Effects of seasonality and different rearing systems on the behavior and thermal comfort of sheep in the northern region of Brazil, eastern Amazon.

Climate change causes physiological, metabolic, and behavioral changes that affect animal welfare (AW). Therefore, the objective of this study was to evaluate the effects of seasonality and different breeding systems on the behavior and thermal comfort of sheep in northern Brazil, in the eastern Amazon region. We used 20 Santa Inês sheep, non-castrated, non-pregnant, and non-lactating females. They were randomly divided into two systems: Traditional System (TS; n = 10), Silvopastoral System (SP; n = 10). The behavioral assessment was carried out from 6 a.m. to 6 a.m., with behavior recorded every 5 min, considering the morning (MH), afternoon (TD), night (NT), and dawn (MD) shifts, during the most and least rainy periods. The Temperature and Humidity Index (THI) was calculated. The data were evaluated at a 5% significance level using the software Statistical Analysis System (SAS). THI was higher during the afternoon shift, indicating severe stress (89%). There was a difference (p < 0.001) in the ingestive and idle behaviors of the sheep, influenced by seasonal periods, day shifts, and production systems evaluated. Grazing occurred with greater intensity in the less rainy period (64.81%) compared to the rainiest period (35.19%), being more pronounced during MD (42.40%) and MH (39.23%). Standing rumination was higher in the rainy season (56.71%) and in the NT (77.28%), while in the less rainy period, it occurred during MH (100%). It is concluded that rearing sheep in an SP favored a greater expression of AW behaviors, contributing to higher production efficiency.