# Shade matters: heat stress alleviation in Gyr and Girolando cows through silvopastoral management in tropical conditions

## TL;DR

This study shows that providing shade through silvopastoral systems reduces heat stress in Gyr and Girolando cows in tropical climates.

## Contribution

The study demonstrates the effectiveness of Eucalyptus urograndis shade in improving thermal comfort for tropical dairy cattle.

## Key findings

- Cows in shaded environments had significantly lower body temperatures, respiration rates, and panting scores.
- Gyr cattle showed better thermoregulatory responses to shade compared to Girolando cattle.
- Discriminant analysis classified animals by system and breed based on physiological traits with high accuracy.

## Abstract

Silvopastoral systems integrating tree cover into pasturelands offer promising strategies to mitigate heat stress in tropical livestock production. This study evaluated the effects of shade from Eucalyptus urograndis on thermal comfort indices in Gyr and Girolando dairy cattle in the Brazilian Cerrado. Forty-eight lactating cows (24 Gir, 24 Girolando) were monitored over two years in two contrasting environments: no shade (full sun) and shade (silvopasture). Thermal indices, including rectal and surface temperatures (measured via infrared thermography), respiration rates, and panting scores, were analyzed alongside environmental data, such as the Temperature-Humidity Index (THI). Cattle under shade consistently exhibited lower body temperatures, respiration rates, and panting scores, with significant differences amplified under heat stress conditions (THI > 74). Though both benefited from shade, Gyr cattle demonstrated better thermoregulatory responses than Girolando. Discriminant analysis accurately classified animals by system (> 92%) and breed (~ 71%) based on physiological traits. These results confirm that tree shade significantly enhances animal comfort in tropical pasture systems and supports the implementation of silvopastoral practices to improve dairy cattle welfare and resilience under climate stress.

The online version contains supplementary material available at 10.1007/s00484-025-03063-7.