Impressions of sow overgrown toes on U.S. farms: What environmental factors are driving this?

  • Derek Henningsen (ISU)
  • Jennifer Bundy (Iowa State University)
  • Anna K. Johnson (Iowa State University)
  • Kenneth J Stalder (Iowa State University)
  • Marta Mainenti
  • Locke A. Karriker (Iowa State University)


The purpose of this study was to poll farm managers regarding (1) prevalence of sow overgrown toes at their farm, and (2) to determine if environmental factors were a driving factor behind prevalence of overgrown toes. All survey questions were self-reported by the participants. There was a total of 20 questions, which were separated into 6 different categories: farm demographics, flooring, sow characteristics, lameness, incidence of overgrown toes, and removal reason. The top 20 swine producing companies were chosen as potential survey participants by utilizing the Successful Farming Exclusive: Top 40 U.S. Pork Powerhouse List of 2020.Survey questions regarding overgrown toe percentage will be presented descriptively as tallies and percentages. For environmental factors, four models were created using overgrown toe percentage as the dependent variable. A variable was deemed significant if the P-value was ≤0.05. The survey was open for 72 d (May 20, 2022, to July 29, 2022). Surveys were considered “complete” if greater than 80 % of the questions were answered. A total of 63 surveys (that encompassed 275,000 gilts and sows) were completed. When parceling out the percentage of overgrown toes on-farm, half of the participants ranked the prevalence as low (≤5%) and only 6% of respondents reported overgrown toe percentages greater than 15%. There were no observed correlations between housing type, flooring type, or flooring condition and the percentage of overgrown toes (P≥0.36). There was an observed significant correlation between lameness reason and percentage of overgrown toes (P =0.0017). This study provided no evidence that housing type, flooring type or flooring condition contributed to increased instances of overgrown toes potentially suggesting an alternative causation for the toe overgrowth

Keywords: Long toe, Swine, Welfare

How to Cite:

Henningsen, D., Bundy, J., Johnson, A. K., Stalder, K. J., Mainenti, M. & Karriker, L. A., (2024) “Impressions of sow overgrown toes on U.S. farms: What environmental factors are driving this?”, Iowa State University Animal Industry Report 20(1). doi: https://doi.org/10.31274/air.16937

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Published on
01 Apr 2024
Peer Reviewed
Public Domain