Rivero M Jordana, Pascale Palhares Julio C, Novelli Taisla Inara, Martello Luciane Silva, Pérez-Márquez Simón, Cooke Andrew S
Net Zero and Resilient Farming, Rothamsted Research, North Wyke, Okehampton, Devon, United Kingdom.
Emprapa Pecuaria Sudeste, São Carlos, Brazil.
PLoS One. 2025 Sep 12;20(9):e0331238. doi: 10.1371/journal.pone.0331238. eCollection 2025.
Heat stress is a significant challenge in tropical beef production systems, affecting feed intake, water intake, and overall animal welfare. This study aimed to evaluate the impact of shade provision on the water intake and drinking behaviour of Nellore steers (Bos indicus) in a tropical feedlot environment. A total of 47 steers (~450 kg body weight) were allocated into two groups: one with access to shade (+S) and another without (-S). Individual water intake, drinking behaviour (e.g., frequency, daily patters), and animal performance were monitored over 83 days using automated recording systems. Results showed that -S steers consumed 8% more water per day (p < 0.001), made more frequent visits to the water trough (p < 0.001), but drank less per visit (p < 0.001) and overall spend 39% more time per day drinking (p < 0.001) compared to the + S steers. Despite these differences in drinking behaviour, average daily gain and feed intake did not differ between groups (p > 0.05). Environmental factors like temperature, humidity, and solar radiation affected water intake in both groups. Higher air temperatures increased water intake by boosting drinking frequency, while higher relative humidity reduced water intake by decreasing visit frequency. Shade provision reduced water demand per unit of body weight gain, improving water-use efficiency. These findings suggest that while shade may not directly enhance body weight gain, it can optimise drinking behaviour, reduce water intake, and improve animal welfare in tropical beef production systems.
热应激是热带肉牛生产系统面临的一项重大挑战，会影响采食量、饮水量以及动物整体福利。本研究旨在评估在热带饲养场环境中提供遮荫对Nellore阉牛（印度牛）饮水量和饮水行为的影响。总共47头阉牛（体重约450千克）被分为两组：一组有遮荫设施（+S），另一组没有（-S）。使用自动记录系统在83天内监测个体饮水量、饮水行为（如频率、每日模式）和动物生长性能。结果表明，与+S组阉牛相比，-S组阉牛每天饮水量多8%（p<0.001），更频繁地前往饮水槽（p<0.001），但每次饮水量较少（p<0.001），且每天总体饮水时间多39%（p<0.001）。尽管饮水行为存在这些差异，但两组之间的平均日增重和采食量没有差异（p>0.05）。温度、湿度和太阳辐射等环境因素影响两组的饮水量。较高的气温通过提高饮水频率增加饮水量，而较高的相对湿度通过降低前往饮水槽的频率减少饮水量。提供遮荫降低了单位体重增加所需的饮水量，提高了用水效率。这些研究结果表明，虽然遮荫可能不会直接提高体重增加，但它可以优化饮水行为，减少饮水量，并改善热带肉牛生产系统中的动物福利。
