Influence of environmental stimuli on nest building and farrowing behaviour in domestic sows

Abstract

The effects of biologically relevant stimuli on nest building and farrowing behaviour were investigated. Effects of floor type (sand vs. concrete) and substrate type (straw feeder vs. no straw feeder) were examined using a 2×2 factorial design with nine replicates of four multiparous sows. From 1 week prepartum until 2 weeks after farrowing, sows were penned individually in roofed 7.6 m 2 `get-away-pens'. Video recordings of sow and piglet behaviour in the nest area were made for 24 h on Days 2, 1 and 0. Observations of the timing and the quantity of the prepartum rooting and nest building behaviour as well as of the behaviour during farrowing were made. The timing and quantity of the prepartum rooting and nest building period were affected by the provision of straw. Straw increased the duration from initiation of the state of nest building and rooting until farrowing (nest building: 18.0±1.1 vs. 14.1±1.1 h; P<0.05; rooting: 17.2±2.3 vs. 11.5±1.6 h; P<0.05). In addition, sows with straw provided had a longer prepartum rooting period and nest building state (rooting period: 15.9±3.2 vs. 6.7±2.2 h; P<0.05 and nest building state: 16.7±1.1 vs. 13.4±1.1 h; P<0.05). Access to straw also led to an increased quantity of rooting (6.2±0.4 vs. 4.5±0.4 h; P<0.05) and activity (8.6±0.6 vs. 6.5±0.6 h; P<0.05) during the prepartum nest building period. Furthermore, in experienced sows sand tended to increase the time from termination of nest building until farrowing (2.5±0.5 vs. 1.2±0.5 h; P<0.06). Provision of sand had no consistent effects on farrowing, whereas straw led to a shorter interval from first to third piglet (47±12 vs. 111±19 min; F 1,26=8.90; P<0.01), less piglets born at the time of the last postural change during farrowing (1.3±0.3 vs. 3.2±0.6 piglets born; F 1,27=5.44; P<0.05) and performance of less nest building during farrowing than sows without straw (1.9±0.4 vs. 4.1±0.9 observations; F 1,32=6.89; P<0.05). Furthermore, significant correlations were found between timing of nest building and farrowing behaviour as well as postpartum maternal behaviour. In conclusion, provision of environmental stimuli relevant for nest building had effects on the timing and quantity of nest building, decreased duration of the first part of farrowing as well as a decreased risk of crushing of piglets shown by less nest building and less piglets born before the last postural change during farrowing. The effects were also extended to the postpartum period. In agreement with the hypothesis of regulation of nest building put forward by Jensen [Jensen, P., 1993. Nest building in domestic sows: the role of external stimuli. Anim. Behav. 45, 351–358.] straw had most profound effect, but sand seemed to give important feedback as well.