THE EFFECT OF PLAYBACK VOLUME AND DURATION ON THE RESPONSE OF SOWS TOPIGLET DISTRESS CALLS

The effect of variation in playback volume and duration on the respons es of recently farrowed sows to a recorded piglet squeal was evaluated in two experiments. In Experiment 1 the squeal was played back at sof t (76-77 dB), normal (84-86 dB) or loud (92-95 dB) volumes as the sow was kneeling prior to lying down. Sows took longer to lie down in resp onse to loud playback than normal or soft playback, and were more like ly to sit or stand in response to loud playbacks than normal or soft p laybacks. In Experiment 2 the recorded squeal was played back at norma l volume for 30, 60 or 120 s, together with a control of no playback. Sows took longer to lie down in response to sound playback compared wi th no playback, but there were no significant differences between the three durations. Similarly, sows were more likely to sit or stand in r esponse to sound playback than no sound playback, but there were no di fferences between the three durations of playback. These results indic ate that the important acoustic properties of a piglet distress call a re its sudden onset and high intensity, and that prolonged calling by a piglet is unlikely to cause a sow to stand.