Abstract
The aim of the present study was to analyse grunts of the sows and to extract parameters from the time and frequency signals in nursing behavior. Five crossbred $Landrace{\times}Yorkshire$ sows were used on day 5 or 6 postpartum. The grunts and the behaviors of the five sows were recorded with five digital camcorders. Three parameter groups [Group I: Formant vector alone, Group II: Formant vector+parameters from time signal, Group III: Formant vector+parameters from time signal-parameters eliminated by stepwise discriminant analysis backward (SDAB)] with parameter vectors extracted from single grunts in the maximum grunting rate period were used for individuality of the sows. The parameter groups were compared by a discriminant function analysis. The classification system adopted in the Group II represented the higher discriniation rate than those in other groups (Group I: 63.3%, Group II: 83.0%, Group III: 80.0%). This study demonstrated that formant, intensity, and pitch were available sound parameters for individuality of the sows during nursing behavior.
