By Mark Knauer, North Carolina State University

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.

Consider the Data

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.

Figure 1. The association between sow caliper score at farrowing with the presence of shoulder lesions at weaning.

Figure 2. The relationship between sow 10th rib backfat at farrowing with the presence of shoulder lesions at weaning.

Figure 3 shows a curvilinear association between sow caliper score at farrowing with piglet survival. A sow caliper score of 15 (high side of “ideal”) maximized piglet survival to weaning. In other data sets, we are commonly seeing similar results. Thin sows appear more susceptible to having stillborn piglets, perhaps more so than overly fat females. Yet overly fat sows also tend to have productivity challenges as well.

Figure 3. Correlation between sow caliper score at farrowing with piglet survival for multiparous crossbred sows.

Based on the current data set, and other studies, our recommendations are to farrow gilts and sows on the high side of “ideal” or low side of “fat” when measuring body condition with the sow caliper. With good lactation management, the majority of these sows should be weaned in “ideal” condition.

Recently, a large genetic company has moved their recommendations for “ideal” to a sow caliper range from 13 to 16 to enhance sow robustness. We applaud this company’s efforts in using big data to make data-driven recommendations to their customers.

Read More:
Parity and Body Condition Score Drive Summer Fertility in Sows

References:
Authement, M. R, and M. T. Knauer. 2023. Associations between sow body condition with subsequent reproductive performance. Open J. Anim. Sci. 13:310-322. https://doi.org/10.4236/ojas.2023.133023

Authement, M. R, and M. T. Knauer. 2023. Associations between sow body lesions with body condition and subsequent reproductive performance. Open J. Vet. Med. 13:111-121. https://doi.org/10.4236/ojvm.2023.137010

Fitzgerald, R. F., K. J. Stalder, P. M. Dixon, A. K. Johnson, L. A. Karriker, and G. F. Jones. 2009. The accuracy and repeatability of sow body condition scoring. Prof. Anim. Sci. 25:415-425. https://doi.org/10.15232/S1080-7446(15)30736-1

Knauer, M. T., and D. J. Baitinger. 2015. The sow body condition caliper. Appl. Eng. Agric. 31:175-178. https://doi.org/10.13031/aea.31.10632

Shike, J. 2022. Parity and body condition score drive summer fertility in sows. Farm Journal’s PORK. Available at: https://www.porkbusiness.com/news/hog-production/parity-and-body-condition-score-drive-summer-fertility-sows