The effects of changing straw provision on the feeding behaviour and activity of growing pigs given food through single-space feeders

Abstract

AbstractIn a previous experiment the provision of straw to group-housed pigs increased the number of daily feeder visits. This effect of straw is comparable with conditions of reduced social competition for access to the feeder. The aim of this experiment was to investigate if changing straw provision within a pen resulted in similar and reversible effects in this behaviour. One hundred and twenty male pigs (41·1 (s.e. 0·43) kg) were used in three blocks each of four pens of 10 pigs. In each block of 42 days duration one pen had no straw throughout (treatment 1); one pen had no straw for 21 days (period 1) followed by straw for 21 days (period 2) (2); one pen had straw followed by no straw (3) and one pen had straw throughout (4). The pens were situated in a naturally ventilated building with light from 06.00 to 20.00 h. Each pen had a kennel, a lying area and a single-space computerized feeder for recording feeding behaviour. The pigs’ activity was recorded on video in the 2nd and 5th weeks of each block. The number of feeder visits was slightly higher for pigs with straw (1: 9·69 v. 4: 10·46) but this was not significant (P > 0·05). The effect was more marked for treatment 2 where the visits increased (P < 0·01) from period 1 (8·52) to period 2 (10·64) and for treatment 3 where they decreased (11·20 v. 10·10). Pigs without straw (treatment 1) spent more time in the kennel than those with straw (treatment 4) (P < 0·05). For treatment 2 the proportion of time spent in the kennel fell from 0·607 in period 1 to 0·288 in period 2 (P < 0·01). There was a general trend for more activity and more lying outside the kennel when straw was provided. The effect of straw provision was not as marked as that seen previously; nevertheless changing straw provision (treatments 2 and 3) did result in an increase in feeder visits with straw, probably related to the increase in general activity and lying outside in the area adjacent to the feeder.