Caracterização da variabilidade espacial dos índices de conforto termico para vacas leiteiras em sistema de confinamento compost barn no semiárido sergipano.

Abstract

The objective of this work was to characterize the thermal environment for dairy cows confined in the Compost Barn (CB) facility on a private property in the municipality of Nossa Senhora da Glória/Sergipe. The experiment was remotely monitored for three months using automated equipment developed by the Department of Engineering at UFS/São Cristóvão. From there, the Temperature and Humidity Index (ITU) and the Globe Temperature and Humidity Index (ITGU) were estimated using formulas inserted in the equipment's database. Thus, the values obtained were compared with the ideal thermal comfort conditions for dairy cattle, based on validated methodologies. For the interpretation of the obtained results, the individual control chart was used, which is one of the Statistical Process Control (SPC) tools, elaborated using the Minitab 19 program. According to the results obtained in the present research, the values of THI always remain above that defined by the literature as a comfort condition (less than 68), having varied, in both environments (internal and external to the compost barn), from 72.8 to 83.9, oscillating the animals to situations classified as mild stress to moderate stress. For ITGU, the values found classified the thermal situation of the spaces between comfort situation and light thermal stress (interior of the composting barn), with values between 70.6 to 77.3 and for the external environment, the observed values characterized the environment as thermally comfortable on vacation (75.2) to a dangerous condition (85.3), that is, high thermal stress. Thus, for the ITGU index, only at dawn and at night found satisfactory environmental conditions for raising dairy cattle, however, in the morning and afternoon periods the animals were affected by thermal stress from a mild level to the situation of danger. Regarding the THI, the required values were unsatisfactory in relation to those in the literature.