The objective of this study was to assess the influence of environmental variables on sound level emitted by piglets, and to quantify the sound bands using dB compared to the conditions of thermal comfort established by the literature. The experiment was carried out at a climatic chamber, where five piglets at nursery stage were housed and submitted to a variation of the ambient temperature ranging from 28ºC to 38ºC and relative humidity ranging from 50% to 80%. Sound level meters were installed to record sound levels, and data loggers to record temperature and relative humidity data. The level of activity was used to quantify the animals' movement by means of image analysis. Correlation and regression analysis were applied in data for statistical analysis. Environmental variables have influence the sound level emitted by piglets when they are exposed to different thermal conditions. The sound levels were established in bands according to the thermal condition in which the animals are submitted. For comfort condition (20 to 23°C), sound level ranges from 70 to 75dB; for alert condition (23 to 30°C), sound level ranges from 60 to 70dB; and for thermal stress condition (above 30°C), it ranges from 55 to 60dB.
animal noise; vocalization; temperature; sound level meter
