The lack of biotin can be primary, because of low levels in food, or secondary because of a suspension of its absorption proceeding from presence of antibiotics or mycotoxins (especially tricótesenos) in food.

Whatever is a reason, in birds are presented as an insufficient mucous membranes and an epithelium which are shown first of all in injuries, loss of integrity of a mucous membrane of a digestive tract and bad plumage.

Necropsy allows to observe, at the intestinal level the cross cracking of a mucous membrane and presence of gelatin made by remains of a mucous membrane and blood as it can be observed in the enclosed photos.

Zoo technical consequences are reduction of growth in broilers and falling of blossoming in fertile eggs in the reproducing birds.