LAB 4.6 Poultry slaughter method
PLAY VIDEO
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.