The effect of the farrowing environment on the duration of farrowing and the incidence of stillbirth is unclear. The likelihood of intra-partum stillbirth (i.e. piglets dying during the birth process) has been shown to increase during prolonged farrowings. It has been proposed that this is a result of asphyxiation when the oxygen supply to a piglet is interrupted through damage to the umbilical cord before the piglet is expelled. Some researchers have speculated that the farrowing environment could be responsible for prolonging farrowing and increasing the rate of stillbirth. Confining sows to farrowing crates may lead to the frustration of natural nest building behaviour causing stress. The release of adrenaline, in response to short-term stress, counteracts the effects of oxytocin, which causes contraction of the smooth muscle. In addition, movement of the sows legs and body help to force out fluids and restriction of these movements may delay the expulsion of the piglets. In this study, farrowings in both a conventional farrowing crate and a wide farrowing crate, which enables the sow to turn around and go through most natural postural changes, were monitored. The authors found no significant difference between the conventional and wide farrowing crate in the interval between piglets, incidence of stillbirth and posture or postural change. In addition, piglet survival and weight gain to 3 days of age did not differ between the two systems. The sows were found to be most active during the first two birth intervals, with progressively fewer postural changes occurring as farrowing continued. Birth intervals were found to be longer, on average, before a stillbirth than before a live birth. It was found that the greater incidence of stillbirths late in the farrowing was associated with a greater proportion of long birth intervals late in the farrowing, and a greater likelihood of stillbirth even for shorter and medium intervals. This suggests that attempts to reduce stillbirth by manipulating the duration of farrowing is more likely to be effective if unusually long birth intervals are eliminated than if birth intervals already in the normal range are shortened. Stillbirths were also found to be more common in longer farrowings which tended to involve larger litter sizes and more long birth intervals of over 60 min. Few studies have shown that provision of additional space during farrowing has a major effect on stillbirth rate or farrowing duration. In addition, there is no clear evidence that provision of nest-building material in a farrowing crate shortens farrowing or reduces stillbirths. The results of this and related studies suggest that greater freedom of movement in the farrowing environment does not consistently produce shorter duration of farrowing or a lower incidence of stillbirth.