Behavioural patterns and reproductive performances of sows housed in dynamic groups with slatted flooring and straw bedding during the pregnancy phase

Two pens for 100 pregnant sows in a dynamic group are compared. Each pen is provided with 3 electronicfeeding stations. In the rest areas of the two pens different types of flooring are used: totally slatted flooring (A) and deep straw bedding (B). Reproductive data have been recorded for about 96 multiparous sows housed in both pens A and B for two pregnancy periods in succession. The comparison between pen A and pen B shows significant differences in number of piglets born alive per litter. Sows housed in pen A during gestation average 11.57 piglets born alive versus 10.68 averaged by the same sows housed in pen B (P < 0.05). The study shows differences in the behaviour of sows in the two groups. Whilst there are no differences in the total periods spent resting (71% for group A, 72% for group B), the deep straw bedding promotes a greater sense of welfare in the sows: they are quieter and less aggressive in the feeding area. Straw bedding in rest area of pens for pregnant sows affects animal welfare in different ways; although straw reduces aggressive behaviour in sows, it may cause productivity reduction and higher mortality of piglets before birth.