Data from the Zinpro® large-scale claw scoring analysis reveal that claw lesions are more than a welfare concern. Lesion severity is closely linked to sow performance and longevity, underscoring the critical role of early intervention in maintaining productive, profitable herds.
Claw lesions in sows have long been recognized as a welfare concern, often linked to lameness and early culling. What has been less well understood is how closely claw health is connected to reproductive performance and whether those observations could be turned into a practical on-farm tool.
By analyzing claw health and production data from more than 6,000 sows across commercial herds, Zinpro® researchers have developed the Zinpro® Sow Excellence Index, a claw health index that does more than describe lesions: it helps predict reproductive outcomes and productive longevity, moving claw assessment from observation to decision-making criteria.
Using clustering analysis, sows naturally separated into two groups:
Multiple claw lesions were combined into a single composite measurement, known as the L-index. Lower values indicate better overall claw quality, while higher values reflect more severe lesions. When L-index scores were analysed alongside reproductive key performance indicators, clear patterns emerged:
- Sows with poor claw health and lower reproductive performance.
- Sows with good claw health and stronger outcomes.
Sows with higher L-index scores consistently produced fewer liveborn piglets and had higher stillbirth rates. Although sows in both groups could initially reach similar production levels, sows with poor claw health tended to peak earlier and decline faster, while sows with better claw health maintained performance for longer.
Parity played a key role in claw condition. L-index scores increased with age, with older sows (parities 4–6) showing significantly worse claw health than younger animals. Heel overgrowth and erosion increased with parity indicating mechanical wear, while white line lesions decreased over time, likely indicating the culling of sows suffering from these painful, inflammatory lesions.
The message for producers is clear: claw health is an indicator of sow performance, and the earlier problems are addressed, the greater the opportunity to protect lifetime productivity and return on investment.
Farrowing Performance by Sow Groups

Figure 1: Farrowing Performance by Sow Groups – Born Alive

Figure 2: Farrowing Performance by Sow Groups – Stillbirth Rate
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