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.

摘要 本研究旨在对巴西半干旱区绵羊养殖中的黑球温度（black globe temperature, TBG）与灰球温度（gray globe temperature, TGG）进行表征与对比。试验选用圣伊内斯羊（Santa Inês）与陶泊羊（Doper）两个品种，将试验动物分配至露天日晒与遮阴两种热环境中，每个试验围栏饲养10只试验动物。试验采用完全随机设计，设置2×2因子方案（遮阴环境与日晒环境 × 黑球测温与灰球测温），共开展46次重复观测（即46个观测日）。观测时段内，TBG均高于TGG；在露天日晒环境下，当日13:00时温度达到峰值（48.1℃），同时黑球温湿度指数（black globe temperature and humidity index, BGHI）升至96.7。而TGG的观测结果存在显著差异，同一环境下其峰值温度为37.6℃，对应BGHI为86.2。无论采用哪种测温方式，BGHI值均超出绵羊的适宜舒适阈值。在遮阴环境下，两种球温的变化趋势趋于一致；而在日晒条件下，二者差异显著，黑球温度更高，这源于不同颜色对热辐射的吸收特性差异。