Spatial modeling via geostatistics and infrared thermography of the skin temperature of dairy cows in a compost barn system in the Brazilian semiarid region

The aim of the study was i) to determine the spatial variability of the skin temperature of dairy cows in a compost system and ii) to evaluate the thermal comfort conditions of confined animals. Skin temperature (T-skin,degrees C) was recorded in three animals at 9:00 am (morning) and the measurement was repeated at 3:00 pm (afternoon) using a thermographic camera (model FLIR i60). T-skin data were submitted to descriptive statistics, geostatistics, and later elaborated kriging maps. When comparing the T-skin mean at 9:00 am and 3:00 pm, for animal 3, there was a reduction of 0.30 degrees C in the afternoon shift, as a result of the individual's position concerning the forced ventilation system. The use of the geostatistics technique made it possible to verify the occurrence of a strong spatial dependence between the skin temperatures of cows raised inside a facility with a compost barn system, with the Gaussian model showing the best fit of the data (R-2>0.90), for the morning and afternoon recording shifts. The characterization of the spatial variability of the T-skin of dairy cows allowed us to identify the comfort conditions of the animals housed in the compost barn systems.