THERMOGRAPHIC PATTERNS IN AN EXTENSIVE LIVESTOCK SYSTEM DIAGNOSED BY INFRARED THERMOGRAPHY IN WESTERN PARÁ STATE, AMAZONIA, BRAZIL

Abstract

The objective was to identify thermal patterns in the soil-plant-animal system using infrared thermography to subsidize strategies for improvement of livestock management techniques in a rural property in western Pará. We carried out the capture of thermographic images of the following targets: animal, pasture, soil and secondary forest, in August. We analyzed climatic data, considering the homogeneous historical series (1979 to 2009), as well as agrometeorological data to evaluate the weather conditions on field collections days. The Temperature and Humidity Index (THI) was used to evaluate if the animals were in conditions of thermal comfort. The generated thermograms were analyzed in the program Flir Tools, 6.3v, with thermal patterns considered in decreasing order, identified by the colors: white, yellow, red and green. The month of August, according to the climatology of the region, marks the reduction of rainfall, reinforcing that the thermographic images at around 3:00 p.m. local time presented responses coherent with the thermal-water condition in the imaged targets at that moment in time. The hottest target was the soil, confirmed by the higher thermal amplitudes. The energetic losses of the animals were also high due to the lack of arboreal vegetation, conditioning the animals to thermal stress, confirmed by the THI. We concluded that areas with secondary forest and pasture present lower temperatures than the animal and exposed soil targets. Infrared thermography was shown to be a precise diagnostic tool under the conditions in which the targets are found, indicating reduced thermal amplitudes in vegetated targets and high variations in exposed soil or degraded pastures.KEYWORDS: Degraded pasture, Homeothermia, Thermal regulation.