Effects of feed-back from the nest on maternal responsiveness and postural changes in primiparous sows during the first 24 h after farrowing onset

In order to elucidate whether feed-back from a farrowing nest affects the sows' activity level and responsiveness to piglets during the first 24 h after the onset of parturition, 18 primiparous Landrace x Yorkshire sows were given the opportunity to build a farrowing nest of peat, straw and branches in Schmid pens. Eight treatment sows then had their nest removed 8-10 h after the onset of nest-building and again every 4 h until farrowing began, whereas 10 control sows were allowed to keep the nest. During the first 24 h after birth of the first piglet the behaviour of the sows and piglets was observed and heart rate of the sows monitored using a transmitter belt and watch receiver. The frequency of postural changes and a maternal responsiveness index was calculated. In addition, time from birth of each piglet until it suckled for the first time was calculated. In the treatment group there was a constantly higher level of maternal responsiveness (P < 0.0001), but the frequency of postural changes did not differ from that of control sows. The timing of maternal responsiveness was not affected by treatment, but in both treatment groups maternal responsiveness was significantly higher during the first 2 h after birth of the first piglet than in the following 6 h (P < 0.0001). Hereafter (8-24 h postpartum) the maternal responsiveness significantly increased (P = 0.05). The frequency of postural changes also was higher during the first 2 h (P < 0.0001) than in the following 6 h after which it increased again (P = 0.05). Heart rate gradually declined over the first 8 h after birth of the first piglet (P < 0.0001) after which it stayed level. Piglets from treatment sows took significantly longer to suckle for the first time compared to piglets from control sows (P < 0.05). The decrease in activity and maternal responsiveness shortly after parturition has begun is likely to be advantageous for the piglets as it reduces the risk of piglet crushing while at the same time giving early access to the udder and to warmth from the sow. The results emphasise the importance of a proper farrowing environment and the opportunity to construct a nest, particularly in loose housed sows where the survival and vigorousness of the piglets depend greatly on the behaviour of the sow because the piglets are not protected by pen features as is the case in farrowing crates. (C) 2003 Elsevier Science B.V. All rights reserved.