Effects of heat stress on feeding and drinking behavior of confined Texel sheep in a tropical environment

Abstract

This study aimed to evaluate the effects of heat stress on feeding and drinking behavior patterns of confined Texel sheep under tropical environmental conditions. Forty Texel ewes were monitored for 72 days in an experimental facility equipped with automated systems for individual feed and water intake recording. Meteorological variables such as air temperature, relative humidity, and temperature-humidity index (THI) were recorded daily. Behavioral parameters assessed included number and duration of visits to feeders and waterers, as well as effective intake. Principal component analysis (PCA) was used to explore patterns and discriminate behavior across THI categories. Results indicated that higher THI values, especially in the afternoon, significantly influenced water and feed intake patterns. Animals exposed to more stressful conditions showed increased water intake, more frequent visits to waterers, and shorter feeding events. These behavioral adaptations are consistent with thermoregulatory strategies aimed at reducing internal heat load and maintaining homeostasis. Despite the challenging conditions, no metabolic disorders or critical heat stress indicators were observed, likely due to environmental management that provided shade and protection from direct sunlight. Multivariate analyses effectively discriminated between thermal environments based on behavioral parameters, confirming that heat stress alters feeding and drinking behavior in confined sheep. These findings highlight the importance of monitoring animal behavior as an indicator of thermal comfort and underscore the need for adaptive management strategies in confinement systems to ensure animal welfare and maintain productivity in tropical regions.