Figure 1. Schematic representation of experimental treatments to the sows: C.

 = control received the handling sessions but no voice. V1+ and V2+ = experimental groups which received both handling and the broadcast of a human voice reading the text through a loudspeaker. In order to make sure the results were not just due to one voice quality, two experimenters (E1 and E2) performed the handling, wearing the loudspeaker (in order to have standardized acoustic parameters) that broadcast their own voice. We acknowledge Ms. Vanessa Andre for providing the drawing of pigs.