Annex A - Species-Specific Stunning Guidelines - Red Meat Species
3. Sheep, Lambs, Goats

3.1 Mechanical

Important factors:

  • Handling and restraint facilities must meet current OIE and industry standards.
  • There is a marked variation between the thickness of the skulls of horned and hornless animals.
  • Horned animals, especially mature males, have very thick frontal bones.
  • Know the approximate location of the brain in the skull.
  • Use the appropriate landmarks. (See below.)
  • Plan the trajectory so the bolt or projectile travels through the following parts of the brain (cerebral hemispheres, midbrain, brainstem). Of these the midbrain and brainstem are the most important. They are located in the centre of the cranium at the level of the attachment of both ears. (See [e] below.)

3.1.1 Landmarks and approaches

3.1.1.1 Hornless

Hold and discharge the mechanical stunning device so that the bolt/bullet enters the top of the skull at the midpoint of an imaginary line drawn between the animal's ears (See [a], [b] and [c] below.)

[a]
imaginary line drawn between the animal's ears - side view
[b]
imaginary line drawn between the animal's ears - front view
[c]
imaginary line drawn between the animal's ears - top view
Legend - stunning for hornless sheep
ImageDescription
line connecting the base of the two ears Line connecting the base of the two ears. The midpoint of this line indicates the location of the brainstem in the middle of the skull.
line connecting the base of the two ears Trajectory of the projectile as it travels to the midbrain and brainstem.

3.1.1.2 Horned

  • Horned sheep and goats must be stunned from the top of the head (see 3.1.1.1 Hornless for landmarks), unless the presence of horns prevents the use of this approach (see [c], [d], [e] and [f] for the top of the head approach).
  • If the configuration of the horns make it necessary to stun from poll position, discharge the mechanical stunning device so that the bolt/bullet enters the skull just behind the midpoint of the nuchal crest and is directed towards the animal's mouth. (See [g].)
  • Stunning in the poll position (just behind the horns or on the nuchal crest) can result in a rapid recovery of consciousness. Therefore, bleeding must be commenced within 15 seconds by cutting both carotid arteries, or the vessels from which they originate. (See [g].)
[d]
horned goat - front view with arrow pointing to stun site
[e]
horned goat - side view with arrow pointing to stun site
[f]
horned sheep - side view with arrow pointing to stun site
[g]
horned goat - side view with arrow pointing between horns
Legend - stunning for horned sheep
ImageDescription
location of the brainstem and midbrain Location of the brainstem and midbrain - in the middle of the skull.
trajectory of the projectile Trajectory of the projectile as it travels to the midbrain and brainstem.
trajectory of the projectile Trajectory of the projectile as it travels to the midbrain and brainstem.

3.1.2 Mechanical Stunning Devices

3.1.2.1 Captive Bolt

  • Use the manufacturer's recommended charge, cleaning, maintenance and stunning protocols.
  • Use 4 ¾ in. bolt. A shorter bolt may be used on small lambs.
  • Bolt velocity and charge must be appropriate to the species, animal size and the presence or absence of horns.
  • Assess bolt velocity daily by using the manufacturer's bolt velocity testing device, or similar means.

3.1.2.2 Firearms

Use the slowest velocity and minimum energy required to effectively stun the animal. (See below).

Firearms for slowest velocity and minimum energy required to effectively stun the animal
Stunning DeviceHornlessHorned
Captive Bolt Small charge Appropriate charge
Firearm .22STable Note 1 is sufficient .22 LRTable Note 2

Table Notes

Table Note 1

.22 short

Return to table note 1 referrer

Table Note 2

22 long rifle Do not use hollow point cartridges.

Return to table note 2 referrer

Ammunition
ammunition

3.2 Electrical

Important factors:

  • Handling and restraint facilities must meet current OIE and industry standards.
  • Sheep can be the most difficult animals to stun electrically - due to the resistance of wool.
  • Mature large animals have greater resistance to the flow of electrical current through their body; therefore, greater amperage and voltage must be used to effectively stun them. (See below).

3.2.1 Landmarks and approaches

3.2.1.1 Head-Only

  • Electrodes must be placed over each temple (between the eye and ear) to span the brain.
  • Placing the electrodes over the occipital condyles (behind the ears) is not effective with head-only stunning.
  • Electrodes must be designed to facilitate penetrating the wool and making good contact with the animal's head.
  • Electrodes and contact location must be wet (or water flow) to facilitate conduction of the electrical current.
  • Current must flow for 3 seconds.
  • The animal must be stuck within 15 seconds as recovery from head-only stunning is rapid.

3.2.1.2 Head-to-Body

  • Head-to-body stunning is far more effective than head-only stunning (head to body is preferred).
  • Electrodes must be designed to facilitate penetrating the wool and making good contact with the animal's head.
  • Electrodes and contact location must be wet (or water flow) to facilitate conduction of the electrical current
  • Current must flow for 3 seconds
  • The head and back (body) electrodes are placed 25 to 40 cm (10 in.-16 in.) apart.
  • Options include:
    1. Place two contacts on top of the head (between the ears) with a third contact placed over the spine.
    2. Place one contact on each side of the head (spanning the temples) with a third "saddle" contact placed over the spine. (Note: using the condyles is far less effective than the temple area)
    3. Place one contact on top of the head with a second contact made over the left chest (arm pit).
Minimal Electrical Stunning Parameters for Sheep, Lambs and Goats
AnimalAmperageVoltsFrequencyTime (sec)
Lambs (shorn) and kids 0.6 250-350 50-60 3
Sheep and goats 1.0 300-400 50-60 3

3.3 Gas, Gas Mixture

These are not commonly used to stun sheep as the wool absorbs a lot of gas, making the system very inefficient.

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