Sheep slaughter notes

🐑 Types of Animals Processed

• Lamb: young sheep (~8–10 months)

• Mutton: older sheep

Age affects:

• Tenderness

• Flavor

• Value

Older animals → tougher meat → lower value

🧠 Criteria for a Good Slaughter Method

Same principles as beef & pork:

• No cruelty

• Minimize stress

• Rapid, complete bleeding

• Minimal carcass damage

• Must be:

  • Hygienic

  • Economical

  • Safe for workers

🔁 The 8 Major Steps (Red Meat Species)

1. Ante-mortem inspection

2. Stunning

3. Exsanguination (bleeding)

4. Skinning (pelt removal in sheep)

5. Evisceration

6. Post-mortem inspection

7. Final carcass prep

Chilling

1) 🚚 Unloading + Handling (Temple Grandin – Sheep Behavior)

Unique sheep handling trait

• Sheep have a VERY strong following instinct

• Plants use trained leader sheep

  • Leaders guide others off trucks

  • Leaders guide through yards and into plant

This is a low-stress method and improves meat quality.

Handling principles

• Calm handling = better welfare + better meat

• Stress right before stunning → tougher meat

Flooring

• Non-slip flooring is critical

• Sheep tend to run → slipping risk

Driving aids

Often NOT needed:

• Sheep will follow naturally

If needed:

• Plastic bag

• Rattle

• Paddle

Electric prods:

• Rarely used

• Wool acts as an insulator

2) 🏠 Holding Pens (Lairage)

Requirements:

• Must have constant access to water

• If held >24 hours → must be fed

Sheep often:

• Rest

• Chew cud

• Stay calm before slaughter

Grandin note:

• Sheep do NOT know they are going to be slaughtered

• Calm behavior (chewing cud) = relaxed state

3) 🧑‍⚕ Ante-Mortem Inspection

Performed within 24 hours before slaughter by inspector/vet.

Inspectors check:

• Health

• Injury

• Disease

• Fitness for slaughter

Sick/crippled animals:

• Removed

• Slaughtered separately
   

4) ⚡ Stunning (Major Differences for Sheep)

Goal

• Animal must be unconscious before bleeding

MethodsA) Electrical stunning (shown in video)

• Head-to-back electrodes

• Animal is wetted for conductivity

• Current passes through brain → causes:

  • Instant unconsciousness

  • Grand mal seizure

• Back electrode may stop heart

Correct placement is critical:

• Current must pass through brain

Plants audit:

• Stunner placement

• Insensibility checks

Backup method:

• Captive bolt (if electrical fails)

NEVER allow animal to proceed unless fully unconscious.

B) Concussion stunning (lab notes)

Used in small/medium plants:

• Captive bolt pistol

Placement depends on sheep type:

• Hornless sheep → crown of skull

• Horned sheep → midline behind horn ridge

Targets:

• Midbrain

• Brain stem (controls breathing/heart)

5) 🔪 Exsanguination (Bleeding)

While unconscious:

Steps:

1. First knife opens fleece/skin

2. Second clean knife cuts:

   • Carotid arteries

   • Jugular veins

Death occurs from blood loss.

6) 🧥 Skinning (Pelt Removal – VERY Important Difference)

Sheep:

• Do NOT have “hide” like cattle

• Have pelt (skin + wool)

• Valuable for:

  • Leather

  • Wool products

Removal process

Cuts made along:

• Inside of legs

• Belly

Manual removal:

• Workers place hand between pelt & carcass

• Process called “fisting”

Grandin video detail:

• Pelt puller pulls downward

• Keeps dirty wool moving AWAY from meat

• Prevents contamination

Food safety focus:

• Dirty wool = contamination risk

7) 🫁 Evisceration (Organ Removal)

Removed from:

• Back → front (posterior → anterior)

First removed:

• Penis/udder

• Cod/udder fat

Then:

• Bladder

• Uterus (if female)

• Intestines

• Stomach

• Plucks:

  • Heart

  • Lungs

  • Trachea

Important difference:

• Kidneys stay in lamb carcass

• In cattle, kidneys are removed

8) 🔍 Post-Mortem Inspection

Inspector checks:

Head:

• Lymph nodes

• Parasite cysts

Viscera:

• Organs

• Lymph nodes

Carcass:

• Abscesses

• Disease signs

Outcomes:

1. Hold for testing

2. Condemn carcass/organs

3. Pass for food chain

9) 🧼 Final Carcass Preparation

Includes:

• Trimming bruises/clots

• Washing

• Weighing

Antimicrobials may be used:

• Lactic acid

• Acetic acid (vinegar)

• Chlorine

• Bromine

Grandin video:

• Hot water cabinet

• Acid spray for food safety

10) ❄ Chilling

• Carcasses cooled rapidly to reduce bacteria

• First cooler ~0°C

BUT:

• Cooling too fast → cold shortening

• Meat becomes tough

Important note:

• Lamb is VERY prone to cold shortening

• Tough lamb often due to chilling too quickly

11) 🦷 Age Determination (VERY TESTABLE SECTION)

Why age matters

• Older animals = tougher meat

• Lower value

A) Dentition method

Look at lower jaw:

• Lamb:

  • < 2 permanent incisors

• Mutton:

  • ≥ 2 permanent incisors

B) Break vs Spool Joints (Major Exam Topic)

Located in cannon bone (lower limb).

Young animals:

• Cartilage present

• Knife can cut through → Break joint

Older animals:

• Bone ossified

• Must cut at joint → Spool joint

Classification:

• 2 break joints = Lamb

• 1 break + 1 spool = Yearling mutton

• 2 spool joints = Mutton
   

(Shown in bone diagrams on pages 5–6.)

12) 🧾 Definition of a Lamb Carcass (Exam Difference vs Beef/Pork)

Lamb carcass = animal minus:

• Hide

• Head

• Fore + hind legs

• Spinal cord

• Internal organs (EXCEPT kidneys)

• Internal fats

• Cod fat

• Udder fat

Included:

• Kidneys

• Tail

14) 🧠 Behavior-Based Handling (Temple Grandin Key Points)

• Sheep follow leaders naturally

• Solid chute sides prevent distraction

• Visual barrier prevents “visual cliff” fear

• Animals see depth when head lowered

• Small design changes greatly improve movement

15) 🏭 Fabrication + Packaging (Video)

After chilling:

• Carcasses cut into primals

• Vacuum packaged (Cryovac)

• Boxed + shipped

Sanitation practices:

• Disposable plastic aprons

• Strict cleanliness standard