Thermal comfort indices assessed in integrated production systems in the Brazilian savannah

The objective was to evaluate the animal thermal comfort indices from two integrated crop-livestock-forestry (ICLF) systems. For this, temperature-humidity index (THI), black globe temperature and humidity index (BGHI), and the radiant thermal load (RTL) were assessed. Two ICLF (ICLF-1 and ICLF-2) systems and one control system were established. On the ICLF systems, the arboreal component was the eucalyptus tree (Eucalyptus grandisxEucalyptus urophylla; H13 clone), planted in simple wide-spaced rows. The ICLF-1 system had a tree spacing of 14x2m with 357 trees per hectare, and the ICLF-2 had a tree spacing of 22x2m with 227 trees per hectare. The control system had five scattered native trees per hectare, pertaining to Gochnatia and Dipteryx species. The forage component in all three systems was piatA-grass (Brachiaria brizantha cv. BRS PiatA). The experimental design was a randomized block in a sub-subplot design scheme with four replications. The presence of shade provided by the trees offered better conditions of animal comfort when compared with the condition of full sun. The ICLF-1 system, with higher tree density, provided better indicators for thermal comfort, THI, BGHI, and RTL when compared with the condition of full sun, while ICLF-2 was no different than ICLF-1 for BGHI.