidity and air velocity. Based on the heat transfer characteristics of sows, multiple regression analysis is used to combine air temperature, relative humidity and air velocity. Environmental data are used as independent variables, and physiological parameters are used as dependent variables. In 1029 sets of data, 70% of the data is used as the training set, and 30% of the data is used as the test set to create and develop a new thermal index. According to the correlation equation between ETIS and temperature-humidity index (THI), combined with the threshold of THI, ETIS was divided into thresholds. The results show that the ETIS heat stress threshold is classified as follows: suitable temperature ETIS < 33.1 °C, mild temperature 33.1 °C ≤ ETIS < 34.5 °C, moderate stress temperature 34.5 °C ≤ ETIS < 35.9 °C, and severe temperature ETIS ≥ 35.9 °C. The ETIS model can predict the sows’ physiological response in a good manner. The correlation coefficients R of skin temperature was 0.82. Compared to early developed thermal indices, ETIS has the best predictive effect on skin temperature. This index could be a useful tool for assessing the thermal environment to ensure thermal comfort for sows.

scholarly journals Comparison of Thermal Comfort between Sapporo and Tokyo—The Case of the Olympics 2020

Atmosphere ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 444
Author(s):  
Yuting Wu ◽  
Kathrin Graw ◽  
Andreas Matzarakis
Keyword(s):  
Heat Stress ◽  
Thermal Comfort ◽  
Olympic Games ◽  
Physiologically Equivalent Temperature ◽  
Precipitation Rate ◽  
Equivalent Temperature ◽  
Thermal Indices ◽  
Climate Conditions ◽  
Northern City ◽  
The Olympic Games

Weather and climate conditions can be decisive regarding travel plans or outdoor events, especially for sport events. The Olympic Games 2020, postponed to 2021, will take place in Tokyo at a time which is considered to be the hottest and most humid time of the year. However, a part of the athletic competitions is relocated to the northern city Sapporo. Therefore, it is important to quantify thermal comfort for different occasions and destinations and make the results accessible to visitors and sport attendees. The following analysis will quantify and compare thermal comfort and heat stress between Sapporo and Tokyo using thermal indices like the Physiologically Equivalent Temperature and the modified Physiologically Equivalent Temperature (PET and mPET). The results reveal different precipitation patterns for the cities. While a higher precipitation rate appears in Sapporo during winter, the precipitation rate is higher in Tokyo during summer. PET and mPET exhibit a greater probability of heat stress conditions in Tokyo during the Olympic Games, whereas Sapporo has more moderate values for the same period. The Climate-Tourism/Transfer-Information-Scheme (CTIS) integrates and simplifies climate information and makes them comprehensible for non-specialists. The CTIS of Tokyo illustrates lower suitable conditions for “Heat stress”, “Sunny days” and “Sultriness”. Transferring parts of the athletics competition to a northern city is thus more convenient for athletes, staff members and spectators. Hence, heat stress can be avoided and an acceptable outdoor stay is ensured. Overall, this quantification and comparison of the thermal conditions in Sapporo and Tokyo reveal limitations but also possibilities for the organizers of the Olympic Games. Furthermore it can be used to raise awareness for promoting or arranging countermeasures and heat mitigation at specific events and destinations, if necessary.

scholarly journals Human-biometeorological assessment of Kharkiv (Ukraine) in the summer season

2021 ◽  
Vol 54/55 (54/55) ◽  
pp. 43-54
Author(s):  
Olga Shevchenko ◽  
Sergiy Snizhko ◽  
Mariia Matviienko
Keyword(s):  
Heat Stress ◽  
Heat Waves ◽  
Average Frequency ◽  
Summer Season ◽  
Equivalent Temperature ◽  
Thermal Index ◽  
Heat Adaptation ◽  
The City ◽  
Rayman Model ◽  
Recreation And Tourism

The objective of this research is to assess the bioclimate of the city of Kharkiv in the summer season using the human thermal index of physiologically equivalent temperature (PET). The RayMan model has been used to obtain PET values. The results suggest that most days in Kharkiv during the summer are characterized by heat stress of various intensity 65.7% in June, 84.6% in July, 77.1% in August. The average frequency of comfortable weather is very low, varying from 12.6 to 25%. During heat waves, the frequency of days in Kharkiv with heat stress increases significantly, amounting to 96.3%. The results of the Kharkiv bioclimate assessment using PET may be used to create measures for heat adaptation and develop infrastructure for recreation and tourism in the city during hot periods.

scholarly journals Evolution of Heat Index (HI) and Physiological Equivalent Temperature (PET) Index at Mumbai and Pune Cities, India

MAUSAM ◽  
2021 ◽  
Vol 72 (4) ◽  
pp. 915-934
Author(s):  
MANASI DESAI ◽  
ASHISH NAVALE ◽  
AMIT G. DHORDE
Keyword(s):  
Heat Stress ◽  
Meteorological Parameters ◽  
Monsoon Season ◽  
Ambient Air ◽  
Heat Index ◽  
Stepwise Multiple Regression ◽  
Main Concern ◽  
Equivalent Temperature ◽  
Physiological Equivalent Temperature ◽  
Pet Index

In the present study, trends in heat stress during summer and monsoon season months were assessed for two cities, Pune and Mumbai, for the period of 47 years from 1969 to2015 with the application of empirically derived Heat Index (HI) and rational heat balance based Physiological Equivalent Temperature (PET) index. A stepwise multiple regression analysis was applied to determine contributing meteorological parameters responsible for changes in heat stress incidences. The study reveals a considerable increase in heat stress during the summer months over Mumbai compared to Pune city. Similarly, during the end months of monsoon season, thermal discomfort conditions aggravate over both the cities, with statistically significant rising trends. The actual identification and categorization of thermally discomfortable days during the study period in accordance with the Heat Index were moderate. They remained consistent in Pune during summer, however, in monsoon, heat stress incidences were meager. While at Mumbai days with 'High' and 'Very High,' heat stress have increased towards recent years. Categorization according to PET index depicted conspicuous presence of 'Strong' and 'Extreme heat stress' at Pune, while at Mumbai, 'Warm' and 'Hot' days portrayeda slight increase.  The assessment of meteorological parameters depicted that increased humidity and temperature were the main concern for the increase in heat stress over Mumbai. In contrast, mean radiant temperature, ambient air temperature with restricted wind speed leading to high sensible heat may be responsible for the significant increasing trend in PET. The study infers that both the cities are vulnerable to escalating heat stress and may have adverse implications on the health of city dwellers. 

Numerical Study of Thermal Comfort with the Effects of Canopy Transparency

2014 ◽  
Vol 919-921 ◽  
pp. 1677-1680
Author(s):  
Choul Woong Kwon ◽  
Sung Woo Shin
Keyword(s):  
Thermal Comfort ◽  
Urban Areas ◽  
Thermal Environment ◽  
Numerical Study ◽  
Complex Surface ◽  
Outdoor Thermal Comfort ◽  
Thermal Indices ◽  
Physiological Equivalent Temperature ◽  
Thermal Index ◽  
Radiation Fluxes

Several complex thermal indices (e.g. PMV and PET) were developed in the last decades to describe the quantify the thermal environment of humans and the energy fluxes between body and environment. Compared to open spaces the complex surface structure of urban areas creates an environment with special microclimatic characteristics, which have a dominant effect on the energy balance of the human body. In this study, outdoor thermal comfort conditions are examined through numerical model with different transparency ratios in canopy. The intensity of radiation fluxes is dependent on several factors, such as orientation, size and transparency of canopy. Special emphasis is given to the human-biometeorological assessment of the microclimate of building element (canopy) through the application of the thermal index PET (Physiological Equivalent Temperature). The analysis is carried out by the utilization of Ecotect and RayMan software.

scholarly journals Evaluation of Thermal Indices as the Indicators of Heat Stress in Dairy Cows in a Temperate Climate

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2459
Author(s):  
Geqi Yan ◽  
Hao Li ◽  
Zhengxiang Shi
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Systematic Evaluation ◽  
Temperate Climate ◽  
Climate Index ◽  
Future Research ◽  
Equivalent Temperature ◽  
Thermal Indices ◽  
Actual Performance ◽  
Temperature Index

Many thermal indices (TIs) have been developed to quantify the severity of heat stress in dairy cows. Systematic evaluation of the representative TIs is still lacking, which may cause potential misapplication. The objectives of this study were to evaluate the theoretical and actual performance of the TIs in a temperate climate. The data were collected in freestall barns at a commercial dairy farm. The heat transfer characteristics of the TIs were examined by equivalent air temperature change (ΔTeq). One-way ANOVA and correlation were used to test the relationships between the TIs and the animal-based indicators (i.e., rectal temperature (RT), respiration rate (RR), skin temperature (ST), and eye temperature (ET)). Results showed that the warming effect of the increased relative humidity and the chilling effect of the increased wind speed was the most reflected by the equivalent temperature index (ETI) and the comprehensive climate index (CCI), respectively. Only the equivalent temperature index for cows (ETIC) reflected that warming effect of solar radiation could obviously increase with increasing Ta. The THI and ETIC showed expected relationships with the RT and RR, whereas the CCI and ETIC showed expected relationships with the ST and ET. Moreover, CCI showed a higher correlation with RT (r = 0.672, p < 0.01), ST(r = 0.845, p < 0.01), and ET (r = 0.617, p < 0.01) than other TIs (p < 0.0001). ETIC showed the highest correlation with RR (r = 0.850, p < 0.01). These findings demonstrated that the CCI could be the most promising thermal index to assess heat stress for housed dairy cows. Future research is still needed to develop new TIs tp precisely assess the microclimates in cow buildings.

scholarly journals New and Old Indices for Evaluating Heat Stress in an Indoor Environment: Some Considerations. Comment on Kownacki, L.; Gao, C.; Kuklane, K.; Wierzbicka, A. Heat Stress in Indoor Environments of Scandinavian Urban Areas: A Literature Review. Int. J. Environ. Res. Public Health 2019, 16 (4), 560. doi:10.3390/ijerph16040560

2019 ◽  
Vol 16 (8) ◽  
pp. 1444 ◽  
Author(s):  
Francesco Chirico ◽  
Nicola Magnavita
Keyword(s):  
Heat Stress ◽  
Urban Areas ◽  
Heat Index ◽  
Indoor Environments ◽  
Wet Bulb Globe Temperature ◽  
Comfort Index ◽  
Predicted Heat Strain ◽  
Thermal Work ◽  
Globe Temperature ◽  
Heat Indices

In their review, Kownacki et al. showed some practical and easy to use workplace heat indices that are useful for indoor environments, namely the “Wet Bulb Globe Temperature” (WBGT), the “Predicted Heat Strain” (PHS) model, the “Thermal Work Limit” (TWL), the “Equivalent Temperature” (ET) and the thermal comfort index “PMV/PPD”. In this letter, the authors explain why the modified PMV/PPD method together with the indices combining temperature with humidity, such as the “Humidex Index” and the “Heat Index”, could be a more feasible and useful tool for evaluating potential thermal stress in indoor environments for both the occupational and general population.

scholarly journals Heat Stress and Goat Welfare: Adaptation and Production Considerations

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1021
Author(s):  
Veerasamy Sejian ◽  
Mullakkalparambil V. Silpa ◽  
Mini R. Reshma Nair ◽  
Chinnasamy Devaraj ◽  
Govindan Krishnan ◽  
...  
Keyword(s):  
Heat Stress ◽  
Body Condition Score ◽  
Heat Exposure ◽  
Stocking Density ◽  
Production Performance ◽  
Farm Animals ◽  
Meat Production ◽  
Important Species ◽  
Tropical Regions ◽  
Tropical Climates

This review attempted to collate and synthesize information on goat welfare and production constraints during heat stress exposure. Among the farm animals, goats arguably are considered the best-suited animals to survive in tropical climates. Heat stress was found to negatively influence growth, milk and meat production and compromised the immune response, thereby significantly reducing goats’ welfare under extensive conditions and transportation. Although considered extremely adapted to tropical climates, their production can be compromised to cope with heat stress. Therefore, information on goat adaptation and production performance during heat exposure could help assess their welfare. Such information would be valuable as the farming communities are often struggling in their efforts to assess animal welfare, especially in tropical regions. Broadly three aspects must be considered to ensure appropriate welfare in goats, and these include (i) housing and environment; (ii) breeding and genetics and (iii) handling and transport. Apart from these, there are a few other negative welfare factors in goat rearing, which differ across the production system being followed. Such negative practices are predominant in extensive systems and include nutritional stress, limited supply of good quality water, climatic extremes, parasitic infestation and lameness, culminating in low production, reproduction and high mortality rates. Broadly two types of methodologies are available to assess welfare in goats in these systems: (i) animal-based measures include behavioral measurements, health and production records and disease symptoms; (ii) resources based and management-based measures include stocking density, manpower, housing conditions and health plans. Goat welfare could be assessed based on several indicators covering behavioral, physical, physiological and productive responses. The important indicators of goat welfare include agonistic behavior, vocalization, skin temperature, body condition score (BCS), hair coat conditions, rectal temperature, respiration rate, heart rate, sweating, reduced growth, reduced milk production and reduced reproductive efficiency. There are also different approaches available by which the welfare of goats could be assessed, such as naturalistic, functional and subjective approaches. Thus, assessing welfare in goats at every production stage is a prerequisite for ensuring appropriate production in this all-important species to guarantee optimum returns to the marginal and subsistence farmers.

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