RESUMO

The present study aimed to analyze large volumes of tympanic temperature (TT) data to identify its use as a physiological indicator of climatic conditions and its relationship with milk production in grazing cows under tropical lowland conditions. Three dairy farms and 21 multiparous early lactation cows were included in the study. Seven animals were equipped with tympanic temperature wireless sensors within each farm, and permanent information was collected hourly for 22 days on average. Ambient temperature (AT), relative humidity (RH), wind speed (WS), precipitation (PP), and THI information were obtained from meteorological stations located close to each farm. Statistical analyses included Spearman correlations and random coefficient regression models (P < 0.05). TT presented moderate and significant correlations with AT (0.35 to 0.49), SR (0.25 to 0.32), THI (0.35 to 0.49), and RH (-0.35 to -0.49). Climatic variables like AT, PP, SR, and WS were the most contributing factors to TT prediction (R2 =0.42 to 0.86). Grazing dairy cows in tropical scenarios accumulate heat during the day and dissipate it at nighttime, although higher producing animals deal with more problems to reach thermal homeostasis. Correlations between TT and daily milk production varied according to animal yield; however, higher TT values were related to the most productive cows. The effect of TT on milk production prediction was not conclusive among farms, possibly by animal management or others characteristics of the systems. TT determination through remote sensors allows a reliable diagnosis of the physiological temperature response to climatic conditions.(AU)

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RESUMO

This study aimed to evaluate the biophysical responses of Santa Inês ewes and crossbred Santa Inês-Dorper ewes in a hot environment. Physiological parameters were measured: rectal temperature, respiratory rate, coat surface temperature, skin surface temperature, and heart rate. Biophysical parameters were also calculated: heat exchanges by cutaneous convection and radiation, as well as heat storage and thermal conduction in fleece. Throughout the collection period, meteorological variables were similarly monitored. The statistical design was completely randomized in a factorial 2 x 2 (two genotypes and two shifts). According to meteorological variables, the afternoon shift introduced itself with greater heat stress compared with the morning shift. The effect of interaction between genotypes and shifts for respiratory rate, rectal temperature, skin surface temperature, and hair coat surface temperature showed that genotypes exhibit different physiological behavior under similar heat stress situations. Heart rate had the effect of two sources of variation. As for the biophysical parameters, radiation and conduction exchanges in fleece presenting with the shift effect. Heat storage was slightly higher in Santa Inês ewes than in their crossbred Santa Inês-Dorper ewes. It was therefore concluded that crossbred ewes use physiological mechanisms more vigorously to perform heat exchanges, similar to Santa Inês ewes, which have become more adapted to a hot environment. (AU)

Assuntos

RESUMO

This study aimed to evaluate the biophysical responses of Santa Inês ewes and crossbred Santa Inês-Dorper ewes in a hot environment. Physiological parameters were measured: rectal temperature, respiratory rate, coat surface temperature, skin surface temperature, and heart rate. Biophysical parameters were also calculated: heat exchanges by cutaneous convection and radiation, as well as heat storage and thermal conduction in fleece. Throughout the collection period, meteorological variables were similarly monitored. The statistical design was completely randomized in a factorial 2 x 2 (two genotypes and two shifts). According to meteorological variables, the afternoon shift introduced itself with greater heat stress compared with the morning shift. The effect of interaction between genotypes and shifts for respiratory rate, rectal temperature, skin surface temperature, and hair coat surface temperature showed that genotypes exhibit different physiological behavior under similar heat stress situations. Heart rate had the effect of two sources of variation. As for the biophysical parameters, radiation and conduction exchanges in fleece presenting with the shift effect. Heat storage was slightly higher in Santa Inês ewes than in their crossbred Santa Inês-Dorper ewes. It was therefore concluded that crossbred ewes use physiological mechanisms more vigorously to perform heat exchanges, similar to Santa Inês ewes, which have become more adapted to a hot environment.

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RESUMO

In this study we aimed to evaluate the physiological variables of sheep under the influence of Piauí semiarid environment. We used ten Santa Ines rams with black coat. The study was conducted at the small ruminants sector of the Federal University of Piauí, Campus Professora Cinobelina Elvas. Respiratory and cardiac frequencies, rectal temperature and sweating rate were measured.  Temperature, air relative humidity and globe temperature and humidity index were recorded at the Campus weather station. There was a significant difference for all the meteorological variables so that the highest values were observed for the afternoon shift, except for air relative humidity (33.52%). For physiological variables significant effect was observed for respiratory and cardiac frequencies and higher values of these variables were found in the morning shift, with 49,50 breath/min and 89,52 beats/min, respectively. For rectal temperature, significant effect was observed, with the highest values for the afternoon shift (39,92C). We can notice that the animals needed to activate their physiological variables to keep their bodies in thermoneutral zone.(AU)

Objetivou-se com este estudo avaliar as variáveis fisiológicas de ovinos sob influência do ambiente semiárido piauiense. Utilizou-se dez ovinos machos da raça Santa Inês, com pelagem preta. O estudo foi conduzido no setor depequenos ruminantes da Universidade Federal do Piauí, Campus Professora Cinobelina Elvas. Foram mensuradas as frequências respiratória e cardíaca, temperatura retal e a taxa de sudação. Na estação meteorológica do campus foram registradas a temperatura e umidade relativa do ar, além do índice de temperatura de globo e umidade. Pode-se observar que houve diferença significativa para todas as variáveis meteorológicas e com os maiores valores para o turno da tarde, exceto para umidade relativa do ar (33,52%). Para asvariáveis fisiológicas foi observado efeito significativo para as frequências respiratória e cardíaca e que valores maiores destas variáveis foram encontradas no turno da manhã, sendo 49,50 resp/min e 89,52 batimentos/min, respectivamente. Para a temperatura retal, foi observado efeito significativo,com os maiores valores para o turno da tarde (39,92°C). Pode-se verificar que foi necessário para os animais acionarem suas variáveis fisiológicas para manter seu corpo em zona de termoneutralidade.(AU)

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RESUMO

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.

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RESUMO

The aim of this study was to evaluate the physiological responses of Santa Ines and its crossbreeds with Suffolk races and Ile de France in Piracicaba, Brazil. Eighteen ewes were used assigned to a completely randomized design in a factorial diagram (3 x 3, 3 breed group: Santa Inês (SI); ½ Santa Inês + ½ Suffolk (Su x SI), and ½ Santa Inês + ½ Ile de France (Ile x SI) and 3 times of observation: 07:00, 13:00 and 19:00 hours) with 6 repetitions. The ewes were used to evaluate: rectal temperature (RT), superficial temperature (ST), eardrum temperature (ET) and respiratory frequency (RF). The ST showed difference (P 0.05) among genetic groups, being Ile x SI the group that showed the lower mean at 07:00 and the greater at 13:00. For the ET the Santa Inês presented the lower mean (P 0.05) than the others, at 13:00 and 19:00. The group Su x SI was greater RT (P 0.05) than SI. The lowest RT was registered at the morning. There was no difference (P>0.05) between the 13:00 and the 19:00. The crossbreeding Ile x SI show greater heat tolerance than Su x SI.(AU)

Objetivou-se avaliar as respostas fisiológicas da raça Santa Inês e seus mestiços com as raças Suffolk e Ile de France, em Piracicaba, Brasil. Foram utilizadas dezoitoovelhas distribuídas em delineamento experimental inteiramente casualizado no esquema fatorial 3 x 3, sendo 3 grupos raciais: Santa Inês (SI); ½ Santa Inês + ½ Suffolk (Su x SI), ½ Santa Inês + ½ Ile de France (Ile x SI) e 3 horários de observação: 7:00, 13:00 e 19:00 horas, com 6 repetições. Foram estudadas: temperatura retal (TR), temperatura superficial (TS), temperatura timpânica (TT) e frequência respiratória (FR). Os animais do grupo racial Ile x SI apresentaram menor TS às 7:00 horas em relação aos demais grupos raciais (P<0,05), entretanto apresentaram maior TS às 13:00 horas (P<0,05). A TT às 13:00 e 19:00 horas dosanimais da raça Santa Inês foi inferior a dos demais grupos raciais (P<0,05). A TR das ovelhas do cruzamento Su x SI foi superior (P<0,05) a das ovelhas SI, não havendo diferença entre as ovelhas Su x SI e Ile x SI, bem como entre as ovelhas SI e Ile x SI. Para todos os grupos raciais a menor TR foi registrada pela manhã, não havendo diferença entre os horários das 13:00 e 19:00 horas. Os animais ½ Santa Inês + ½ Ile de France apresentam maior tolerância ao calor emrelação aos mestiços ½ Santa Inês + ½ Suffolk.(AU)

Assuntos

RESUMO

In this study we aimed to evaluate the physiological variables of sheep under the influence of Piauí semiarid environment. We used ten Santa Ines rams with black coat. The study was conducted at the small ruminants sector of the Federal University of Piauí, Campus Professora Cinobelina Elvas. Respiratory and cardiac frequencies, rectal temperature and sweating rate were measured.  Temperature, air relative humidity and globe temperature and humidity index were recorded at the Campus weather station. There was a significant difference for all the meteorological variables so that the highest values were observed for the afternoon shift, except for air relative humidity (33.52%). For physiological variables significant effect was observed for respiratory and cardiac frequencies and higher values of these variables were found in the morning shift, with 49,50 breath/min and 89,52 beats/min, respectively. For rectal temperature, significant effect was observed, with the highest values for the afternoon shift (39,92C). We can notice that the animals needed to activate their physiological variables to keep their bodies in thermoneutral zone.

Objetivou-se com este estudo avaliar as variáveis fisiológicas de ovinos sob influência do ambiente semiárido piauiense. Utilizou-se dez ovinos machos da raça Santa Inês, com pelagem preta. O estudo foi conduzido no setor depequenos ruminantes da Universidade Federal do Piauí, Campus Professora Cinobelina Elvas. Foram mensuradas as frequências respiratória e cardíaca, temperatura retal e a taxa de sudação. Na estação meteorológica do campus foram registradas a temperatura e umidade relativa do ar, além do índice de temperatura de globo e umidade. Pode-se observar que houve diferença significativa para todas as variáveis meteorológicas e com os maiores valores para o turno da tarde, exceto para umidade relativa do ar (33,52%). Para asvariáveis fisiológicas foi observado efeito significativo para as frequências respiratória e cardíaca e que valores maiores destas variáveis foram encontradas no turno da manhã, sendo 49,50 resp/min e 89,52 batimentos/min, respectivamente. Para a temperatura retal, foi observado efeito significativo,com os maiores valores para o turno da tarde (39,92°C). Pode-se verificar que foi necessário para os animais acionarem suas variáveis fisiológicas para manter seu corpo em zona de termoneutralidade.

Assuntos

RESUMO

The aim of this study was to evaluate the physiological responses of Santa Ines and its crossbreeds with Suffolk races and Ile de France in Piracicaba, Brazil. Eighteen ewes were used assigned to a completely randomized design in a factorial diagram (3 x 3, 3 breed group: Santa Inês (SI); ½ Santa Inês + ½ Suffolk (Su x SI), and ½ Santa Inês + ½ Ile de France (Ile x SI) and 3 times of observation: 07:00, 13:00 and 19:00 hours) with 6 repetitions. The ewes were used to evaluate: rectal temperature (RT), superficial temperature (ST), eardrum temperature (ET) and respiratory frequency (RF). The ST showed difference (P 0.05) among genetic groups, being Ile x SI the group that showed the lower mean at 07:00 and the greater at 13:00. For the ET the Santa Inês presented the lower mean (P 0.05) than the others, at 13:00 and 19:00. The group Su x SI was greater RT (P 0.05) than SI. The lowest RT was registered at the morning. There was no difference (P>0.05) between the 13:00 and the 19:00. The crossbreeding Ile x SI show greater heat tolerance than Su x SI.

Objetivou-se avaliar as respostas fisiológicas da raça Santa Inês e seus mestiços com as raças Suffolk e Ile de France, em Piracicaba, Brasil. Foram utilizadas dezoitoovelhas distribuídas em delineamento experimental inteiramente casualizado no esquema fatorial 3 x 3, sendo 3 grupos raciais: Santa Inês (SI); ½ Santa Inês + ½ Suffolk (Su x SI), ½ Santa Inês + ½ Ile de France (Ile x SI) e 3 horários de observação: 7:00, 13:00 e 19:00 horas, com 6 repetições. Foram estudadas: temperatura retal (TR), temperatura superficial (TS), temperatura timpânica (TT) e frequência respiratória (FR). Os animais do grupo racial Ile x SI apresentaram menor TS às 7:00 horas em relação aos demais grupos raciais (P<0,05), entretanto apresentaram maior TS às 13:00 horas (P<0,05). A TT às 13:00 e 19:00 horas dosanimais da raça Santa Inês foi inferior a dos demais grupos raciais (P<0,05). A TR das ovelhas do cruzamento Su x SI foi superior (P<0,05) a das ovelhas SI, não havendo diferença entre as ovelhas Su x SI e Ile x SI, bem como entre as ovelhas SI e Ile x SI. Para todos os grupos raciais a menor TR foi registrada pela manhã, não havendo diferença entre os horários das 13:00 e 19:00 horas. Os animais ½ Santa Inês + ½ Ile de France apresentam maior tolerância ao calor emrelação aos mestiços ½ Santa Inês + ½ Suffolk.

Assuntos

RESUMO

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.

Assuntos

RESUMO

In this study, a comprehensive investigation on the temperature increase at the light guide tip of several commercial light-emitting diode (LED) light-curing units (LCUs) and the associated thermal variation (ΔT) at the pulpal floor of dental cavities was carried out. In total, 15 LEDs from all generations were investigated, testing a quartz-tungsten-halogen (QTH) unit as a reference. The irradiance level was measured with a power meter, and spectral distribution was analyzed using a spectrometer. Temperature increase at the tip was measured with a type-K thermocouple connected to a thermometer, while ΔT at the pulpal floor was measured by an infrared photodetector in class V cavities, with a 1-mm-thick dentin pulpal floor. The relationship among measured irradiance, ΔT at the tip, and ΔT at the pulpal floor was investigated using regression analyses. Large discrepancies between the expected and measured irradiances were detected for some LCUs. Most of the LCUs showed an emission spectrum narrower than the QTH unit, with emission peaks usually between 450 and 470 nm. The temperature increase at the tip followed a logarithmic growth for LCUs with irradiance ≥1000 mW/cm(2), with ΔT at the tip following the measured irradiance linearly (R(2)=0.67). Linear temperature increase at the pulpal floor over the 40-second exposure time was observed for several LCUs, with linear association between ΔT at the pulpal floor and measured irradiance (R(2)=0.39) or ΔT at the tip (R(2)=0.28). In conclusion, contemporary LED units show varied irradiance levels that affect the temperature increase at the light guide tip and, as a consequence, the thermal variation at the pulpal floor of dental cavities.

Assuntos