Vocalization analysis during the castration of pigs

Castration is usually carried out on young male pigs by surgical means to prevent boar taint in older males. The specific structure of vocalizations of piglets may provide some information on the extent of pain experienced by the animal. A total of 96 piglets from 24 litters out of a commercial herd were allotted to four different treatments between the age of d 7 and 19: (a) castration without anesthesia [C], (b) castration with local anesthesia [CA], (c) fixation without anesthesia [F], (d) fixation with local anesthesia [FA]. Vocalizations were recorded with a calibrated microphone (B&K4133) and a DAT recorder (SONY‐TCD‐D8). Analysis was done with Entropics Signal Processing System (ESPS5.0) software on a workstation (SGI Indy) and provides a multiparametric description of call characteristics. Plasma catecholamines were analyzed from plasma taken immediately after each treatment. Call structure within vocalizations of castrated piglets [C] changed during periods of tearing and cutting of the spermatic...