Agriculture Reference
In-Depth Information
of consciousness. (The vertebral artery, being enclosed
in the vertebral column, is not severed in the Jewish or
Muslim method of slaughter.) Anatomical differences in
the blood supply to the brain occur in the various species
of animals. In the sheep and goat, the complete brain is
supplied with blood from the common carotid arteries;
the vertebral arteries supply only the anterior spinal cord
and the posterior medulla oblongata. However, it has
been shown experimentally in calves that the vertebral
arteries can carry enough blood to maintain conscious-
ness when both common carotid arteries are occluded.
Very little blood is required to maintain consciousness,
especially in the head-down position and in young ani-
mals which have a greater resistance to anoxia. It has
been estimated that without stunning, the time between
cutting through the major blood vessels and insensibil-
ity, as deduced from behavioural and brain responses, is
up to 20 seconds in sheep, up to 25 seconds in pigs and
up to 2 minutes in cattle. Some estimates have suggested
that calves can take up to 5 minutes to become insensi-
ble. However, Rosen (2004) in his defence of shechita
argues that the experimental evidence demonstrates
that on severing the carotids, the flow of blood through
the vertebral artery of calves is reversed, away from the
brain, taking the route of least resistance.
A factor of considerable importance is that after the
carotid arteries of cattle are severed transversely, they
tend, by virtue of their elasticity and as a physiological
response to the fall in blood pressure, to retract rapidly
within their own external connective tissue coat, thus
narrowing the arteries and slowing bleeding. As the
blood pressure in the anterior aorta will then be
maintained by the heart action, the blood pressure in
the vertebral artery may likewise be maintained at a
substantial level, and unconsciousness may therefore
be delayed. Such sealing can and does occur, in some
cases very rapidly, and provides an explanation why
some cattle, the throats of which have been cut by the
Jewish method, have been known to regain their feet
and walk a considerable distance before they have
eventually succumbed some minutes later. It is imper-
ative that the slaughterman does not interfere with
the neck in an attempt to ensure a good blood flow in
the period immediately following the cut as this is likely
to cause unnecessary distress and is unlikely to achieve
its objective.
The assertion by supporters of Jewish slaughter that
bleeding of the animal is more complete than in other
methods of slaughter has been challenged by some author-
ities who contend that the paler colour of the flesh of Jewish
slaughtered animals is due to the violent respiratory efforts
which accompany ritual slaughter, these having the effect
of increasing the proportion of oxyhaemoglobin in the
pressure-limiting devices. While the cut is being made,
the hind leg is shackled to withdraw the animal from the
pen. There is no doubt that the Cincinnati-Boss (CB) pen
is much less stressful on the animal than the Weinberg
pen, but it is by no means perfect. One defect is the man-
ner of withdrawal of the animal from the pen, which in
some types of CB pen pulls the hind leg in an unnatural
manner which must result in hip joint damage. Some
stress inevitably occurs due to restraint and raising of the
head. Dunn (1990) compared a rotating Weinberg pen
and the ASPCA pen for slaughter of cattle in the upright
position. He found that the mean time for which the ani-
mal was restrained in the Weinberg pen, from the rear
gate was secure until the throat was cut was 103.8 sec-
onds, of which the animal spent on average 70% (73 sec-
onds) in the inverted position. By contrast, the animal
spent on average 11.1 seconds in the ASPCA pen before
its throat was severed. In addition, the animal struggled
more, especially during inversion and vocalised more,
with the Weinberg than with the ASPCA pen (Fig. 7.12).
A problem with all types of casting pen is that the cat-
tle tend to aspirate blood. This does not occur when the
animal is held in the upright position. It has been
reported that the presence of blood on the equipment
does not appear to upset the cattle and that in fact some
animals have been observed to lick the blood.
Restrainer systems have been manufactured to deal
with
small farm animals
- calves and sheep. In one of
these US items of equipment, which is used for both con-
ventional and religious slaughter, the animal is conveyed
straddlewise along a double rail above which is a head
cage which positions the head upwards for the neck cut.
Many sheep are slaughtered without pre-stunning by
manually restraining them on the floor with their head
lifted or by placing them on their side on a cradle.
It is claimed that the Jewish method of slaughter does
not involve any act of cruelty because the knife is particu-
larly sharp, the cut is made dextrously by a trained person
and the severance of the carotid vessels is followed by a
very rapid fall in blood pressure within the cephalic arter-
ies. It is therefore suggested that the anoxia from the
diminished blood supply to the brain tissues, causing loss
of brain structure, brings about almost immediate uncon-
sciousness. Others contend that it is not anoxia which
results in the collapse of the animal but rather cerebral
shock due to the sudden fall in pressure of the CSF. Gibson
et al.
(2009) carried out histological examination of the
brains from animals slaughtered by ventral neck incision
and found no evidence to support these hypotheses.
Opponents of the Jewish method of slaughter have
also contended that additional blood, via the
vertebral
artery
, and therefore independent of the carotid supply,
may still reach the brain of cattle and prolong the period
