Elastic modulus of equine hoof horn, tested in wall samples, sole samples and frog samples at varying levels of moisture.

The study investigates the elastic modulus, or stiffness, of various segments of horse hooves under different levels of moisture. The findings reveal significant differences in the elastic modulus of the hoof samples when exposed to physiological moisture, suggesting that moisture content directly affects the mechanical properties of a horse’s hoof.

Study Overview

• For this research, 110 hoof horn specimens were sourced from six adult warm-blooded horses that had no noticeable pathological changes in their feet.
• The samples were subjected to a series of 177 tension and bending tests following standardized procedures outlined in ASTM D 5026, ASTM D 5023, and DIN 53.457.
• The hoof horn samples were taken from different sections of the horse’s hoof, namely, the dorsal wall, the lateral wall, the sole horn and the frog horn.
• The samples were tested under their natural moisture content, and the elastic modulus of each was determined.

Research Findings

• The elastic modulus values were found to differ significantly across the hoof horn segments when they were tested under physiological moisture conditions. The dorsal wall and lateral wall samples showed no significant difference from each other, but they differed from the sole horn and frog horn samples.
• The mean elastic modulus for the dorsal wall samples was 761.8 N/mm, while for the lateral wall samples it was 708 N/mm. The sole horn showed a significantly lower value of 230 N/mm, and the frog horn had the lowest with 9.9 N/mm.
• In addition to the differences in stiffness, the physiological moisture content also varied significantly across the hoof segments. The walls had a mean moisture content of 22.7%, the sole had 31.5%, and the frog had 34.6%.

Effects of Drying

• In contrast to the differences observed under physiological conditions, the elastic modulus of the various hoof segments approximated to identical values when they were subjected to drying at 65% humidity over 6 days. Similarly, the moisture content of the segments after drying was also approximately the same across all the segments.

Conclusion

• The study demonstrates that environmental moisture plays a critical role in the mechanical properties of horse hooves. This knowledge could be key to understanding and optimizing hoof health and horse performance.