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

The elastic (E-) modulus of hoof horn samples as a function of moisture content was determined from different segments of the equine hoof. 110 hoof horn specimens with different pigmentation taken from six adult warm-blooded horses with no obvious pathological changes within t he foot were used for the 177 tension and bending tests which were performed in accordance with ASTM D 5026, ASTM D 5023 and DIN 53.457. E-moduli were determined under physiological conditions with mean 761.8, SD +/- 295.4 N/mm for dorsal wall samples, 708 +/- 280.4 N/mm2 for lateral wall samples, 230 +/- 92.4 N/mm2 for sole horn and 9.9 +/- 0.6 N/mm2 for frog horn. Dorsal wall and lateral wall did not differ significantly. E-moduli of the various hoof horn segments differ significantly when tested under physiological moisture. The physiological moisture content also varies significantly between the segments: wall samples mean 22.7 +/- SD 3.4%, sole samples 31.5 +/- 3.1%, frog samples 34.6 +/- 3.3%. In contrast, the E-moduli and the moisture contents of the various segments were approximately identical, when tested after drying at 65% humidity over 6 days.