Meat&Poultry - June 2013 - 74

From the Corral
BY DR. TEMPLE GRANDIN
meatpoultry@sosland.com

STUNNING evidence
and the amperage varies. The ques-

ic and clonic phase. The animal will

tion that has been asked is: ‘Are volt-

remain insensible if the heart stun is

age-regulated units humane?’

applied before the clonic (paddling

The bottom line is: regardless of

phase) stops. This will solve humane

circuit design, an electric stunner must

concerns about conducting this test.

produce an epileptic seizure. I have

Failure to do this test would result in

observed stunners with fake amperage

thousands of animals that may not be

meters. There are also units available

rendered insensible.

that change the frequency of the cur-

In many larger plants, simultane-

here have been many questions

rent to prevent blood-splash damage

ous head-to-body stunning is used,

about the best way to determine

in the meat. Higher frequencies re-

where a current is passed through

if animals have been rendered insen-

duce meat damage, but too high of a

both the brain and the heart at the

sible by electric stunning. If the ani-

frequency will fail to induce a seizure.

same time. Many of these units use

mal has a true natural blink, it is not

Since it is impossible for all plant per-

proprietary amperage-regulated and

stunned correctly. A natural blink oc-

sonnel to become electrical engineers,

frequency-regulated circuits. In most

curs when the eye makes a complete

when I audit a plant I look for clinical

larger plants, the stunner is applied for

cycle of opening and closing. To test

signs that the stunner is actually cre-

two to three seconds. The short time

for a natural blink, wave your hand

ating an epileptic seizure with a ton-

makes it possible to see signs of a weak

a few inches from the eye. A natural

ic (rigid) phase and clonic (kicking,

tonic and clonic phase. The clinical

blink will look like a live animal in

paddling) phase.

signs of the seizure are partially at-

T

the stockyard.

tenuated (reduced) by body stun. If

Proper stunning

I can observe a weak rigid and clonic

stunning must induce a grand mal epi-

When an animal is correctly stunned

phase, I know the stunner is working

leptic seizure. Failure to induce a sei-

for one to three seconds with a revers-

and inducing instantaneous insensi-

zure will result in an animal that may

ible head-only stun, a clear tonic and

bility in the animal.

be paralyzed and sensible to pain. In

clonic phase of the seizure can be ob-

The trend in animal welfare is to

many countries, both regulations and

served. If the stunner is held on for 30

use animal-based outcome measures.

guidelines state that a minimum of

seconds, the spine will become depo-

The OIE and American Meat Insti-

1.25 amps must be passed through the

larized and the seizure will not be ob-

tute’s minimum settings are a mini-

brain. The original studies were done

served. This animal will be insensible

mum baseline, but I do not fully trust

on small, 100-kg (220-lb.) pigs. The

provided that the stunner was capable

the meters because I have seen too

larger pigs that are being processed

of producing a seizure when applied

many fake things. It is also not possible

today will often require a greater am-

for one to three seconds.

to safely train auditors and inspectors

Research clearly shows that electric

When cardiac arrest stunning is

to open up electrical equipment and

The best electric stunners use an

used, the signs of a seizure are difficult

test it. To ensure humane slaughter,

amperage-regulated circuit. The de-

to observe. Stopping the heart masks

looking at a meter is not sufficient to

sired amperage is set and voltage var-

the signs of a seizure. If a sequential

determine if electrical stunning is cre-

ies. In the US and other countries,

stun is used where the current is ap-

ating instantaneous insensibility. An

there are older, voltage-regulated units

plied to the head fi rst and then a sec-

inspector or auditor needs to see signs

being used. In very small US plants,

ond current is applied to the heart, it

of a seizure. ■

these units are popular because they

is easy to determine that the stunner

are much less expensive. With this

is working by delaying the heart stun

type of unit, the desired voltage is set

for a few seconds to observe the ton-

perage setting.

74

• Meat&Poultry • June 2013 • www.MeatPoultry.com

Dr. Temple Grandin operates Grandin Livestock
Systems Inc., Fort Collins, Colo., and is a faculty
member at Colorado State Univ.
http://www.MeatPoultry.com
Meat&Poultry - June 2013

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