Analysis of thermal discomfort associated with synoptic conditions in the city of Pelotas, southernmost region of Brazil.

Here, we evaluated the influence of outdoor environmental conditions (synoptic weather conditions) on human thermal discomfort in the five macro-regions of Pelotas city, located in the southernmost region of Brazil. To do this, meteorological sensors (HOBO MX2301A) were installed outside the residences to measure the air temperature, dew point temperature, and relative humidity between 18 January and 20 August 2019. Two well-established simplified biometeorological indices were examined seasonally: (i) humidex for the summer months and (ii) effective temperature as a function of wind for the autumn and winter months. Our findings showed seasonal differences related to human thermal discomfort and outdoor environmental conditions. The thermal discomfort was highest in the afternoons during the summer months and at night during the winter months. The seasonal variation in human thermal discomfort was highly associated with the meteorological conditions. In summer, the presence of the South Atlantic Subtropical Anticyclone (SASA) contributed to heat stress. The SASA combined with the continent's low humidity contributed to the perceived sensation of thermal discomfort. In the winter, thermal discomfort was associated with the decrease in air humidity caused by high atmospheric pressure systems, which led to a decrease in both air temperature and air moisture content. Our findings suggest that a better understanding of the complex interplay between outdoor environmental factors and human thermal comfort is needed in order to mitigate the negative effects of thermal discomfort.

Thermal comfort conditions at microclimate scale and surface urban heat island in a tropical city: A study on João Pessoa city, Brazil.

Surface urban heat islands (SUHIs) are one of the most studied phenomena in urban climates because they generate problems for the well-being of the urban population. This study analyzed the thermal comfort conditions at microclimate scale and SUHI for João Pessoa city, Brazil. Micrometeorological data (temperature and air humidity data) collected at 10 stations in 2011 and 2018 were used to calculate Thom's discomfort index (TDI) for João Pessoa city. Satellite images from Landsat 5/TM for 1991, 2006, and 2010 and Landsat 8/OLI for 2018 were used for land use and land cover classification and to identify SUHI. The obtained results highlighted that the SUHI area in João Pessoa city was 26 km2 and that almost half of the heat island area was concentrated in the Geisel, Aeroclube, Valentina, Distrito Industrial, Cristo Redentor, and Mangabeira neighborhoods. Regarding the micrometeorological data, higher values were obtained for 2018 in the dry periods (summer) and during the day. Based on the results, a considerable increase in discomfort during the daytime was observed in urbanized areas of the city from 2010 - 2018 due to the increase in the average temperature in João Pessoa between 1991 and 2018.

Valuation of the human thermal discomfort index for the five Brazilian regions in the period of El Niño-Southern Oscillation (ENSO).

Brazil is an extensive country with five administrative regions that have different climates, mainly due to their geographic locations. The El Niño-Southern Oscillation influences the regime of temperature and precipitation of the Brazilian regions, which can directly affect the thermal discomfort of the population. The objective of this study was to evaluate the human thermal discomfort index (HDI) in the five regions of Brazil for El Niño, La Niña, and neutral years from 1979 to 2017, as well as the influence of the degree of intensity of the Pacific Ocean anomaly in the thermal conditions of the Brazilian regions. Monthly data on air temperature and dewpoint temperature obtained from the ERA-Interim reanalysis were used. The HDI was calculated using specific equations. The results were analyzed by means of composition fields. From the results, it was possible to conclude that the El Niño and La Niña phenomena influence the HDI of the Brazilian regions. El Niño increases the discomfort due to the heat and the La Niña causes them to decrease. This study is important since these phenomena, by influencing thermal conditions, directly affect the well-being and health of the Brazilian population.

Estresse térmico na reprodução equina / Thermal stress in equine reproduction

Estudos sobre estresse térmico em equinos, geralmente envolvem condições induzidas pelo exercício físico intenso, assim como as alterações fisiológicas que comtemplam o efeito do ambiente em geral são relacionadas ao fotoperíodo e não ao efeito da temperatura como acontece com maior frequência em outras espécies. Verifica-se uma necessidade de maior compreensão dos efeitos deletérios do estresse térmico no desempenho reprodutivo desta espécie, visto que a produção de potros saudáveis é o objetivo de um programa reprodutivo e em geral a principal fonte de retorno econômico da atividade. Esse fato ganha ainda mais relevância diante das condições climáticas e de criação presentes nos trópicos, além da atividade reprodutiva da espécie equina depender de períodos de alta luminosidade ambiental, que coincidem com as maiores temperaturas. O presente trabalho tem por objetivo demonstrar como o estresse térmico ambiental pode promover a redução da fertilidade em fêmeas equinas e alertar para a necessidade de estudos completos envolvendo o tema.(AU)

Studies on thermal stress in equines usually involve conditions induced by intense physical exercise, as well as the physiological changes that contemplate the effect of the environment in general are related to the photoperiod and not to the effect of temperature as it in other species. We need a better understanding of the deleterious effects of thermal stress on the reproductive performance of this species, since the production of healthy foals is generally the objective of a reproductive program and the main source of economic return of the activity. This fact is even more relevant given the climatic and breeding conditions in the tropics, and the reproductive activity of the equine species take place on periods of high luminosity, which coincide with higher temperatures. The present review aims to demonstrate how the environmental thermal stress can promote the reduction of the fertility in equine females and to alert to the necessity of complete studies involving the theme.(AU)

Estresse térmico na reprodução equina / Thermal stress in equine reproduction

Estudos sobre estresse térmico em equinos, geralmente envolvem condições induzidas pelo exercício físico intenso, assim como as alterações fisiológicas que comtemplam o efeito do ambiente em geral são relacionadas ao fotoperíodo e não ao efeito da temperatura como acontece com maior frequência em outras espécies. Verifica-se uma necessidade de maior compreensão dos efeitos deletérios do estresse térmico no desempenho reprodutivo desta espécie, visto que a produção de potros saudáveis é o objetivo de um programa reprodutivo e em geral a principal fonte de retorno econômico da atividade. Esse fato ganha ainda mais relevância diante das condições climáticas e de criação presentes nos trópicos, além da atividade reprodutiva da espécie equina depender de períodos de alta luminosidade ambiental, que coincidem com as maiores temperaturas. O presente trabalho tem por objetivo demonstrar como o estresse térmico ambiental pode promover a redução da fertilidade em fêmeas equinas e alertar para a necessidade de estudos completos envolvendo o tema.

Studies on thermal stress in equines usually involve conditions induced by intense physical exercise, as well as the physiological changes that contemplate the effect of the environment in general are related to the photoperiod and not to the effect of temperature as it in other species. We need a better understanding of the deleterious effects of thermal stress on the reproductive performance of this species, since the production of healthy foals is generally the objective of a reproductive program and the main source of economic return of the activity. This fact is even more relevant given the climatic and breeding conditions in the tropics, and the reproductive activity of the equine species take place on periods of high luminosity, which coincide with higher temperatures. The present review aims to demonstrate how the environmental thermal stress can promote the reduction of the fertility in equine females and to alert to the necessity of complete studies involving the theme.

Simple physiological indicators of young goats bred in extensive system

The aim of this study was to evaluate the influence of day shift on physiological variables of young goats bred in an extensive system. Ten females of undefined racial pattern were used, with a mean age of 5 months, distributed in a completely randomized design, with two treatments (morning and afternoon shift) and 10 replications per treatment. The environmental variables were collected through a digital thermo-hygrometer. Respiratory and heart rate, and rectal temperature were measured. During the experimental period the averages of the air temperature and relative humidity, and the black globe-humidity index (BGHI) were of 38.80 ºC, 25.76% and 78.11, respectively. It was observed effect (P<0.05) of day shift on all physiological variables, with highest averages observed in the afternoon shift. The animals increased the respiratory and heart rate during the day periods to be able to maintain the rectal temperature within limits considered normal for this species.

Simple physiological indicators of young goats bred in extensive system

The aim of this study was to evaluate the influence of day shift on physiological variables of young goats bred in an extensive system. Ten females of undefined racial pattern were used, with a mean age of 5 months, distributed in a completely randomized design, with two treatments (morning and afternoon shift) and 10 replications per treatment. The environmental variables were collected through a digital thermo-hygrometer. Respiratory and heart rate, and rectal temperature were measured. During the experimental period the averages of the air temperature and relative humidity, and the black globe-humidity index (BGHI) were of 38.80 ºC, 25.76% and 78.11, respectively. It was observed effect (P<0.05) of day shift on all physiological variables, with highest averages observed in the afternoon shift. The animals increased the respiratory and heart rate during the day periods to be able to maintain the rectal temperature within limits considered normal for this species.(AU)

The Brazilian semi-arid environment influences the physiological responses of goats / O ambiente semiárido brasileiro influencia as respostas fisiológicas de caprinos

In this review, we compile information about the physiologic responses of goats to north-eastern Brazils semiarid environment and suggest some strategies to avoid the thermal discomfort of these small ruminants. Due to recent weather changes, the number of studies seeking to improve animal welfare has intensified to minimize the economic losses on animal production in the tropics. Among the climatic variables, the high room temperature, air humidity, and direct solar radiation are the main causes of physiological discomfort in animals that decrease their productivity. Therefore, it is very important to study the components that interact in the thermoregulation process, the consequences of disequilibrium in this process, and ways to ease these effects, aiming to provide thermal comfort to and seek the animal welfare of the animals. Therefore, it is essential to know the interaction between animals and the environment and the adaptability of the species and breeds that are exploited to make decisions about farming systems and management strategies to maximize productivity.

Nesta revisão, nós compilamos informações sobre as respostas fisiológicas de caprinos para o ambiente semiárido do nordeste do Brasil e sugerir algumas estratégias para evitar o desconforto térmico destes pequenos ruminantes. Devido a mudanças climáticas recentes, o número de estudos que procuram melhorar bem-estar animal tem intensificado para minimizar as perdas econômicas na produção animal nos trópicos. Entre as variáveis climáticas, a alta temperatura ambiente, umidade do ar e radiação solar direta são as principais causas de desconforto fisiológico em animais que diminuem sua produtividade. Assim, é muito importante estudar os componentes que interagem no processo de termorregulação, as consequências do desequilíbrio neste processo, e maneiras de aliviar estes efeitos, com o objetivo de proporcionar conforto térmico para buscar o bem-estar animal dos animais. Portanto, é essencial conhecer a interação entre os animais e o ambiente e da capacidade de adaptação das espécies e raças que são exploradas para tomar decisões sobre os sistemas e estratégias de gestão agrícola para maximizar a produtividade.

The Brazilian semi-arid environment influences the physiological responses of goats / O ambiente semiárido brasileiro influencia as respostas fisiológicas de caprinos

In this review, we compile information about the physiologic responses of goats to north-eastern Brazils semiarid environment and suggest some strategies to avoid the thermal discomfort of these small ruminants. Due to recent weather changes, the number of studies seeking to improve animal welfare has intensified to minimize the economic losses on animal production in the tropics. Among the climatic variables, the high room temperature, air humidity, and direct solar radiation are the main causes of physiological discomfort in animals that decrease their productivity. Therefore, it is very important to study the components that interact in the thermoregulation process, the consequences of disequilibrium in this process, and ways to ease these effects, aiming to provide thermal comfort to and seek the animal welfare of the animals. Therefore, it is essential to know the interaction between animals and the environment and the adaptability of the species and breeds that are exploited to make decisions about farming systems and management strategies to maximize productivity.(AU)

Nesta revisão, nós compilamos informações sobre as respostas fisiológicas de caprinos para o ambiente semiárido do nordeste do Brasil e sugerir algumas estratégias para evitar o desconforto térmico destes pequenos ruminantes. Devido a mudanças climáticas recentes, o número de estudos que procuram melhorar bem-estar animal tem intensificado para minimizar as perdas econômicas na produção animal nos trópicos. Entre as variáveis climáticas, a alta temperatura ambiente, umidade do ar e radiação solar direta são as principais causas de desconforto fisiológico em animais que diminuem sua produtividade. Assim, é muito importante estudar os componentes que interagem no processo de termorregulação, as consequências do desequilíbrio neste processo, e maneiras de aliviar estes efeitos, com o objetivo de proporcionar conforto térmico para buscar o bem-estar animal dos animais. Portanto, é essencial conhecer a interação entre os animais e o ambiente e da capacidade de adaptação das espécies e raças que são exploradas para tomar decisões sobre os sistemas e estratégias de gestão agrícola para maximizar a produtividade.(AU)

Thermoregulatory traits of crossbred cattle Holstein x Gir in southern of Piauí state / Características termorreguladoras de bovinos mestiços Holandês x Gir no sul do estado do Piauí

In this work we aimed to evaluate the thermoregulatory traits of crossbred cattle Holstein x Gir under climatic influence during the morning and afternoon shifts of the raining season of the year, in southern of Piaui state. This study was carried out at the experimental farm of the Federal University of Piaui (UFPI), Campus Professora Cinobelina Elvas (CPCE), situated in Bom Jesus city, in Piaui state. Ten cows in lactation were used and respiratory and cardiac frequencies, rectal temperature and sweating rate were measured. The physical analysis of the thermal environment of the install was acquired in the weather station of the UFPIs campus, which registered the temperature and air relative humidity. The wet bulb globe temperature index (WBGTI) was obtained by a thermometer inserted into a black globe. There was significant difference (P 0.05) for all the weather variables, highlighting the air temperature, which had higher value in the afternoon shift (30.41 C). A significant effect (P 0.05) was observed for the physiological variables respiratory rate and sweating rate, in which higher values were measured during the afternoon shift, being respectively 51.59 mov./min. and 104.69 g/m/h, probably because this shift showed the highest values for air temperature. The animals evaluated in this study showed a certain level of thermal discomfort, mainly in the afternoon shift.

O objetivo deste trabalho é avaliar as característicastermorreguladoras de bovinos mestiços Holandês x Gir sobinfluência climática durante os turnos manhã e tarde doperíodo chuvoso do ano, no sul do estado do Piauí. Estetrabalho foi conduzido na fazenda experimental daUniversidade Federal do Piauí (UFPI), Campus ProfessoraCinobelina Elvas (CPCE), localizado na cidade de BomJesus, estado do Piauí. Foram utilizadas dez vacas em lactação e mensuradas as frequências respiratória e cardíaca, temperatura retal e a taxa de sudação. A análise física do ambiente térmico da instalação foi adquirida na estação meteorológica do campus da UFPI, que registrou a temperatura e umidade do ar. O índice de temperatura de globo e umidade (ITGU) foi obtido através de um termômetro inserido em um globo negro. Houve diferença significativa (P<0,05) para todas as variáveis meteorológicas, destacando-se a temperatura do ar, que teve um maior valor no turno da tarde (30,41 °C). Para as variáveis fisiológicas foi observado efeito significativo (P<0,05) para a frequência respiratória e a taxa de sudação nas quais valores maiores destas variáveis foram mensurados no turno da tarde, sendo 51,59 mov./min. e 104,69 g/m/h respectivamente, provavelmente por este turno ter apresentado maiores valores de temperatura do ar. Os animais apresentaram certo nível de desconforto térmico, principalmente no turno da tarde.

Thermoregulatory traits of crossbred cattle Holstein x Gir in southern of Piauí state / Características termorreguladoras de bovinos mestiços Holandês x Gir no sul do estado do Piauí

In this work we aimed to evaluate the thermoregulatory traits of crossbred cattle Holstein x Gir under climatic influence during the morning and afternoon shifts of the raining season of the year, in southern of Piaui state. This study was carried out at the experimental farm of the Federal University of Piaui (UFPI), Campus Professora Cinobelina Elvas (CPCE), situated in Bom Jesus city, in Piaui state. Ten cows in lactation were used and respiratory and cardiac frequencies, rectal temperature and sweating rate were measured. The physical analysis of the thermal environment of the install was acquired in the weather station of the UFPIs campus, which registered the temperature and air relative humidity. The wet bulb globe temperature index (WBGTI) was obtained by a thermometer inserted into a black globe. There was significant difference (P 0.05) for all the weather variables, highlighting the air temperature, which had higher value in the afternoon shift (30.41 C). A significant effect (P 0.05) was observed for the physiological variables respiratory rate and sweating rate, in which higher values were measured during the afternoon shift, being respectively 51.59 mov./min. and 104.69 g/m/h, probably because this shift showed the highest values for air temperature. The animals evaluated in this study showed a certain level of thermal discomfort, mainly in the afternoon shift.(AU)

O objetivo deste trabalho é avaliar as característicastermorreguladoras de bovinos mestiços Holandês x Gir sobinfluência climática durante os turnos manhã e tarde doperíodo chuvoso do ano, no sul do estado do Piauí. Estetrabalho foi conduzido na fazenda experimental daUniversidade Federal do Piauí (UFPI), Campus ProfessoraCinobelina Elvas (CPCE), localizado na cidade de BomJesus, estado do Piauí. Foram utilizadas dez vacas em lactação e mensuradas as frequências respiratória e cardíaca, temperatura retal e a taxa de sudação. A análise física do ambiente térmico da instalação foi adquirida na estação meteorológica do campus da UFPI, que registrou a temperatura e umidade do ar. O índice de temperatura de globo e umidade (ITGU) foi obtido através de um termômetro inserido em um globo negro. Houve diferença significativa (P<0,05) para todas as variáveis meteorológicas, destacando-se a temperatura do ar, que teve um maior valor no turno da tarde (30,41 °C). Para as variáveis fisiológicas foi observado efeito significativo (P<0,05) para a frequência respiratória e a taxa de sudação nas quais valores maiores destas variáveis foram mensurados no turno da tarde, sendo 51,59 mov./min. e 104,69 g/m/h respectivamente, provavelmente por este turno ter apresentado maiores valores de temperatura do ar. Os animais apresentaram certo nível de desconforto térmico, principalmente no turno da tarde.