Physiological responses, water consumption, and feeding behaviour of lamb breeds fed diets containing different proportions of concentrate

The use of adapted breeds, such as Santa Inês, is of paramount importance for regions with high temperatures because they develop efficient mechanisms for heat dissipation. Furthermore, some breeds have physiological adaptations, such as more efficient mechanisms for the digestion of fibrous foods (e.g. Rabo Largo), which can reduce the harmful effects of semiarid environments. We studied the ingestive behaviour, water consumption, and physiological parameters during feeding of two native sheep breeds fed diets containing high (700 g/kg DM; HC diet) or low (300 g/kg DM; LC diet) percentages of concentrates, based on dry matter (DM). A total of 40 uncastrated male lambs (20 Rabo Largo [breed 1] and 20 Santa Inês [breed 2], with an average body weight of 16.68 ± 2.78 kg, and 19.29 kg ± 3.28 kg, respectively), were distributed in a randomised block design in a two-by-two factorial scheme (breeds × diets) with 10 repetitions. Santa Inês lambs consumed and ruminated DM (P = 0.029 for both) and neutral detergent fibre (NDF; P = 0.001 and P = 0.004, respectively) more efficiently than RaboLargo lambs, while the latter showed an increase in respiratory rate (+19 breaths/min) and rectal temperature (+1.3 °C) compared to the Santa Inês lambs (P = 0.001). The HC diet negatively affected (P < 0.05) the feeding behaviour of the animals, reflecting the higher (P < 0.05) water consumption. The results showed that diets rich in concentrate negatively affected the thermoregulation of lambs. Santa Inês have greater feed and thermoregulatory efficiency than Rabo Largo lambs under conditions of heat stress in the feedlot.(AU)

Physiological responses, water consumption, and feeding behaviour of lamb breeds fed diets containing different proportions of concentrate

The use of adapted breeds, such as Santa Inês, is of paramount importance for regions with high temperatures because they develop efficient mechanisms for heat dissipation. Furthermore, some breeds have physiological adaptations, such as more efficient mechanisms for the digestion of fibrous foods (e.g. Rabo Largo), which can reduce the harmful effects of semiarid environments. We studied the ingestive behaviour, water consumption, and physiological parameters during feeding of two native sheep breeds fed diets containing high (700 g/kg DM; HC diet) or low (300 g/kg DM; LC diet) percentages of concentrates, based on dry matter (DM). A total of 40 uncastrated male lambs (20 Rabo Largo [breed 1] and 20 Santa Inês [breed 2], with an average body weight of 16.68 ± 2.78 kg, and 19.29 kg ± 3.28 kg, respectively), were distributed in a randomised block design in a two-by-two factorial scheme (breeds × diets) with 10 repetitions. Santa Inês lambs consumed and ruminated DM (P = 0.029 for both) and neutral detergent fibre (NDF; P = 0.001 and P = 0.004, respectively) more efficiently than RaboLargo lambs, while the latter showed an increase in respiratory rate (+19 breaths/min) and rectal temperature (+1.3 °C) compared to the Santa Inês lambs (P = 0.001). The HC diet negatively affected (P < 0.05) the feeding behaviour of the animals, reflecting the higher (P < 0.05) water consumption. The results showed that diets rich in concentrate negatively affected the thermoregulation of lambs. Santa Inês have greater feed and thermoregulatory efficiency than Rabo Largo lambs under conditions of heat stress in the feedlot.

Simple physiological indicators of ½ Santa Inês × ½ Dorper crossbred sheep raised in the municipality of Mirador, Maranhão, Brazil / Indicadores fisiológicos simples de ovinos mestiços 1/2 Santa Inês X 1/2 Dorper criados no município de Mirador, Maranhão, Brasil

In this study we aimed to evaluate the influence of environmental differences caused by day shifts on the physiological indicators of crossbred ½ Santa Inês × ½ Dorper sheep raised in a semi-intensive system. For this, 12 animals with an average weight of 35.00 ± 5.00 kg were allocated in a completely randomized design, with two treatments (morning shift and afternoon shift) and six replicates per treatment. The environmental variables (temperature (ºC) and relative humidity (%)) were collected using a digital thermo-hygrometer. The black globe temperature and humidity index was calculated using temperature values of the black globe thermometer and dew point. The following physiological indicators were measured in the animals: respiratory rate (mov/min); heart rate (beats/min); rectal temperature (ºC); and surface temperature (ºC). In the morning shift, the average values of air temperature and relative humidity were 31.71ºC and 88.66%, respectively. In the afternoon, the average air temperature was 33.91ºC, while the relative humidity was 62.66%. The highest mean globe temperature and humidity index was observed in the afternoon shift (87.75). The physiological indicators showed the highest mean values in the afternoon shift: respiratory rate 73.72 mov/min; heart rate 81.27 beats/min; rectal temperature 39.98ºC; surface temperature 34.76ºC. The crossbred ½ Santa Inês × ½ Dorper sheep reared in a semi-intensive system showed signs of thermal discomfort.

Objetivou-se com esta pesquisa avaliar a influência das diferenças ambientais proporcionadas pelos turnos do dia sobre os indicadores fisiológicos de ovinos mestiços ½Santa Inês × ½Dorper criados em sistema semi-intensivo. Para isso, foram utilizados 12 animais, com peso médio de 35,00 ± 5,00 Kg, alocados em delineamento inteiramente casualizado, com dois tratamentos (turno manhã e turno tarde) e seis repetições por tratamento. As variáveis ambientais, temperatura (ºC) e umidade relativa do ar (%), foram coletadas com o uso de um termo-higrômetro digital. O índice de temperatura de globo negro e umidade foi calculado usando os valores da temperatura do termômetro de globo negro e do ponto de orvalho. Os indicadores fisiológicos mensurados nos animais foram às frequências, respiratória (mov./min.) e cardíaca (bat./min.), a temperatura retal (ºC) e a temperatura superficial (ºC). As médias para temperatura do ar foram, respectivamente, 31,71ºC e 33,91ºC para os turnos manhã e tarde, enquanto que a umidade relativa do ar foi de 88,66% e 62,66%, nessa mesma ordem. A média para o índice de temperatura de globo e umidade foi superior no turno tarde, com valor igual a 87,75. Os indicadores fisiológicos apresentaram maiores médias para o turno tarde, apresentando valores de 73,72 mov./min., 81,27 bat./min., 39,98ºC e 34,76ºC para frequência respiratória, frequência cardíaca, temperatura retal e temperatura superficial, respectivamente. Os ovinos mestiços ½Santa Inês x ½Dorper criados em sistema semi-intensivo apresentaram sinais de desconforto término.

Efeitos da tosquia no conforto térmico e desempenho produtivo de coelhos (Oryctolagus cuniculus f. domesticus) / Effects of shearing on thermal comfort and productive performance of rabbits (Oryctolagus cuniculus f. domesticus) / Efectos de la esquila sobre el confort térmico y el rendimiento productivo de conejos (Oryctolagus cuniculus f. domesticus

O coelho é uma das espécies mais sensíveis às condições do meio que vivem, sendo a temperatura e umidade os fatores que mais têm influência no seu ambiente. O objetivo com este trabalho foi avaliar a tosquia como alternativa para melhorar o conforto térmico e o desempenho produtivo de coelhos criados de forma intensiva em uma região de clima semiárido. Foram utilizados 26 coelhos mestiços, sadios e em fase de engorda, sendo divididos em gaiolas individuais em dois grupos: treze animais submetidos a tosquia (G1) e treze sem tosquia (G2). O conforto térmico foi avaliado todos os dias pelo cálculo de Índice de Temperatura e Umidade (ITH) e pela análise e comparação dos parâmetros: frequência respiratória (FR), temperatura retal (TR) e temperaturasuperficial (TS). A temperatura e umidade do ambiente foram verificadas em todos os dias do experimento, às 6:00, 9:00, 12:00, 15:00 e 18:00 horas, com um termo-higrômetro. O desempenho dos animais foi avaliado pela pesagem nos dias 0, 10, 20 e 30 do experimento. Como resultado, a FR e TS apresentaram diferença estatística (P<0,05), o grupo dos animais tosquiados apresentou média inferior de FR (221,6 ± 15,4) em relação aos não tosquiados (240,2 ± 26,1). Em relação à TS, houve menores temperaturas nos animais tosquiados (33,8°C ± 0,3) quando comparados com os não tosquiados (35,0°C ± 0,2). Quanto à TR, ficou próximo de 39,5 ºC, inferindo assim que os mecanismos de regulação térmica interno dos animais conseguiram manter a homeotermia desejada. O ganho de peso obteve média de 771,4 gramas no grupo dos animais tosquiados, e 705,2 gramas no grupo dos não tosquiados. Em relação à TR e desempenho dos animais, não foram observadas diferenças estatísticas (P > 0,05). De acordo com os dados obtidos, conclui-se que atosquia pode ser um meio de melhorar o conforto térmico de coelhos.(AU)

The rabbit is one of the most sensitive species to the conditions of the environment in which they live, with temperature and humidity being the factors that most influence their environment. The objective of this work was to evaluate shearing as an alternative to improve the thermal comfort and productive performance of rabbits raised intensively in a region with a semi-arid climate. Twenty-six mixed, healthy and fattening stage rabbits were used and divided into individual cages into two groups: thirteen animals submitted to shearing (G1) and thirteen without shearing (G2). Thermal comfort was evaluated every day by calculating the Temperature and Humidity Index (THI) and by analyzing and comparing the parameters: respiratory rate (RR), rectal temperature (RT) and superficial temperature (ST). The temperature and humidity of the environment were checked every day of the experiment, at 6:00, 9:00, 12:00, 15:00 and 18:00 hours, with a thermo-hygrometer. The performance of the animals was evaluated by weighingon 0, 10, 20 and 30 days of the experiment. As a result, the RR and ST showed a statistical difference (P<0.05), the group of sheared animals had a lower mean of RR (221.6 ± 15.4) in relation to the no sheared animals (240.2 ± 26.1). Regarding the ST, there were lower temperatures in the sheared animals (33.8°C ± 0.3) when compared to the no sheared animals (35.0°C ± 0.2). As for the RT was close to 39.5 ºC, inferring that the thermal regulation mechanisms of the animals managed to maintain the desired homeothermia. Weight gain averaged 771.4 grams in the sheared group, and 705.2 grams in the no sheared group. Regarding the RT and performance of the animals, no statistical differences were observed (P>0.05). According to the data obtained, it is concluded that shearing can improve the thermal comfort of rabbits.(AU)

El conejo es una de las especies más sensibles a las condiciones del medio en el que vive, siendo la temperatura y la humedad los factores que más influyen en su entorno. El objetivo de este trabajo fue evaluar la esquila como alternativapara mejorar el confort térmico y el desempeño productivo de conejos criados de forma intensiva en una región de clima semiárido. Se utilizaron 26 conejos mestizos, sanos y en fase de engorde, divididos en jaulas individuales en dos grupos: trece animalessometidos a esquila (G1) y trece sin esquila (G2). El confort térmico se evaluó diariamente mediante el cálculo del Índice de Temperatura y Humedad (ITH) y mediante el análisis y comparación de los parámetros: frecuencia respiratória (FR), temperatura rectal (TR) y temperatura superficial (TS). La temperatura y humedad del ambiente se verificado todos los días del experimento, a las 6:00, 9:00, 12:00, 15:00 y 18:00 horas, con un termohigrómetro. El rendimiento de los animales se evaluó mediante pesaje los días 0, 10, 20 y 30 del experimento. Como resultado, el FR y el TS mostraron diferencia estadística (P<0,05), el grupo de animales esquilados tuvo una media de FR más baja (221,6 ± 15,4) en relación a los animales no esquilados (240,2 ± 26,1). En cuanto a la TS, hubo temperaturas más bajas en los animales esquilados (33,8 °C ± 0,3) en comparación con los animales no esquilados (35,0 °C ± 0,2). En cuanto a la TR, fue cercana a los 39,5 ºC, infiriendo que los mecanismos internos de regulación térmica de los animales lograron mantener la homeotermia deseada. El aumento de peso promedió 771,4 gramos en el grupo esquilado y 705,2 gramos en el grupo no esquilado. En cuanto al TR y rendimiento de los animales, no se observaron diferencias estadísticas (P > 0,05). De acuerdo con los datos obtenidos, se concluye que las esquila puede ser un medio para mejorar el confort térmico de los conejos.(AU)

Effect of wetting method on the broiler transport in Brazilian Northeast

The aim of this study was to evaluate the efficiency of the load wetting method to attenuate the ambience of the load the transport of broilers. Fourteen commercial consignments were monitored over a 25 km route, and in seven of these, the load wetting was carried (LW) out while in the other seven no wetting was done (LD). The temperatures of the side, top and rear load boxes were analyzed by infrared thermography. The central row load boxes were evaluated by geostatistics, using temperature variability (TA), relative humidity (RH) and the enthalpy comfort index (ECI). The mean was compared by Student's t-test (P < 0.05). The results showed that load wetting has a momentary effect (P < 0.05). The boxes located in the central rows in the LW showed a higher (P < 0.05) ECI compared to those in the LD. Inaddition, areas classified as lethal were formed in the LW. In conclusion, load wetting was not an efficient method to attenuate the ambience of load during the commercial transport of broilers, as it only has momentary and transient effects.(AU)

Effect of wetting method on the broiler transport in Brazilian Northeast

The aim of this study was to evaluate the efficiency of the load wetting method to attenuate the ambience of the load the transport of broilers. Fourteen commercial consignments were monitored over a 25 km route, and in seven of these, the load wetting was carried (LW) out while in the other seven no wetting was done (LD). The temperatures of the side, top and rear load boxes were analyzed by infrared thermography. The central row load boxes were evaluated by geostatistics, using temperature variability (TA), relative humidity (RH) and the enthalpy comfort index (ECI). The mean was compared by Student's t-test (P < 0.05). The results showed that load wetting has a momentary effect (P < 0.05). The boxes located in the central rows in the LW showed a higher (P < 0.05) ECI compared to those in the LD. Inaddition, areas classified as lethal were formed in the LW. In conclusion, load wetting was not an efficient method to attenuate the ambience of load during the commercial transport of broilers, as it only has momentary and transient effects.

Behavior of buffalo heifers reared in shaded and unshaded pastures during the dry season on Marajó Island, Pará, Brazil

The objective of this research was to evaluate the behavior of twenty buffalo heifers reared during the dry season on Marajó Island, Pará, Brazil. The animals were distributed into two groups, those with shade (WS) and those without shade (WOS). The experimental day was divided into six shifts: morning (6:00 to 9:55 a.m.), intermediate (10:00 a.m. to 1:55 p.m.), afternoon (2:00 to 5:55 p.m.), evening (6:00 to 9:55 p.m.), night (10:00 p.m. to 1:55 a.m.), and early morning (2:00 to 5:55 a.m.). The WS group was kept in silvipastoral system paddocks, while the WOS group was kept in unshaded paddocks. Climatic data were registered and temperature and humidity index (THI) were calculated. Behavior data such as grazing, rumination, idle time, and other activities (walking, defecating, mounting, drinking water, urinating, eating salt) were evaluated. The results showed that the THI was higher in the WOS group. Grazing time was higher in the WOS group than in the WS group in the intermediate shift (p < 0.05), while in the afternoon, evening, and early morning shifts, the WS group spent more time grazing than the WOS group. In the intermediate and early morning shifts, the WS group spent more time ruminating (p < 0.05); the WS group ruminated more than the WOS group. The WOS group had more idle time, especially in the evening and early morning shifts (p < 0.05), while the WS group had more idle time in the intermediate shift (p < 0.05). We conclude that buffaloes graze and ruminate more intensely when they are reared in a shaded system on the island of Marajó.(AU)

Behavior of buffalo heifers reared in shaded and unshaded pastures during the dry season on Marajó Island, Pará, Brazil

The objective of this research was to evaluate the behavior of twenty buffalo heifers reared during the dry season on Marajó Island, Pará, Brazil. The animals were distributed into two groups, those with shade (WS) and those without shade (WOS). The experimental day was divided into six shifts: morning (6:00 to 9:55 a.m.), intermediate (10:00 a.m. to 1:55 p.m.), afternoon (2:00 to 5:55 p.m.), evening (6:00 to 9:55 p.m.), night (10:00 p.m. to 1:55 a.m.), and early morning (2:00 to 5:55 a.m.). The WS group was kept in silvipastoral system paddocks, while the WOS group was kept in unshaded paddocks. Climatic data were registered and temperature and humidity index (THI) were calculated. Behavior data such as grazing, rumination, idle time, and other activities (walking, defecating, mounting, drinking water, urinating, eating salt) were evaluated. The results showed that the THI was higher in the WOS group. Grazing time was higher in the WOS group than in the WS group in the intermediate shift (p < 0.05), while in the afternoon, evening, and early morning shifts, the WS group spent more time grazing than the WOS group. In the intermediate and early morning shifts, the WS group spent more time ruminating (p < 0.05); the WS group ruminated more than the WOS group. The WOS group had more idle time, especially in the evening and early morning shifts (p < 0.05), while the WS group had more idle time in the intermediate shift (p < 0.05). We conclude that buffaloes graze and ruminate more intensely when they are reared in a shaded system on the island of Marajó.

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.

Physiological responses and animal behavior in Bonsmara-Hereford crosses vs. Hereford purebred on environment stress

ABSTRACT: Adaptative traits (rectal temperature-RT, respiratory rate-RR) and grazing behavior (Grazing, Ruminating and Rest time, and Sun or Shade time) of Bonsmara-Hereford crossbred-BH, n = 15, and purebred Hereford-HH, n = 18, yearling heifers, in a grazing system of Uruguay. Environment characterization was made using THIadjusted by radiation and wind speed (no, mild, and severe heat weaves), and the comprehensive climatic index-CCI (no, middle, moderate and severe stress). Adaptative traits were measured twice a day, weekly, in two consecutive days in summer and winter at 08h00 and 16h00. Grazing behavior was observed from 07h00 to 21h00 each 600 s twice in summer. The records were analyzed using a mixed model. Significant effect of genotype was observed in mild heat waves for RR and RT in the afternoon (BH lower than HH). For CCI in a.m., the RR was lower than HH in BH in severe stress, while in p.m., the RR was lower in all of CCI levels. RT in p.m. in moderate and severe was lower in BH than in HH. In winter, no differences were found. In grazing behavior, HH rests longer than BH doe; also, HH spends more time in the shade (34 %) than BH does (22 %). BH genotype showed better thermoregulation and grazing behavior at higher temperatures compared to HH.

Physiological responses and animal behavior in Bonsmara-Hereford crosses vs. Hereford purebred on environment stress

Adaptative traits (rectal temperature-RT, respiratory rate-RR) and grazing behavior (Grazing, Ruminating and Rest time, and Sun or Shade time) of Bonsmara-Hereford crossbred-BH, n = 15, and purebred Hereford-HH, n = 18, yearling heifers, in a grazing system of Uruguay. Environment characterization was made using THIadjusted by radiation and wind speed (no, mild, and severe heat weaves), and the comprehensive climatic index-CCI (no, middle, moderate and severe stress). Adaptative traits were measured twice a day, weekly, in two consecutive days in summer and winter at 08h00 and 16h00. Grazing behavior was observed from 07h00 to 21h00 each 600 s twice in summer. The records were analyzed using a mixed model. Significant effect of genotype was observed in mild heat waves for RR and RT in the afternoon (BH lower than HH). For CCI in a.m., the RR was lower than HH in BH in severe stress, while in p.m., the RR was lower in all of CCI levels. RT in p.m. in moderate and severe was lower in BH than in HH. In winter, no differences were found. In grazing behavior, HH rests longer than BH doe; also, HH spends more time in the shade (34 %) than BH does (22 %). BH genotype showed better thermoregulation and grazing behavior at higher temperatures compared to HH.(AU)

Physiological responses and animal behavior in Bonsmara-Hereford crosses vs. Hereford purebred on environment stress

ABSTRACT: Adaptative traits (rectal temperature-RT, respiratory rate-RR) and grazing behavior (Grazing, Ruminating and Rest time, and Sun or Shade time) of Bonsmara-Hereford crossbred-BH, n = 15, and purebred Hereford-HH, n = 18, yearling heifers, in a grazing system of Uruguay. Environment characterization was made using THIadjusted by radiation and wind speed (no, mild, and severe heat weaves), and the comprehensive climatic index-CCI (no, middle, moderate and severe stress). Adaptative traits were measured twice a day, weekly, in two consecutive days in summer and winter at 08h00 and 16h00. Grazing behavior was observed from 07h00 to 21h00 each 600 s twice in summer. The records were analyzed using a mixed model. Significant effect of genotype was observed in mild heat waves for RR and RT in the afternoon (BH lower than HH). For CCI in a.m., the RR was lower than HH in BH in severe stress, while in p.m., the RR was lower in all of CCI levels. RT in p.m. in moderate and severe was lower in BH than in HH. In winter, no differences were found. In grazing behavior, HH rests longer than BH doe; also, HH spends more time in the shade (34 %) than BH does (22 %). BH genotype showed better thermoregulation and grazing behavior at higher temperatures compared to HH.

Thermal conditioning in the broiler production: challenges and possibilities

With the introduction of new technologies that lead to the development of new systems of poultry breeding, have been promoted to the animals better thermal comfort conditions. This lessens the great challenge for industrial poultry, with regard to aviary constructions, resulting in increased productivity. It is known that an animal in heat stress condition presents lower productive performance. A lower feed conversion caused by decreased feed intake is the main cause. Multidisciplinary studies have been developed seeking the deepening the needs and possibilities already available about these new systems. With this, this review seeks to approach in a didactic and simplified way the planning and construction of aviary sheds aiming to provide an suitable thermal conditioning for broiler accommodation.(AU)

Thermal conditioning in the broiler production: challenges and possibilities

With the introduction of new technologies that lead to the development of new systems of poultry breeding, have been promoted to the animals better thermal comfort conditions. This lessens the great challenge for industrial poultry, with regard to aviary constructions, resulting in increased productivity. It is known that an animal in heat stress condition presents lower productive performance. A lower feed conversion caused by decreased feed intake is the main cause. Multidisciplinary studies have been developed seeking the deepening the needs and possibilities already available about these new systems. With this, this review seeks to approach in a didactic and simplified way the planning and construction of aviary sheds aiming to provide an suitable thermal conditioning for broiler accommodation.

Assessment of indices of thermal stress indicators among male buffaloes reared in the Eastern Brazilian Amazon / Variáveis de clima e fisiologia para explicar índices indicadores de estresse térmico de búfalos criados na Amazônia Oriental

This research aimed to determine the most appropriate thermal comfort index for buffaloesreared in the Eastern Amazon, Pará, Brazil. Twenty male Murrah buffaloes were used, and data on climatevariables, rectal temperature (RT), body surface temperature (BST), and respiratory rate (RR) wererecorded. Subsequently, the following indices were calculated: Temperature and Humidity Index (THI),Global Temperature and Humidity Index (GTHI), Benezras Thermal Comfort Index (BTCI), IbériasHeat Tolerance Index (IHTI), the general, effective, and practical Buffalo Comfort Climatic ConditionsIndices (BCCCIg, BCCCIe, and BCCCIp, respectively) and the general, effective, and practical BuffaloEnvironmental Comfort Indices (BECIg, BECIe, and BECIp, respectively) in the morning and afternoon.Higher values for THI, GTHI, RT, BST, RR, BTCI, BCCCIg, BCCCIe, BCCCIp, BECIg, BECIe, andBECIp were observed in the afternoon, and the highest IHTI values were found in the morning. A positivecorrelation was found among the physiological variables and THI, GTHI, BTCI, BCCCIg, BECIg,BCCCIe, BECIe, BCCCIp, BECIp, while a negative correlation was found for RT and BST with IHTI. Theindices THI, GTHI, BCCCIg, BECIg, BCCCIe, BECIe, BCCCIp, and BECIp were determined to be veryefficient to assess the thermal comfort status of buffaloes under the conditions of the present research.(AU)

A pesquisa objetivou determinar o índice de conforto térmico mais adequado para búfaloscriados na Amazônia Oriental, Pará, Brasil. Foram utilizados vinte búfalos Murrah. Foram registradosdados de variáveis climáticas e temperatura retal (TR), temperatura da superfície corporal (TSC) efrequência respiratória (FR), e foram calculados os índices: Índice de Temperatura e Umidade (ITU),Índice de Temperatura de Globo e Umidade (ITGU), Índice de Conforto Térmico de Benezra (ICB),Índice de Tolerância ao Calor de Ibéria (ITCI), Índice de Condições Climáticas de Conforto para búfalosgeral (BCCCIg), efetivo (BCCCIe) e prático (BCCCIp) e Índice de Conforto Ambiental para búfalos geral(BECIg), efetivo (BECIe) e prático (BECIp), nos períodos da manhã e da tarde. Foram observados valoresde ITU, ITGU, TR, TSC, FR, ICB, BCCCIg, BCCCIe, BCCCIp, BECIg, BECIe e BECIp mais elevados à tarde. Os maiores valores de ITCI foram encontrados de manhã. Houve correlação positiva entre as variáveis fisiológicas e ITU, ITGU, ITCI, BCCCIg, BECIg, BCCCIe, BECIg, BCCCIe, BECIp, enquanto uma correlação negativa foi encontrada para TR e TSC com ITCI. Os índices THI, GTHI, BCCCIg, BECIg, BCCCIe, BECIe, BCCCIp e BECIp são eficientes para avaliar o estado de conforto térmico dos búfalos na Amazônia Oriental.(AU)

Assessment of indices of thermal stress indicators among male buffaloes reared in the Eastern Brazilian Amazon / Variáveis de clima e fisiologia para explicar índices indicadores de estresse térmico de búfalos criados na Amazônia Oriental

This research aimed to determine the most appropriate thermal comfort index for buffaloesreared in the Eastern Amazon, Pará, Brazil. Twenty male Murrah buffaloes were used, and data on climatevariables, rectal temperature (RT), body surface temperature (BST), and respiratory rate (RR) wererecorded. Subsequently, the following indices were calculated: Temperature and Humidity Index (THI),Global Temperature and Humidity Index (GTHI), Benezra’s Thermal Comfort Index (BTCI), Ibéria’sHeat Tolerance Index (IHTI), the general, effective, and practical Buffalo Comfort Climatic ConditionsIndices (BCCCIg, BCCCIe, and BCCCIp, respectively) and the general, effective, and practical BuffaloEnvironmental Comfort Indices (BECIg, BECIe, and BECIp, respectively) in the morning and afternoon.Higher values for THI, GTHI, RT, BST, RR, BTCI, BCCCIg, BCCCIe, BCCCIp, BECIg, BECIe, andBECIp were observed in the afternoon, and the highest IHTI values were found in the morning. A positivecorrelation was found among the physiological variables and THI, GTHI, BTCI, BCCCIg, BECIg,BCCCIe, BECIe, BCCCIp, BECIp, while a negative correlation was found for RT and BST with IHTI. Theindices THI, GTHI, BCCCIg, BECIg, BCCCIe, BECIe, BCCCIp, and BECIp were determined to be veryefficient to assess the thermal comfort status of buffaloes under the conditions of the present research.

A pesquisa objetivou determinar o índice de conforto térmico mais adequado para búfaloscriados na Amazônia Oriental, Pará, Brasil. Foram utilizados vinte búfalos Murrah. Foram registradosdados de variáveis climáticas e temperatura retal (TR), temperatura da superfície corporal (TSC) efrequência respiratória (FR), e foram calculados os índices: Índice de Temperatura e Umidade (ITU),Índice de Temperatura de Globo e Umidade (ITGU), Índice de Conforto Térmico de Benezra (ICB),Índice de Tolerância ao Calor de Ibéria (ITCI), Índice de Condições Climáticas de Conforto para búfalosgeral (BCCCIg), efetivo (BCCCIe) e prático (BCCCIp) e Índice de Conforto Ambiental para búfalos geral(BECIg), efetivo (BECIe) e prático (BECIp), nos períodos da manhã e da tarde. Foram observados valoresde ITU, ITGU, TR, TSC, FR, ICB, BCCCIg, BCCCIe, BCCCIp, BECIg, BECIe e BECIp mais elevados à tarde. Os maiores valores de ITCI foram encontrados de manhã. Houve correlação positiva entre as variáveis fisiológicas e ITU, ITGU, ITCI, BCCCIg, BECIg, BCCCIe, BECIg, BCCCIe, BECIp, enquanto uma correlação negativa foi encontrada para TR e TSC com ITCI. Os índices THI, GTHI, BCCCIg, BECIg, BCCCIe, BECIe, BCCCIp e BECIp são eficientes para avaliar o estado de conforto térmico dos búfalos na Amazônia Oriental.

Productive and reproductive performance, behavior and physiology of cattle under heat stress conditions

This review aimed to detail the main information pertinent to the physiological and behavioral mechanisms evidenced in cattle under heat stress conditions. Brazilian cattle-breeding represents the second largest herd in the world, promoting great impact on the country's exports. Throughout their adaptability, these animals were submitted to different environments, which directly influence productive and reproductive performance, seeking compensatory mechanisms to maintain body homeostasis. Therefore, we can consider that heat stress directly affects the physiological and behavioral responses of cattle subjected to high temperatures. Adaptability of breeds to tropics should be considered of extreme importance in the choice of a productive activity for cattle-breeding and, particularly, in hot environments.(AU)

Thermal comfort indexes and physiological parameters of Santa Inês and crossbreed ewes in the semi-arid

The objective of this study was evaluated the thermal comfort indexes and physiological parameters in Santa Inês and crossbreed ewes in Brazilian semiarid. The research was developed at experimental station Benjamin Maranhão, twenty non pregnant female sheep were used, 10 pure and 10 crossbreed (½ Dorper + ½ Santa Inês), averaging 26.7 ± 2.1 kg and with 150 days of age at the beginning of the study and confined in a covered sheepfold. A completely randomized design in a 2 x 2 factorial scheme (two genotypes and two shifts) with four treatments and five repetitions was used. The interior and exterior thermal comfort indexes were, most of the day, above the thermal comfort zone for sheep. The rectal temperature, superficial temperature, respiratory rate and cardiac rate was more elevated in the afternoon, and the Santa Inês animals showed in the mornings low rectal temperature values, as well as superficial temperature, respiratory and cardiac rate when compared to the crossbreed.(AU)

Growth and reproduction hormones of ruminants subjected to heat stress

The adaptation of the animals, either temperate or tropical climate, is mainly related to physiology and its adaptation to the environment. When subjected to temperature and humidity different from the usual air, these animals found in heat stress difficulty reproduction and production. The endocrine system is one of those responsible for controlling the stress response, and rapid and appropriate growth is one of the elements of greatest economic importance toward meat production, and more producers want to improve, to accelerate the production rate and decreasing production costs. Thus, the aim of this review was to evaluate, through research papers found in the literature, the influence of heat stress on the hormones of growth and reproduction in ruminants. It was observed that even in studies that do not consider the productive performance of the animals, the influence of these parameters is significant in the ambience and the degree of adaptation of the same. However, more research should be conducted in order to evaluate the production of animals of different species under the conditions of different regions, as well as search for alternatives to achieve the best animal production levels, either by finding the best way of introducing exotic breeds, or the possibility of bringing more comfort to the animals in their various productive and reproductive stages.(AU)