Relationships among gilt and sow live weight, P2 backfat depth, and culling rates

To examine a high culling rate problem, data were collected on 2154 sows culled from a commercial 5400-sow farrow-tofinish unit in New South Wales, Australia, during a 12-month period. Data recorded were parity, body weight, P2 backfat depth, and reason for culling. Additionally, body weights and backfat depths were recorded for a cross-section of the herd (3378 sows) in order to provide control sows for comparison. Reasons for culling were 63.7% for reproductive inefficiency or failure, while a further 12% were due to locomotor problems. Of females culled for reproductive reasons, 42.2% were gilts, indicating gilt management to be a major contributor to the high culling rate. When adjusted for parity, season, and day relative to weaning, culls had lower body weights (P < .05) and less backfat depth (P < .001) than controls (209.7 versus 211.4 kg and 14.8 versus 15.3 mm for culls and controls, respectively). These data suggest that inadequate sow nutrition was a contributor to the high culling rates, although the main problem was gilt management. Studies are ongoing to determine effects on retention of increased backfat and body mass of gilts at breeding and of providing increased dietary protein to younger sows.