Fig. 7

Estimated marginal mean and standard error for duration (seconds) of piglets’ vocalizations per second during castration. Different vocalizations of piglets are presented as total vocalizations (a, n = 179), grunts (b, n = 179), screams (c, n = 179), and squeals (d, n = 179). Piglets had been treated with local anesthesia (LA) or sham injections (NO LA) and they were restrained either with a tubular bench (TUBE) or a castration rack (HANGING)