Effect of a dietary supplement of biotin on pig hoof horn strength and hardness.

Supplementary biotin (1 mg d-biotin/kg feed) increased the compressive strength of the mid-abaxial sidewall region of pig's hoof from 9.3 (+/- 0.5) X 10(6) N/m2 to 12.0 (+/- 0.5) X 10(6) N/m2 (P less than 0.05). It also increased the hardness of this region, measured on the Shore A and D hardness scales (P less than 0.05). The leading edge of the hoof wall was significantly stronger than the sidewall (P less than 0.001) with a compressive strength of 14.5 (+/- 0.7) X 10(6) N/m2. This site showed no significant improvement in compressive strength or hardness in response to biotin. Biotin also produced a significant decrease in the hardness of the heel bulb on the Shore A scale (P less than 0.05). There would therefore appear to be a rational biomechanical basis for the finding by others that biotin reduces lameness. The Shore A and D hardness testers are sensitive to the improvement produced by biotin and may be useful as small, hand-held hoof testing devices for use in field conditions by the practising veterinarian.