ANSC*2340: Beef Slaughter

Excel’s production process

Can be divided up into two areas: slaughter and fabrication.

ideal beef cow live weight

600 to 900 kg.

dressing percent

The percentage of carcass weight when compared to live weight.

cows killed per day

4,000-5,000 beef cattle.

good slaughter method

1. Animals must not be treated cruelly.

2. Animals must not be unnecessarily stressed.

3. Exsanguination must be as rapid and as complete as possible.

4. Damage to the carcass must be minimal, and the method of slaughter must be:

   1. Hygienic

   2. Economical

   3. Safe for abattoir workers

slaughter of red meat species steps

1. Ante-mortem inspection

2. Stunning

3. Exsanguination (sticking or bleeding)

4. Skinning (removal of hide/pelt for cattle and lambs/sheep respectively vs dehairing of pigs)

5. Eviseration (removal of guts)

6. Post-mortem inspection

7. Final carcass preparation

8. Chilling

ante-mortem inspection

Conducted by a vet or under direction of a met by a meat inspector. Performed within 24 hours prior to slaughter (death of an animal) - inspection of a LIVE animal.

Examining to determine whether a given animal is fit to be slaughtered → both animal welfare and food safety/human health basis.

Sick or crippled animals are separated from the group for special attention. Meat from animals that are obviously sick or exhibiting abnormal behaviour will not be allowed to enter the human food chain. These animals are euthanized and do not go through the slaughter process.

Look for: crippled animals, animals with signs of fever or CNS disease, zoonoses (e.g. Mad Cow Disease or Bovine Spongiform Encephalopathy), if drug withdrawal times met, hormone implants, excessive amounts of tag (hides covered with dirt + manure → pathogens).

stunning

Humane slaughter methods are followed. Animal should feel no pain when slaughtered.

Animal must be rendered unconscious and insensible before exsanguination. Goal: effective stun → immediate insensibility to pain.

Most common in North America: concussion stunning → applied to specific location on the head for maximum concussion and maximum penetration of the brain.

Small operations: hand-operated captive-bolt pistols with a 0.22 blank cartridge.

Large abattoirs: pneumatic concussion stunning systems.

exsanguination

While unconscious, a sticking knife is used to open the thick hide at the base of the cow’s neck. A second, clean knife is used to penetrate the clean tissues under the hide and to sever the major blood vessels from the heart to the head.

Targeted blood vessels: carotid artery and jugular vein (severing these will cause death).

skinning

Most beef hides are used for leather production. Thus, they must not be damaged by cuts as the hide is removed from the carcass.

Cuts made along the medial faces of the limb and along the animal’s belly to facilitate removal of whole hides with as little loss as possible.

Large abattoirs: may have a hide puller.

Small abattoirs: may use an air knife.

On-farm slaughter: may use a skinning knife (lengthy process).

evisceration

Viscera are removed starting from posterior to anterior.

Starts in abdominal cavity, finishes in thoracic cavity.

First to be removed = udder or penis + any cod fat in region between hindlimbs.

Opening allows removal of bladder and uterus, then large and small intestines. Next is removal of anus and rectum (done with great care, must be closed off with a plastic bag to prevent fecal contamination).

Esophagus is tied off at the other end of the gut to prevent contamination of the throat of the carcass from gut contents leaking out.

Rumen is removed, then liver and diaphragm (must be cut away from rib cage); muscular part of diaphragm remains on carcass (edible red meat).

Lungs, hearts, and trachea are removed together.

bunging

Closing off the anus and rectum before their removal to prevent fecal contamination of the carcass.

plucks

Lungs, heart, and trachea. Removed together at the end of the evisceration process.

post-mortem inspection

A search for parasites, infected lymph nodes, and signs of disease on the carcass, along with examining the viscera that have been removed from the carcass.

If abnormalities or disease present, inspector must make a decision.

1. Hold carcass for further testing. May require trimming of the carcass or condemning specific organs.

2. Condemning the carcass and associated organs → will have to be destroyed or sent for rendering.

3. Allow carcass to enter human food chain.

Inspection of the head, viscera, and carcass.

Head: inspect retropharyngeal, submandibular, and parotid lymph nodes; inspect for presence of cysts in muscles (indicative of tapeworm infestation); palpate tongue.

Viscera: examine major organs + lymph nodes in the thoracic and abdominal viscera; key organs and tissues to be inspected are usually spread out on a large tray.

Carcass: check for abscesses in the muscle and along the spine.

final carcass preparation

Includes trimming and removal (blood clots, bruises, tags, etc.), washing and weighing.

Wash: antimicrobial such as lactic acid, acetic acid, chlorine, bromine, and others. May also incorporate hot water or steam pasteurization.

chilling

Meat is never frozen straight off the kill floor. Must be cooled as rapidly as possible to reduce surface microbial growth.

First meat cooler = 0 degrees Celsius, high air speed, high humidity.

A day after slaughter, carcasses moved to a less severe environment (less air movement to avoid drying carcass and less humidity to discourage mold growth).

Beef: carcass should not get below 10 degrees Celsius within 10 hours of slaughter.

Usually chilled for 48 hrs before carcass is broken down.

spray chilling

Some plants use cold water to spray on carcasses to accelerate carcass chilling. Reduces cooler shrink.

cold shortening

Carcass must not be cooled too rapidly pr else the muscle fibres will shorten and the meat will become very tough.

composition of a steer

• 60.0% carcass

• 10.0% fill (gut contents, etc.)

• 7.3% hide

• 7.2% inedible organs

• 6.0% head, tail, and feet

• 2.4% diaphragm and internal (visceral) fat

edible organs in the beef carcass

1. Tongue

2. Tail

3. Liver

4. Sweetbreads (thymus gland)

5. Hanging tender (thick diaphragm muscle)

6. Kidneys

7. Heart

beef carcass

1. Hide

2. Head and tail

3. Shanks of fore and himb legs

   1. Shanks: metacarpals in the forelimb and metatarsals in the hindlimb

4. Spinal cord

5. Internal organs and their contents

6. Internal fats

7. External cod fat (in pubic region)

8. Udder fat (if present)

hook

Beef carcass suspended by this through the achilles tendon.