12-15 meters. The enteric coating is a livestock product made from the large and small intestines of domestic animals by scraping, a kilogram of 12-15 meters. Enteric coating is mainly used to fill the outer garment of sausage and enema, sheep enteric coating can also be made into intestinal line for the production of tennis racket line, bowstring and surgical sutures, etc., enteric coating according to the animal division of pig enteric coating, sheep enteric coating and cattle enteric coating, according to the part of the division of the large enteric coating, small enteric coating, intestines from the inside out into the mucous membrane, submucosal, muscular layer and plasma membrane of four layers.