A note on the effects of additional sow gruntings on suckling behaviour in piglets

Abstract The aim of this project was to study, if it is possible to stimulate suckling in piglets kept with their mother to suck by exposing them to a recorded grunting of a sow, and if so, to study if they act normally when their own mother is grunting. Finally, we wanted to find out how the piglets behave when they can hear two different grunting sounds simultaneously, especially if the grunting peaks appear at different times. A recording of the sow grunts was played back with a tape recorder to the piglets 40 min after the start of the last suckling bout. Eight litters of eight crossbred Yorkshire-Swedish Landrace sows at the age of 1 and 3 days were studied. The test was repeated four times during the day and both the sound of the mother sow and the sound of an alien sow were used. The behaviour of the piglets and the sow were recorded on video during the entire test. The behaviour during two natural sucklings was also recorded. The recorded sow grunts were played back to the piglets a total of 55 times. When comparing the sucklings with and without the playback, there seemed to be less piglets sucking and more piglets off the udder or sleeping at the udder before the sow’s grunting peak, when the grunting was played back, than during the sucklings without the playback. There were no differences during or after the grunting peak. In this study, the variations within groups were so large that no significant differences were obtained. However, the results suggest that additional sow gruntings might be able to affect piglet suckling behaviour.