Effect of housing on rubber slat mats during pregnancy on the behaviour and welfare of sows in farrowing crates

The aim of this study was to evaluate the effect of flooring type during gestation, lameness and limb lesion scores on welfare and behaviour of sows in farrowing crates. Sixty sows group-housed during gestation in pens with solid concrete floored feeding stalls and a concrete, fully slatted group area either uncovered (CON; n = 30) or covered with 10 mm thick rubber slat mats (RUB; n = 30) were transferred to the farrowing crate at 110d of gestation (-5d). Lameness was scored on -5d and at weaning (28 d post-farrowing). Limb lesions were scored on -5d, 24 h later (-4d), 3 to 5 days post farrowing and at weaning (i.e., day 28 post farrowing). Sows were video recorded for 24 h on -5d, after the last piglet was born (FARROW) and prior to weaning. Videos were sampled every 10 min and an index of the proportion of time spent in different postures (standing [S], ventral [VL] and lateral lying [LL] and total lying) and number of postural changes was calculated. Median scores were calculated for limb lesions and classified as <= median or > median. Postural data were tested for normality and analysed using mixed model equations methodology. Flooring during gestation did not affect any of the variables recorded in this study. However, RUB sows tended to make more postural changes than CON sows (P = 0.10). Sows with swelling scores > median spent more time LL (68.9 vs. 63.1 +/- 2.19%; P < 0.05) and less time VL (19.9 vs. 25.8 +/- 2.27%; P < 0.05) than sows with swelling scores <= median. Time spent S and VL decreased and LL increased at FARROW compared to -5d and prior to weaning (P < 0.01). We found no effect of flooring type during gestation on welfare and behaviour in the farrowing crate. Factors such as limb lesions and adaptation to confinement (i.e., time spent inside the farrowing crate) appeared to have a greater influence on sow welfare and behaviour in farrowing crates than the flooring on which they were housed during gestation.