THE BEHAVIOR OF PRIMIPAROUS SOWS AROUND FARROWING IN RESPONSE TO RESTRAINT AND STRAW BEDDING

The behaviour of 24 primiparous sows around parturition was examined from continuous video-records to investigate the effects of accommodation type (farrowing crate vs pen) and substrate (straw vs no straw), in a factorial experiment, on sow behaviours that may influence piglet survival. The experiment was part of a larger experiment involving 64 sows and litters, which examined the effects of the farrowing/lactation environment on sow behaviour, and piglet survival and growth to weaning. During the 24 h pre-partum, sows spent less time side lying (29.3 vs 42.3% of observations; P<0.01) and more time standing (26.8 vs 17.2%; P<0.05) in the absence of straw bedding compared with in the presence of straw bedding. Sows in crates compared with pens, changed posture more frequently (265 vs 180 times per sow; P<0.01). The occurrence of pawing at the bare floor was greater in crates than in pens (0.6 vs 0.3% of observations; P<0.05), and in the absence than in the presence of straw bedding (0.6 vs 0.3%; P<0.05). Rooting/nosing at the floor/bars occurred less in crates than in pens (4.5 vs 8.1%; P<0.01), and more in the absence than in the presence of straw (11.3 vs 1.3%; P<0.01). The manipulation of straw by sows in the straw-added treatments was recorded during 14.2% of observations. In the 24 h before farrowing, sows performed less 'nesting-like' behaviour (paw, root/nose and straw-directed behaviours combined) in crates than in pens (11.1 vs 16.9%; P< 0.02), while the addition of straw tended to increase prepartum nesting-like behaviour (11.9 vs 16.1%; P<0.08). The data suggest that factors in the environment of the peri-parturient sow affect the quantity of pre-partum nesting-like behaviour, such as root/nose/paw behaviours and manipulation of straw. However, the fact that environments that elicited more maternal behaviour did not promote piglet survival, suggested that piglet survival may be more affected by the structural/thermal environment than by the sow's behaviour.