The influence of trees on the thermal environment and behaviour of grazing heifers in Brazilian Midwest

Abstract

The intensification of the livestock production system has gained prominence over the last decades. In addition to the reduction of grazing areas and increased productivity per hectare, the intercropping involving forest tree species and ruminants has been established as a sustainable production model, generating income and valuation of natural capital. Besides the social, economic, and environmental aspects, the animal welfare is a noteworthy factor. The objective of this study was to evaluate the microclimatic conditions in an open-pasture and in silvopastoral systems, considering the Temperature Humidity Index (THI) and alterations in animal behavior. Three different pasture arrangements were analyzed in this study: total absence of trees in an open-pasture (ArrA), presence of peripheral trees (Eucalyptus spp.) along the border fences (ArrB), and an intensive wooded area aggregated with pasture (ArrC). A herd of 24 crossbreed heifers (3/4 and 7/8 Holstein-Girolando breed) was evaluated. Behavior data were collected every 15 min starting at 08 h00 with readings ending at 16 h00. THI was used to evaluate the environmental comfort. The THI found in the system with open-pasture and in the two systems with silvopastoral arrangement reached critical levels. The two arrangements with eucalyptus rows were not capable of eliminating heat stress in the conditions found in the north region of Mato Grosso State although better conditions were obtained under the tree canopy. The differences between the microclimatic variables for the three arrangements modified the behavior of the animals regarding their location and activity, except for water consumption.

Characterizing heat stress on livestock using the temperature humidity index (THI)—prospects for a warmer Caribbean

“…the use of vitamins, electrolyte and mineral supplementation including chromium and zinc (Lin et al 2006); and exploring more climate resilient strains (Cahaner and Leenstra 1992;Lin et al 2006 (Lopes et al 2016). Other options include night grazing with adequate lighting and security; nutritional management, such as dietary supplementation; and breeding research to assess for heat tolerance as well as milk production (Galukande et al 2013).…”

Improved grazing activity of dairy heifers in shaded tropical grasslands

“…NAVARINI et al (2009) studied beef cattle (nelore) under full sun, in small forest areas, and under isolated trees and recorded body surface temperatures of 35.3, 34.3, and 34.7°C, respectively. However, in Midwest Brazil, with air temperatures reaching 45ºC at noon, definite measures need to be incorporated to mitigate these conditions and improve animal productivity (LOPES et al, 2016). To achieve satisfactory results Mello et al in the animal production, factors such as grassland management, forage allowance, and adequate tree population and distribution need to be considered.…”

Physiological and behavioral responses of dairy heifers in an integrated-crop-livestock-forestry system

“…The microclimatic conditions in a silvopastoral systems and its effects on heifers grazing behavior were evaluated by Lopes et al (2016). The average temperature were higher than 30°C during the experimental period, and the two strategies with Eucalyptus rows adopted were not able to mitigate the heat stress conditions.…”