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Simple Summary: The objective of this work was to evaluate the effects of climatic conditions and supplementation based on palm kernel cake, on the thermoregulation of crossbred buffaloes in the eastern Amazon. Over a 12-month period, 24 female buffaloes with an initial age of 54 ± 7 months and an average weight of 503.1 ± 23 kg were divided into four groups with different levels of palm kernel cake supplementation relative to body weight. The animals were kept in Brachiaria brizantha pastures with access to water and mineral salt. Supplementation did not influence the physiological variables of thermoregulation. Throughout the year, mean values of rectal temperature, respiratory rate and body surface temperature were higher in the afternoon (p > 0.05). Supplementation with palm cake did not result in influences on the thermoregulation of buffaloes in the study region. The respiratory rate showed an association with the annual seasonality of temperatures, with higher averages in the afternoons of the rainy season. The positive correlation between the rectal temperature, respiratory rate, and body surface temperature indicates that buffaloes respond to atmospheric thermal elevations (afternoon period), which is reflected in increasing thermal indices. In ruminants, diet composition has a positive correlation with heat production, which can influence thermoregulation, energy expenditure and, consequently, animal performance. The objective of this work was to evaluate the effects of climatic conditions and supplementation based on palm kernel cake, on the thermoregulation of crossbred buffaloes in the eastern Amazon. The research was carried out at Embrapa Amazônia Oriental (01°26′ S and 48°24′ W), Belém, Pará, and lasted 12 months (representing the entire year). Twenty-four buffaloes, females, with initial age and an average weight of 54 ± 7 months and 503.1 ± 23 kg, respectively, non-pregnant, non-lactating and clinically healthy were used, divided into four treatments based on the supplementation content of the palm cake (%DM) in relation to their body weight (%): 0, 0.25, 0.50 and 1.0. The animals were kept in paddocks with Brachiaria brizantha (cv. Marandu), in a rotating system, with water to drink and mineral salt ad libitum. Equipment was installed to record environmental data (temperature and relative humidity, dew point temperature, wet bulb and black globe) and physiological data: rectal temperature (RT); respiratory rate (RR); and body surface temperature (BST), recorded twice a day, always in the morning (6:00 a.m. to 7:00 a.m.) and afternoon (12:00 p.m. to 1:00 p.m.) shifts, and were used to calculate the Globe Temperature and Humidity Index (GTHI). Supplementation did not influence the physiological variables of thermoregulation (p > 0.05). However, there were differences in the GTHI between the shifts, with higher means in the afternoon shift, especially in the less rainy period of the year, where the GTHI reached 92.06 ± 2.74 (p < 0.05). In all periods of the year, the mean values of RT, RR and BST were higher in the afternoon shift (p > 0.05). The respiratory rate (RR) is associated with the annual seasonality of the thermal waters, with higher averages in the afternoons of the rainy season. The positive correlation for rectal temperature, respiratory rate and body surface temperature indicated that buffaloes respond to thermal elevations in the atmosphere (afternoon period) and, consequently, reflect on the GTHI. Supplementation does not influence thermoregulation; the changes observed occurred in response to the region's thermal and rainfall conditions (mainly in the afternoon shift), with higher GTHI values. [ABSTRACT FROM AUTHOR]

Simple Summary: This study aimed to characterize the thermal patterns of cattle raised in three different production systems during the transition period in the eastern Amazon, Brazil, using infrared thermography and by evaluating thermolytic responses. The evaluated systems were silvopastoral (with shade and no access to the bathing area), traditional (without shade and with no access to the bathing area), and integrated (with access to the shade and the bathing area). The thermographic images showed that the silvopastoral system, with shading, provided more favorable thermal conditions compared to the other systems. Physiological analyses revealed that the cattle maintained a rectal temperature within normal ranges in all systems. However, the respiratory rate was higher in the traditional system, indicating possible thermal stress in this environment. The thermal comfort indices indicated moderate stress conditions at times of greater solar intensity in all systems. In general, the results suggest that the silvopastoral system offers better thermal conditions for cattle, providing shade and reducing thermal stress. Thus, management practices aimed at animal welfare and productivity in production systems in the eastern Amazon region can be adopted by ranchers. In the Lower Amazon mesoregion, there are basically three types of production systems: the traditional (without shade and no bathing area), the silvopastoral (with shade and no bathing area), and the integrated (with shade and bathing area). It is considered that the type of production system influences the thermal comfort and productivity of cattle, so this research aims to evaluate the influence of these three types of production systems on the thermoregulation of Nellore cattle. The experiment was carried out on a rural property for raising cattle, located in Mojuí dos Campos, Pará, Brazil, during the transition period (June/July). Thirty bovine males (not castrated, aged between 18 and 20 months, average weight of 250 ± 36 kg, body condition score of 3.5, clinically healthy) were randomly divided into three groups: Silvopastoral System—SS (n = 10), Traditional System—TS (n = 10), and Integrated System—IS (n = 10). Climate variables were collected (air temperature (AT °C), relative humidity (RH %), wind speed (WS, m/s), solar radiation (SR), black globe temperature (BGT °C), and physiological parameters, such as respiratory rate (RR) and rectal temperature (RT)) at 6 a.m., 12 p.m., 6 p.m., and 12 a.m. to determine the thermal comfort situation of the animals. Thermographic images of the environment and animals were captured in order to obtain the body surface temperature (BST) through infrared thermography. The Benezra Thermal Comfort Index (BTCI), Environmental Stress Index (ESI), Equivalent Temperature Index (ETI), and Iberian Heat Tolerance Index (Iberian HTI) were used. The results showed that the silvopastoral system, with shading by chestnut trees and an ample vegetative area, presented better thermal conditions, with an average of 28.98 °C, in comparison with the traditional system (35.93 °C) and the integrated one (34.11 °C). It was observed that the body surface temperature of cattle did not differ significantly between the anatomical regions of the body and the studied systems (p > 0.05). As for the respiratory rate, the traditional system registered higher values, with an average of 41 movements per minute, indicating possible thermal stress (p < 0.05). The thermal comfort indices revealed that all systems presented moderate stress conditions during times of higher solar intensity. It is concluded that the silvopastoral system proved to be more favorable for cattle, providing shade and reducing thermal stress, which may have a positive impact on animal welfare and productivity in this region. [ABSTRACT FROM AUTHOR]