LAB 4.6 Poultry slaughter method

   Usually poultry are scalded to facilitate the removal of their feathers. The ease with which feathers may be removed is related to the temperature and duration of scalding. However, high temperatures (> 58oC) cause the skin to become dark, sticky and easily invaded by bacteria. Consequently, hard scalding (at 70 to 80oC) is only used for low grade poultry destined for immediate use in processed products. For broilers, the appearance of the skin is unharmed by about thirty seconds of semi-scalding in water at 50 to 54oC. Both temperature and duration are precisely controlled, depending on the age and condition of the birds. After the feathers have been loosened, they are removed by machines that have thousands of rubber fingers mounted on rotating drums. However, many of the strong pin feathers on the tail and wings may survive this treatment and must be removed manually.
   The feathers on the carcasses of ducks and geese are difficult to remove. Following scalding and the mechanical removal of as many feathers as possible, ducks and geese may be quickly dipped in hot wax. After the birds have been removed and cooled, the wax sets hard and can be pulled off together with large numbers of feathers. The wax is melted and recycled, and the birds are picked bare manually.
   Methods for the evisceration of poultry are even more variable than those for meat animals and many of the operations for poultry evisceration have been successfully automated. Poultry usually are suspended on some type of moving overhead rail. Sometimes they are suspended by their feet, sometimes by their heads, and sometimes by both, so that the vent or cloaca bulges downwards. One possible method for the evisceration of poultry is as follows:
 (1) after stunning and exsanguination, the bird is suspended from its head, and the oil gland at the base of the tail is removed,
 (2) an incision is made through the skin along the back of the neck, from the head to the shoulders,
 (3) the crop and the trachea are removed,
, (4) the bird is re‑suspended by its feet, and an incision is made through the skin, around the cloaca and towards the sternum,
 (5) the viscera and the intact cloaca are pulled out and inspected for signs of disease,
(6) the liver is removed and the green gall bladder is discarded, without contaminating the carcass with bile,
(7) the muscular wall of the gizzard is slit open so that the inner lining and the contents can be discarded,
 (8) the heart is removed from the hanging viscera and trimmed,
(9) the remaining viscera are removed and discarded, and the lungs, kidneys and ovary or testes are removed from under the vertebral column with a suction tube,
(10) the head, neck and feet are removed,
(11) the carcass is chilled in a mixture of ice and water,
(12) after chilling, the giblets (neck, gizzard wall, liver and heart) are packed into the carcass.
   Although mass produced poultry are now almost all eviscerated prior to distribution to retail outlets, intact poultry carcasses keep quite well if their viscera are left in place. Growth of intestinal bacteria is minimal below 7oC and, at temperatures below 4oC, uneviscerated carcasses may be stored for at least as long as eviscerated carcasses.