Keeping sows in ideal body condition can be a balancing act. Females that are too thin entering farrowing may have greater stillbirth rates, be more likely to develop shoulder lesions during lactation and have inadequate body reserves at weaning for successful subsequent reproduction. On the other hand, overly fat sows generally incur excessive feed costs and are prone to reduced lactation feed intakes.
Maintaining sows in “ideal” body condition allows farmers to maximize reproduction while optimizing feed costs and animal well-being. Recent publications from North Carolina State University outline sow condition targets to minimize body lesions and maximize productivity.
Figure 1 illustrates associations between sow caliper score at farrowing with the occurrence of shoulder lesions at weaning. These results suggest targeting a sow caliper score of 15 or 16 (high side of “ideal” or low side of “fat”) at farrowing would help to reduce shoulder lesions at weaning, especially open wounds. Figure 2 implies there is a threshold level of backfat at farrowing needed to help minimize shoulder lesions at weaning. Backfat in Figure 2 was measured at the 10th rib. Yet pig farmers commonly measure sow backfat at the last rib, a somewhat leaner measure. Using a conversion from Fitzgerald et al. (2009), 25 mm of 10th rib backfat would equate to 18 mm of last rib backfat.