The use of vocalization signals to estimate the level of pain in piglets

Abstract

Pain is considered a condition that most affect the welfare of animals and its measurement is seen as a difficult task. This research aimed to determine the level of pain in pigs by their vocalization. It was recorded the vocalizations of 20 male piglets under normal circumstances (I), marking by Australian method (II), tail trimming management (III), and castration (IV). A unidirectional microphone and a digital recorder were used to record the sound signals. The results suggested that Pitch frequency (Hz), the maximum amplitude (Pa), and intensity (dB) increased from pain-free pigs to the marking procedure; and from marking to both tail trimming and castration The tail trimming and castration vocal response did not differ.