A comparison of the behaviour and performance of sows and piglets in crates and oval pens

A comparison was made of sow lying behaviour, piglet aggregation behaviour and performance in crates (no. = 10) and oval pens (no. = 8). Twenty-four hour time-lapse video tapes were made and a farrowing day defined for each sow by noting the 24-h period during which the sow gave birth (09:00 to 09:00 h). Each sow and litter, balanced for parity and time of year, was analysed from 12:00 to 20:00 h during the 24 h immediately following this day. The following analyses were conducted: (1) the number and type of lying behaviour; (2) each litter was scanned every 10 min and at each lying event the number of piglets within 0.3 m of the sow noted two indices were then calculated, based on the mean of the 10-min scans and the mean for the lying events, for each sow expressed as a proportion of the total litter size. Any dead piglets were removed and cause of mortality established by post-mortem examination. Production data showed that there was no significant difference between litter size at birth and at weaning but overall level of mortality was higher in the pen compared with the crate due to crushing. The majority of crushing events occurred in the first 3 days after farrowing (crate 75%; oval pen 64%). The total number of lying events and related posture changes did not differ between systems; only 'roll-over' events (movement from lateral on one side to the of her within 10 s) were higher in the oval pen. There was no difference in the proportion of aggregating piglets at the 10-min scans or the lying events. Increased crushing mortality in the pen does not appear to be due to the aggregation behaviour of piglets but to the increased number of sow roll-over behaviours.