Biotin is a vitamin B group, called B7 or B8 which acts, after binding to lysine, forming biocytin, as a cofactor for various carboxylase involved in the metabolism of fats and amino acids.

Its presence is very important in tissues with rapid mitosis such as intestinal epithelia and skin. Although it may be synthesized by intestinal microorganisms, the combination of low doses of biotin and the routine use of antibiotics in feed may cause real biotin deficiencies manifested by intestinal and plantar lesions.