Tying off is the slaughterhouse practice of sealing both ends of an animal’s digestive tract with ties, clips, or knots as it is removed during evisceration. The purpose is strictly hygienic: the gut contains enormous numbers of bacteria, and if its contents spill onto the carcass, the meat is contaminated with faecal organisms including E. coli and Salmonella. By closing the oesophagus and rectum before the tract is cut free, the slaughter team keeps the dirty contents contained. It is one of the critical control points in hygienic slaughter, alongside clean hide removal and rapid chilling. Regulators and auditors watch evisceration technique closely because this single step prevents a major contamination route.