Why a simple caliper measurement might help keep more productive sows in your herd.
Sow body condition is nothing new to experienced producers—but a recent study shows that how we measure and manage that condition might have more impact than we realized.
At the ASAS Midwest meeting, PIC presented data from over 37,000 sows across production systems in the U.S. and Brazil, focusing on one specific tool: the sow body caliper. The goal? To see how caliper measurements taken around farrowing relate to sow productivity and whether those sows stay in the herd longer.
Here’s what they found—and why it matters for your farm.
What’s the caliper and how is it used?
The sow caliper is a tool that quickly and consistently estimates sow body condition at key moments: right before farrowing and at weaning. Think of it as a numeric version of “eyeballing” the sow’s body—standardized into units. PIC currently recommends the range of 13-16 caliper units as ‘ideal’.
By comparing caliper values before and after lactation, the researchers also measured body condition loss during lactation—a key signal of how well a sow is coping with the demands of feeding a litter.
The sweet spot: Not too much, not too little
The study showed a curved relationship between caliper values and sow outcomes. That means both low and high caliper readings were linked to poorer results. The best performance came from sows in that ideal 13–16-unit range.
- Too lean? Sows with less than 9 caliper units before farrowing had 4.4 times higher risk of mortality and were more likely to be removed from the herd, especially due to prolapses.
- Too fat? Sows with high caliper values (>15) had lower feed intake during lactation and lost more body condition, putting them at risk in the next cycle too, especially on reproductive losses.
Caliper loss during lactation matters.
One of the most useful insights was how much body condition sows lost during lactation:
- Sows that lost five or more units were 2.4 times more likely to be culled in the next cycle.
- Even losing 3–4 units significantly increased the removal risk.
This tells us that caliper change = risk signal. It’s not just about how a sow starts lactation—it’s about how she holds up during it.
What does this mean for producers?
Whether you’re a small family farm or managing thousands of sows, this research highlights some simple takeaways:
- Start measuring consistently. A caliper gives you a standardized way to assess body condition—not just by eye.
- Watch for large losses. Big drops in caliper from farrowing to weaning may signal a sow is at risk and needs attention.
- Avoid extremes. Both thin and over-conditioned sows had worse outcomes. Keep most sows in that 13-16 range.
- Think beyond today. The real value is in knowing which sows are likely to stay in the herd longer—and produce more litters over time.
Bottom line
Sow condition isn’t just about appearance—it’s about performance, survival, and profit. With a simple caliper tool and a close eye on changes from farrowing to weaning, producers can make smarter, data-driven decisions that protect both sow welfare and the bottom line.
At PIC, we believe that better data leads to better pigs—and longer-lasting, more productive sows. Never Stop Improving.
For further information please reach out to your contact at PIC.
