The effects of the gestation and farrowing environments on sow and piglet behaviour and piglet survival and growth in early lactation

The effects of gestation (individual stall vs. group pen) and farrowing/lactation (conventional crate vs. prototype pair-pen system for two sows) treatments on sow and piglet behaviours considered relevant to piglet survival were examined in a 2 X 2 factorial experiment involving 96 primiparous crossbred (Large White X Landrace) sows and their litters. The pair-pen system provided each sow with an area of about 10 m(2) and included a specific farrowing area which contained features important for piglet survival similar to those found in farrowing crates, i.e. small area and heated creep. Sow and piglet behaviour and piglet survival and growth were measured to Day 8 of lactation. While a greater (P < 0.01) proportion of piglets were alive on Day 8 for sows in the gestation stall treatment compared with the gestation pen treatment (88.6 vs. 83.3% of total born (TB)), mean litter size at birth tended to be smaller (P < 0.1) in the former treatment (8.6 vs. 9.4 piglets per sow). Piglet mortality was higher for sows housed in group pens during gestation and crates during farrowing than for sows in the other treatment combinations. Stillbirths occurred at a rate of 8.4 vs. 4.4% of TB and deaths of liveborn piglets in the first 3 days occurred at a rate of 11.0 vs. 6.1% of TB in the gestation pen-farrowing crate treatment compared with the other treatments combined. Sows in the crate treatment compared with those in the pair-pen treatment directed less behaviour to their piglets (e.g. investigation of piglets: Day 1, 7.2 vs. 10.0% of observations, P < 0.01; vocalisation to piglets: Day 1, 9.0 vs. 12.2% of observations, P < 0.05) and were less responsive while feeding at the trough to the loud vocalisations of one of their piglets (e.g. 57 vs. 89% of sows at Day 3 in the crate vs. pair-pen treatments stopped feeding in response to the piglet's vocalisations, P < 0.05). The results suggest that the gestation environment had only minimal, or at most short-term, effects on the behaviour of sows and piglets in early lactation. In contrast the farrowing environment had marked effects, particularly on sow behaviour. The present experiment demonstrates that modifying the farrowing environment affected maternal behaviour in sows. However, there is little evidence to support the hypothesis that increased maternal behaviour was associated with improved piglet survival.