Ambience of Sheep Submitted to Different Breeding Environments and Global Temperatures

Abstract

The aim is to characterize and to compare the black (TBG) and gray (TGG) globe temperatures in the production of sheep in the Brazilian semi-arid, using Santa Inês and Doper breeds, distributed in two thermal environments (exposed to the sun and shaded), containing 10 animals in each picket. The experimental design was completely random, 2 x 2 factorial scheme (shaded environment and sun x black and gray globe) in 46 replicates (evaluation days). There was an increase of the TBG in relation to the TGG during the evaluation times, with maximum temperature (48.1°C) at 1p.m. in the environment exposed to the sun, concomitantly with elevation of the black globe temperature and humidity index-BGHI (96.7). The result was distinct for TGG, with a maximum temperature of 37.6°C and BGHI of 86.2 in the same environment. Regardless of the thermometer used, the BGHI values exceeded the considerable comfortable limit for sheep. Under shaded conditions, the globe temperatures showed similar behavior. In sunny conditions, these temperatures diverged, higher in the black, because of the absorption conditions of the thermal radiation of the different colors.

Productive, physiological and behavioral sheep profiles housed on facilities with different roofs in the Amazon region

“…The relative humidity of the air had the opposite behavior to air temperature. It was higher in the shed with FC tiles, a fact that may be associated with lower air temperature and, from a thermal point of view, this inversion is beneficial to the animals, favoring the processes of latent heat transfer, contributing to the maintenance of thermoregulatory mechanisms of homeothermic animals, especially under high-temperature conditions (Furtado et al 2018). However, the average relative humidity in the sheds was high, above the ideal for sheep (Eustáquio Filho et al 2011;Marques et al 2021), which can compromise their vital functions since the high relative humidity associated with high temperatures make it difficult to lose heat in the sensitive form, as the atmospheric air becomes saturated with water vapor, forcing the animal to resort to latent heat loss mechanisms, with energy expenditure and increased physiological variables (Leite et al 2019).…”

“…Carneiro et al (2015) found that environments covered with recycled tile (75% polymers and 25% aluminum) had an average temperature inside the facility (27.59 °C) higher than that of fiber cement (27.12 °C). According to Furtado et al (2018), darker colors have a greater capacity to absorb long and short-wave radiation, heating up more and increasing their absorptance and transmittance capacity.…”

“…The roof is an element that helps in thermal protection, providing comfort inside the facilities, having a low acquisition and installation cost, high reflective capacity, low absorption coefficient, and thermal conductivity (Furtado et al 2018). In this perspective, several materials have been used to cover the sheepfolds (Kabavata et al 2013), such as fiber cement and polyvinyl chloride tiles, which are capable of promoting a reduction in the internal temperature of the facilities (Oliveira et al, 2005), providing better comfort conditions.…”

Comparação de termômetro de globo negro e cinza em diferentes ambientes

“…Para Furtado et al (2018), o uso do globo cinza entra como importante ferramenta alternativa ao uso do globo negro, por apresentar dados mais reais, principalmente em ambiente sombreados, a serem utilizados nos índices de conforto térmico para animais que apresentam adaptabilidade as condições ambientais e de manejo empregados. Pois, vários são os relatos, que ao utilizarem o globo negro, tido como o globo padrão, para cálculo de ITGU, reportam índice elevado, principalmente em condições ensolaradas, relatando condições que fogem da zona de conforto térmico, superestimando as condições sentidas pelos animais.…”