Medida de vocalização de suínos (Sus scrofa) como um indicador de gasto energético

Abstract

In intensive pig production stressing managements such as weaning, teeth cutting and castration may reduce animals’ welfare status and lead to decrease in productive performance. Vocalization is a useful tool to identify stressful conditions in swine production. The objective of this research was to quantify the energy expenditure of vocal expression of reared pigs, in distinct stress conditions. Pig vocalizations in seven conditions were analyzed: normal, with hunger, very hungry, with pain, very painful, with fear and with much fear. The sound signal capture was done using an electret microphone positioned 1.0 m above the animals and a laptop where the signals were digitalized by the sound hardware and recorded at a frequency up to 44,100 Hz. For analyzing the recorded signals the Matlab® environment and the software Audacity 1.3.0 were used. Vocalization sound intensity was higher in stressful conditions. The energy of the vocal sound was 0.107 kcal/ s for pigs in normal condition, increasing considerably as the animal reaches high intensity of stress exposure, up to 7.602 kcal/s for pigs submitted to high pain. The duration of vocalization was also higher in stressful conditions, vocal expression related to pain and higher pain represented 3.7 and 3.6 times more duration than those related to piglets in normal conditions. These results showed that there is energy expenditure when the pig vocalizes and that this value increases as function of the stress exposure.