Bleeding is the part of the slaughter process where the main blood vessels of the neck are severed in order to allow blood to drain from the carcass, resulting in the death of the animal from cerebral anoxia. The bleeding knife should continuously be sharpened. A blunt knife will prolong the incision and the cut ends of the blood vessels will be damaged. This may cause premature clotting and blockage of the vessels, delaying bleeding out and prolonging the onset of unconsciousness and insensitivity. Incisions should be swift and precise. In poultry, sheep, goats and ostriches, the throat is cut behind the jaw .
The standard method for the bleeding of cattle is to open the skin at the neck between brisket and jaw through a 30-cm longitudinal cut. Then, for hygienic reasons, a clean knife should be used and inserted at a 45° angle in order to sever the jugular and carotid vessels.
In pigs, a longitudinal bleeding stick is made into the chest to sever the deep vessels.
For all cuts, the jugular and carotid vessels should be completely severed. If all vessels are not cut, bleeding may be incomplete, causing excessive retention of blood in the tissue, which can result in early spoilage of meat.
A minimum of delay is required between stunning and bleeding for two reasons:
a. A prolonged delay in bleeding may result in a level of consciousness being regained particularly where animals have been stunned electrically. For example, poultry stunned electrically may regain consciousness within 1-3 minutes. Generally, bleeding of poultry should commence within 15 seconds of stunning. For other livestock, the interval between stunning and sticking/bleeding should also be kept very short. Periods of less than one minute are desirable.b. Delayed bleeding will result in an increase of blood pressure, and blood vessels will rupture, causing muscle haemorrhage. This extra blood in the tissue will cause the meat to decompose more quickly, resulting in waste of meat.