Monthly Archives: October 2015

How much straw is enough?

Jensen, M.B., Herskin, M, Forkman, B, Pedersen, L.J., 2015. Effect of increasing amounts of straw on pigs’ explorative behaviour. Applied Animal Behaviour Science 171, 58–63.


  • We investigated the effect of straw amount on pigs’ time spent manipulating straw.
  • We investigated the effect of straw amount on pigs’ simultaneous straw manipulation.
  • Increasing straw from 10 to 430 g/pig/day increased both measures.
  • Increasing straw above approx. 250 g did not significantly increase the behaviour further.


According to European legislation, pigs must have permanent access to sufficient quantity of material to enable manipulation activities. However, few studies have quantified how much straw is needed to fulfil the requirements of growing pigs. We investigated the effect of increasing amount of straw on pigs’ manipulation of the straw, and hypothesised that after a certain point increasing straw amount will no longer increase oral manipulation further. From 30 to 80 kg live weight, pigs were housed in 90 groups of 18 pigs in pens (5.48 m × 2.48 m) with partly slatted concrete floor and daily provided with fresh uncut straw onto the solid part of the floor. Experimental treatments were 10, 80, 150, 220, 290, 360, 430 or 500 g straw per pig and day. At 40 and 80 kg live weight, the time spent in oral manipulation of the straw by three focal pigs per pen (large, medium and small sized) were recorded along with the percentage of pigs manipulating straw simultaneously. This was recorded in three 1-h intervals (1 h before and 1 h after straw allocation in the morning, as well as from 17 to 18 h in the afternoon). With increasing quantity of straw provided, we found a curvilinear (P < 0.01) increase in the time spent in oral manipulation of the straw. Smaller pigs spent more time manipulating straw than larger and medium sized pigs (367, 274 and 252 s/h for small, medium and large sized pigs, respectively; P < 0.001), and pigs spent more time manipulating straw at 40 kg than 80 kg live weight (356 vs. 250 s/h; P < 0.001). At both live weights, pigs spent most time manipulating straw during the hour after allocation of straw. Similar effects of increasing amounts of straw were found for the percentage of pigs engaged in simultaneous manipulation of the straw. Post hoc analyses were applied to estimate the point, after which additional straw did not increase manipulation of straw any further. For the time spent manipulating straw the estimated change point was 253 (approx. 95% confidence limits (CL) 148–358) g straw per pig and day. For the number of pigs simultaneously manipulating straw the change point was 248 (CL 191–304) g straw per pig and day. These results show that increasing the quantity of straw from minimal to approximately 250 g per pig and day increased the time spent in oral manipulation of the straw, as well as the occurrence of simultaneous straw manipulation.
Hence, data from the current experiment identified 250 g straw per pig per day as the amount of straw where a further increase in straw provision did not further increase neither time spent on oral manipulation of straw, nor the percentage of pigs simultaneously manipulating straw. This suggests that, within the current housing system and using this criterion, this amount of straw may be the biological turning point for increasing oral manipulation of straw.

5th FareWellDock meeting

Today, Oct 7 2015, FareWellDock is having its 5th (3rd videoconference) meeting to discuss project progress.

As far as communication is concerned we are doing fine. We now have about 5 scientific papers, 16 conference contributions, 6 farm magazine articles, 1 training, 6 internet contributions (besides the FareWellDock website) and 1 radio performance (see project overview). In addition, the FareWellDock website lists 37 posts. Twelve of these are new since our last meeting in Paris. Also, most partners are present on our partner page.

At the meeting we discuss the report and factsheet for end-users on how to deal with tail biting and tail docking. As part of that discussion we also talk briefly about the HENNOVATION project. In that project a webtool is being developed providing extension information about welfare problems like featherpecking, in a structured and flexible way. It includes the possibility to set up a forum for end-users to discuss innovations, and wiki pages to aggregate collective knowledge (see the Beta version). This is not feasible within the FareWellDock project, but it is good to learn about cross-disciplinary activities.

Videoconference meeting

Videoconference meeting Oct 7, 2015