Silvopastoral System Mitigates the Thermal Stress and Benefits Water Buffaloes’ Comfort in the Eastern Amazon, Brazil

Twenty female Murrah buffaloes between four and five years old were randomly distributed into two groups (traditional system - TS and silvopastoral system - SPS) with 10 animals each and an average weight of 377.78 kg and 356.10 kg, respectively, for the TS and the SPS. The TS had a management regime with no canopy cover and no shade coverage over the drinking and feeding troughs. In the SPS, Racosperma mangium (Fabaceae) trees were used to provide shade, with an estimated 10% shading. The physiological variables studied were rectal temperature and respiratory frequency measured every three days from 6 to 7 AM and from 12 to 1 PM. The following environmental indices were calculated: Temperature Humidity Index (THI), Black Globe Humidity Comfort Index (BGHI), and Benezra’s Index of Adaptability (BIA). The THI values were high in both management systems, between 76.27 and 86.73, higher than the limit of comfort level for buffaloes, which is 75. The maximum values of BGHI for the afternoon were 92.0 and 87.62, for TS and SPS, respectively, and the maximum values of BIA for the afternoon were 4.4 and 3.8, for TS and SPS respectively, which were higher than the critical level of adaptability and represented an uncomfortable condition that causes a reduction in animal performance. It was concluded that the silvopastoral management system is more efficient in terms of animal comfort for the female buffaloes as a result of the shade that provides a more amenable microclimate.