Using movement sensors to detect the onset of farrowing

Farrowing is an important economic phase in pig production. In modern pig herds the lack of surveillance at farrowing is a current animal health and welfare problem. One of the clearest signals of impending farrowing is the sow's increased activity caused by nest-building behaviour. Six farrowing crates were equipped with a system to monitor sow activity. Each crate was equipped with a photocell (E3F2, Omron Europe, The Netherlands) placed at a height of 0.6 m. In three crates, a thin-film ferroelectret force sensor (L-series, Emfit Ltd., Finland) was also installed under the sows. The force sensor measured the overall movement of the sows and the photocells were used to detect whether they were lying down or standing up.The mean time sows spent standing was significantly higher in the 24-h interval prior to farrowing than in all the other 24-h intervals monitored (p<0.05). The force sensor recorded a significantly higher number of peaks in the 24-h interval prior to farrowing than in all the other 24-h intervals monitored (p<0.05). Thus, our results indicate that these sensors can serve to measure sow activity with impending parturition and both sensors can provide similar information.