Vocalização de suínos como indicativo de bem-estar

Abstract

This work aimed to estimate the welfare of pigs using their vocalization records during rearing in commercial swine farm. A total of 150 barrow pigs were randomly distributed into five drive pens. Pigs were subjected the different stress situations: Thirst (no access to water), hunger (without access to the food), thermal stress (THI exceeding 74). For the control treatment the animals were kept in situation of comfort (animals with full access to food and water, and environment with THI below 70). Acoustic signals were recorded every 30 minutes during a continuous period of three hours, totaling six samples for each stress exposure. The signals were digitized at a frequency of up to 44,100 Hz, for a period of 3 minutes. Later the audios were analyzed using the software Praat ® 5.1.19. The attributes generated from this sofware were the energy signal (Pa ² * s), maximum amplitude and minimum amplitude (Pa), the frequency of pitch (Hz), the sound intensity (dB) and four levels of formants (F1, F2 , F3 and F4), also called harmonics (Hz). It was found that depending on the acoustic attributes the stressor stimuli and its duration, indicate energy and signal strength, frequency of pitch and formants 2 and 4 showed differentiation. The sound attributes of the pigs vocalization varied in different ways depending on the type and duration of the stressful exposure, functioning as an efficient tool to quantify the animal degree of stress.