Learning how to eat like a pig: effectiveness of mechanisms for vertical social learning in piglets

We investigated which mechanisms of learning about foraging from the mother are important in piglets, Sus scrofa. The first experiment compared observation of the sow versus participation during eating. Piglet pairs could observe (observation piglets) or participate (participation piglets) with the sow while she was eating a flavoured feed in a test room for 10 min/day for 5 days. Piglet pairs that could eat food without cues from the sow and control piglets that had neither cues nor food were also exposed to the test room with their sow present but unable to eat. Piglets were tested over 3 days for 90 min/day and could choose between the sow’s food and another flavoured food. Observation and participation piglets showed shorter latencies to eat and higher consumption of, and preference for, the flavour eaten by the sow than control and no-cue piglets. The second experiment compared local versus stimulus enhancement. Piglets observed the sow eating a flavoured feed from one of two feeders on different sides of the room for 10 min/day for 5 days. During the test phase there was a match or mismatch between location and the flavoured food eaten by the sow. Match piglets showed more behaviour towards, and a higher consumption from, the feeder where the sow was eating, while this was not true for mismatch piglets, suggesting a role of both local and stimulus enhancement. Observation, participation, local and stimulus enhancement thus all seem important for piglets to learn from the sow.