lab 1- Antemortem and postmortem inspection of pigs and cattle.

Antemortem examination should be performed within

24hrs

If not slaughtered during this time will have to be re-examined.

Reasons for antemortem exam

– identifies animals:

- with clear evidence of disease, that could render meat unfit for human

consumption.

- that could pose a threat to handling personnel (ringworm)

- suspected of having disease.

- Suspected of being treated with antibiotics / chemicals.

- With reportable or exotic disease.

- That require special handling for humane reasons.

Categories of abnormalities during initial antemortem exam:

1. breathing

2. behavour

3. gait

4. posture

5. discharge/ protrusions from body openings

6. colour

7. appearence

8. odour

dark blue

– gangrenous udder.

Postmortem examination purpose

to protect the public health by ensuring that the carcases and parts that enter commerce are wholesome, not adulterated and properly marked, labelled and packaged.

=> Thus carcasses and parts that are unwholesome or adulterated are unfit for human consumption and dont enter commerce.

3 possible outcomes at postmortem inspection:

1. Passed - eligible for marks of inspection

2. Suspect - must be retained for detailed examination.

3. Condemned -not eligible to receive marks of inspection & cant enter commerce.

General methods for postmortem examination:

- Sight → observing disease lesion.

- Feel → palpating lumps / firmness in skin and organs.

- Smell → urine smell - uremia, contents of burst abcess.

- Hearing → listening to the carcase fall of line on to floor.

Importance of lymph nodes:

diseases , abnormalities and contamination can occur at any part of the body but they are most likely to occur as lesions in specific locations.

Primary importance = lymphatic system.

Differ in shape and size but should have firmness between warm fat and muscle.

Colour ranges from grey brown to fat coloured.

Lymph nodes and tissue responses during PHV’s examination of retained carcase will determine

the location and severity of the condition and whether or not the disease has begun to spread.

Some lymph nodes and tissues need to be incised.

First cut must be smooth, not ragged or lesions will be harder to detect.

- They should be cut in thin parallel slices.

Steps in post mortem examination:

1. Head inspection

2. Viscera inspection

3. Carcase inspection.

When abnormalities detected during inspection the following actions occur:

1. If the disease / condition is localised in head, organ or carcase → the plant trim the affected tissues.

2. If the disease is generalised and affected majority of the head, organ or carcase → it

is retained for veterinary disposition.

Swine viscera inspection:

Abdominal cavity contents.

viscera inspection steps

1. observe eviscerated carcass, viscera and pariteal surface of spleen

2. oberserve and palpate mesenteric LN

3. palp portal LN

4. oberserve dorsal (curved) surface of lung

5. palp bronchial LN

6. observe mediastinal LN

7. turn over lungs and observe ventral (flat) surfaces

8. observe heart

9. observe dorsal (curved) surface of liver

10. turn liver over and observe ventral (flat) surface

Swine carcase inspection:

1. Observe the back of the carcase.

2. Observe front parts and inside carcases

- Cut surfaces, cavities, lumber and neck region

3. Observe kidneys.

Head inspection:

1. Head tissue → observe outer surface of the head and eyes

2. Lymph nodes → incise and observe mandibular, parotid, lateral and medial

reteropharyngeal.

3. Cheek muscles → incise and observe.

4. Tongue. → observe and palpate.

Methods of carcase inspection:

1. “bed” dress

2. on the rail

“Bed” dress

Oldest method

- Still widely used, most often in low volume plants.

“On the rail”

Designed with volume in mind

- Animals are moved around the slaughter house on a rail.

- Instead of one employee dressing the entire animal, there are several

specialists that perform their jobs as the carcase moves past them.

- Following rail inspection the carcass will be moved to final wash area. Any

carcases located on the final rail must be physically separated from

other carcases to prevent cross contamination.

sanitary requ in both methods

All grubs, contamination and bruises on the back must be trimmed before the

carcase is split.

- Its not required to sanitise the saw between carcases however if a carcase has been

retained the saw must be sanitised.

- Employees must not removed any abnormalities that could affect the

disposition of the carcase.