Hoof horn, which forms the capsule at the lower part of the legs of many grazing animals including equids (horses, donkeys and mules), is a composite natural material based on a-keratin; Its function is influenced by the tubular and intertubular material and is modulated by the moisture content. There is a requirement to adopt a standard approach to drying regimes and sampling protocols in order to make progress in understanding how the biomechanical properties of hoof horn a re related to its structure. In th is work the stiffness of donkey hoof has been examined using a three point bending technique and the effect of hydration has been investigated. Also the tubule density properties of this hoof horn material are reported.