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 moistur e content was determined from different segments of the equine hoof. 1 10 hoof horn specimens with different pigmentation taken from six adul t warm-blooded horses with no obvious pathological changes within the foot were used for the 177 tension and bending tests which were perfor med in accordance with ASTM D 5026, ASTM D 5023 and DIN 53.457. E-modu li were determined under physiological conditions with mean 761.8, SD +/- 295.4 N/mm for dorsal wall samples, 708 +/- 280.4 N/mm(2) for late ral wall samples, 230 +/- 92.4 N/mm(2) for sole horn and 9.9 +/- 0.6 N /mm(2) for frog horn. Dorsal wall and lateral wall did not differ sign ificantly. E-moduli of the various hoof horn segments differ significa ntly when tested under physiological moisture. The physiological moist ure content also varies significantly between the segments: wall sampl es 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 dryi ng at 65% humidity over 6 days.