Abstract Tropical zones currently produce the majority of the world’s agricultural food; however, their thermal environment poses a challenge to animals. In this context, silvopastoral systems (SPS) have been proposed to provide animals with milder microclimates owing to their shaded areas. To evaluate the impact of the silvopastoral system on the behavior, gonadosomatic development, and endocrine profile of young beef bulls, as well as to relate these characteristics to thermal comfort conditions across different seasons. Conducted over 13 months in a high-altitude tropical area in Brazil, the study involved 40 beef bulls (10.5±1.9 months; 222.5±34.5 kg BW), divided into full sun (FS; n=20) and SPS (n=20). Weather stations measured bioclimatic variables, and electronic collars permanently monitored animal behavior. Monthly measurements included hormonal profiles, live weight, and scrotal circumference. Statistical analyses used a mixed linear model (α=5%).SPS provided a milder microclimate, enhancing thermal comfort ( P <0.05). The system influenced the time spent walking and resting ( P <0.05). Bulls in FS ruminated longer at night and in the early morning than in SPS. Even in hotter seasons, FS bulls walked more than those in SPS ( P <0.05). Serum cortisol and testosterone levels were similar between groups; however, FS bulls had higher serum T3 levels ( P <0.05) without significant anabolic effects. Both groups showed similar live weight and scrotal circumference development. SPS fosters a more favorable microclimate, improving animal welfare and behavior while maintaining productive traits, suggesting its potential to enhance the resilience of production systems.
Moraes et al. (Sun,) studied this question.