Browsing by Author "Mikkola, Aino"

Before parturition the wild boar uses plant material to build a nest, which provides the piglets shelter and keeps them warm. Despite domestication, this behaviour has remained as an important part of maternal behaviour in the domestic pig. Nest building behaviour has a big impact on modern pig production, because the possibilities to practise this behaviour affect the sow and the piglets in various ways. In this study, we investigated nest building behaviour in a group farrowing system. We also studied how nest building behaviour is associated to the sow’s physiology and performance. A total of 31 farrowings of 23 group-housed sows were investigated. The nest building behavior and the location of the sows were monitored continuosly starting 24 hours prior to farrowing. When the sow farrowed, blood and colostrum samples were collected to assess the concentrations of progesterone and immunoglobulins. Also the duration of farrowing, the yield of colostrum and the piglets’ growth, colostrum intake and mortality were observed. The sows had excellent conditions for nest building, because they could move freely in their own group farrowing department and had access to large amounts of straw to use as a nest building material. The total duration of nest building behaviour and the way it was distributed varied greatly between sows. Nest building behaviour started on average 23 h 7 min before farrowing and ceased approximately 18 min before farrowing. The mean total duration of nest building behaviour during 24 hours before farrowing was 4 h 29 min. Most of the nest building behaviour, 3 h 32 min, occurred 12–0 h before farrowing and the peak was seen 6–4 hours prior to farrowing. Younger sows started nest building behaviour earlier and spent less time in the pens than older sows. Starting nest building behaviour earlier correlated with a shorter duration of farrowing and, to a lesser extent, with a smaller number of stillborn piglets. Abundant nest building during 24–12 hours before farrowing tended to correlate with lower piglet mortality in the age of 1–3 days. Opposite to our assumptions, abundant nest building during 12–0 hours before farrowing correlated with poorer piglet growth. Nest building behaviour wasn’t related to colostrum yield and intake or the concentrations of progesterone and immunoglobulins. In conclusion, the total duration of nest building behaviour was greater in group farrowing system than in previously studied systems (farrowing crate, loose farrowing pen). Especially the early start of nest building had a positive effect on sows’ performance.