Agriculture Reference
In-Depth Information
Figure 8.4
Downward hide-puller; more hygienic than upward puller and can also skin head, previously prepared.
from the carcase and head. These flecks must be removed
immediately by trimming. Work by Madden, Murray
and Gilmour (2004) in Northern Ireland indicated that
hide-pulling was the major point of bacterial contamina-
tion of beef carcases and hence an important potential
intervention stage for controlling the final microbiologi-
cal quality of the carcases (Fig. 8.4).
A particularly important initial cut through the skin is
the one which exposes the major vessels in the neck for
sticking. As previously described, the knife contaminated
while incising the skin must be washed and sterilised, and
a clean knife used to sever the blood vessels.
mechanically removed. This dust can be virtually impos-
sible to remove from the carcase surface. Pelting
machines which allow the pelt to flap about and recoil
excessively when it is released from the carcase are most
likely to result in the exposed meat surface being show-
ered with loose hairs and other debris from the fleece.
In the
traditional sheep dressing system
, the lamb was
suspended initially by the hindlegs. The pelt was freed
manually from the hind-quarters and removed to the
level of the shoulders by a combination of 'punching
out' and pulling downwards from tail to head. The
forelegs were then lifted and hung on a rail running
parallel to that suspending the hind-feet, and the fore-
quarter was skinned using knife work and a horizontal
pull. This technique has been replaced in many sheep
slaughter lines by a more hygienic system, known as
inverted dressing
. The lamb is suspended initially by
the forelegs, and the pelt is loosened from around the
shoulders. Some knife work is utilised to partially free
the pelt from the hindquarters, before it is removed by
a mechanical pelter pulling from head to tail. Gill
et al.
(2000) studied the microbiological difference between
carcases dressed conventionally and by the inverted
method and found the latter to be 1.5 log units less
coliforms or
E. coli
.
Sheep
Most of the techniques described for cattle are also
applicable to sheep. Adequate spacing on the line is
particularly important when dressing sheep. Many of the
problems occur with the ventral incision and with
in-rolling of the fleece. Again the elasticised crocodile clips
are useful. Judicious use of glossy paper sheets placed on
the sternum and inguinal regions can be very successful. It
is imperative that the right sort of paper, which will remain
in place but not adhere permanently to the carcase, is used.
A particular problem may be encountered where
dry, dirty sheep release dust while the fleece is being
