Straw promotes nestbuilding and facilitates farrowing

This post presents the highlights and abstract of a recent paper by Westin et al.:

Westin, R., Hultgren, J. Algers, B. In press. Strategic use of straw increases nest building in loose housedfarrowing sows. Appl. Anim. Behav. Sci.


• Nest building behaviour and farrowing duration were studied in 138 sows.
• A large quantity (15–20 kg) of straw given once was compared to small daily amounts.
• Time spent nest building during 18 h pre-partum was increased by 19%.
• A 1-h increase in time spent nest building reduced the farrowing duration by 12%.


In spite of domestication, sows are still genetically programmed to perform nestingbehaviour close to farrowing. In order to facilitate nest building, a method for a strategic useof large quantities of straw has been developed by Swedish piglet producing farmers. Theobjectives of the present study were to quantify the effect of strategic use of 15–20 kgof chopped straw given once 2 days prior to expected date of farrowing, compared tosmall daily amounts (0.5–1 kg) and 2 kg close to farrowing (controls), on the nest buildingbehaviour and the duration of farrowing. The behaviour from 18 h pre-partum until 1 h afterbirth of first piglet and the duration of farrowing was continuously observed in 138 videorecordings from 4 commercial farms. On each farm, 20–34 sows (parity ≥ 2) were stud-ied during one or two consecutive lactations. Compared to controls, strategic use of strawtriggered the sows to start nest building earlier and increased the total time spent nestbuilding pre-partum by 19% (p = 0.039). Sows given large amounts of straw also performedless nesting behaviours during the first hour after birth of the first piglet. This shows thatnest building is affected not only by the presence of straw, but also by the quantity of strawprovided, and that 2 kg of chopped straw seems to be too little to make the sow terminatenest building well in advance of farrowing. There was no significant effect of treatment onthe duration of farrowing but a strong negative association was found between time spentnest building pre-partum and the duration of farrowing regardless of treatment. The modelpredicted a 1-h increase in total nest building time pre-partum to be associated with a 12%(95% CI = 4–19%) shorter duration of farrowing (p = 0.004).

Nestbuilding sows
Nestbuilding sow (Photo by Rebecka Westin)
Farrowing sow and piglets on straw (Photo by Rebecka Westin)
Farrowing sow and piglets on straw (Photo by Rebecka Westin)