MEAT SAFETY
Stunning to bleeding intervals
- According to legislation, animal must be bled within 60 seconds after stunning - Within 10 seconds (electrical stunning)
WET CARCASS SYNDROME IN SHEEP
- Due to dehydration and subsequent overhydration - Carcass retains glistening appearance due to buildup of fluid in subcut tissues -Don't dry out during chilling = Poor keeping quality
Problems that may occur with stunning and bleeding:
- Ecchymosis, blood splashing, blood spotting - Aspiration of ingesta - Aspiration of blood - Oversticking/backsticking
Abattoir slaughters 1500 pigs per day at a speed of 180 pigs per hour. How many personnel is needed for meat inspection?
- 5 meat examiners: 2 for hindquarters, 1 for forequarters, 1 for head - 2 meat inspectors: 1 for red offal and 1 for rough offal - 1 veterinarian (1 vet per 7 abattoirs)
Bleeding times
- 8 minutes for cattle, horses - 6 minutes for calves, pigs, sheep
Exsanguination times for species
- 14 seconds in sheep - 18 seconds in pigs - 85-120 seconds in calves - In adult cattle and horses much longer than calves
HANDLING OF DEAD ANIMALS
- All "dead on arrival" and "dead in pen" animals must be disposed of as CONDEMNED MATERIAL. - Before slaughtering them, a blood smear for anthrax must be done - No dead/dying animal may be brought into abattoir premises - PM = Owner's choice/if suspected controlled disease - Salvage of skin/hide sometimes done
MEAT INSPECTORS
- All the functions of meat examiner PLUS - Inspect animals before slaughter (ante-mortem inspection) - Conduct routine inspections AND enter and search premises - Write instructions regarding operation of abattoir ANTE-MORTEM INSPECTION PRIMARY MEAT INSPECTION
VETERINARIAN
- All the functions of meat examiners AND meat inspectors, PLUS - Amend, set aside or replace any decision made by the meat examiner/meat inspector - Condemn meat as unfit for human or animal consumption ANTE-MORTEM INSPECTION SECONDARY INSPECTION
A pre-slaughter rest period of 1 hour is needed to...
- Allow muscle glycogen replenishment - Results in better bleed out of carcass
Effect of catecholamines that are released in stressed animal
- Anabolic effect on muscle protein metabolism -> Bad for tenderness of meat - Increased blood supply to muscles -> Carcass not bleeding out well
Problems that may occur in relation to the restraining pen
- Animal handling in a stunning area becomes less efficient as number of animals become less on a fixed floor space size. - Hoist too slow - It is not always possible to stun an animal in the stunning area at the point of hoisting for bleeding - stunned animals are dragged across the floor to the point of hoisting. They may return to consciousness before they die from anoxia of the brain after throat cut/even before bleeding. - Sometimes, because of less efficient restraint in a stunning area, electrical stunning tongs are used for animal management purposes. This should not be allowed!
Sterilizers and hand wash-basins must be situated in places where...
- Animals are slaughtered - Carcasses, meat, offal are detained - Condemned material is handled - Meat is otherwise handled
Maximum time to keep animals in lairages
- Animals: No longer than 72h - Calves and pigs: No longer than 48h
Some pathogens that are inactivated by pH less than 6
- Brucella abortus - FMD virus - Mycobacteria (TB) - RVF virus NOT ASF (inactivated by heat of 84 deg)
On animal transport vehicle, there must be partitions to separate...
- Bulls and cows/heifers - Adult and young - Injured/blind and normal - Fractious and normal - Different species
These groups of animals may not be penned together
- Bulls and cows/heifers and cows - Cattle with long and short horns - Young and adults - Fractious and normal animals - Animals of different species
Stunning methods for each species
- Captive bolt method for cattle or horses - Electrical stunning method for sheep, goats, calves, small to medium pigs - Cardiac arrest stunning for sheep, pigs, cattle - Carbon dioxide gas method of stunning for pigs
These carcasses must be split lengthways:
- Cattle/horses older than 3 months - Pigs heavier than 92kg
CLEAN AREAS/ACTIVITIES
- Cloakrooms, toilets, showers, wash facilities and dining room of clean area workers - Slaughter hall for dressing of animals - Chilling of carcasses - Freezer facilities for freezing carcasses with light measles infestation - Sorting and loading of carcasses - Carcass dispatch facilities - Washing bay for meat trucks - Office for management - Laundry facilities - Meat inspection, carcass classification and weighing of carcasses
DIRTY AREAS/ACTIVITIES
- Cloakrooms, toilets, showers, washing facilities, dining room of dirty area workers - Livestock entrance - Vehicle wash bay for trucks that transported animals - Offloading platforms and facilities for marking animals - Lairage where animals are kept until they are slaughtered where applicable - Ante mortem inspection - Isolation lairage for animals/birds that are sick - Emergency slaughter facilities for hurt animals - Facilities where animals are restricted and stunned - Bleeding area - Facilities where condemned products/inedible products (hides/skins, horns, claws, hooves) - Rooms where rough offal is cleaned, packed and cartoned - Chiller or freezer facilities for rough offal - Dispatch area for rough offal - Facilities for the processing of condemned products to by-products like blood/carcass meal, tallow
Some abattoirs have problems with return to sensibility when animals are electrically stunned. Mention possible causes that you would investigate (trouble shooting) if you notice return to sensibility before bleeding is complete?
- Contact time of electrodes too short - Insufficient amperage - Poor bleeding technique - Poor initial contact of stunning tongs/dirty electrodes - Interrupted current (tongs sliding) - Wrong placement on head (missed shock) - Stunning to Bleed interval too long (for head-only electrical stunning, must be less than 10 seconds) - Hoist too slow - Stunning tongs poorly maintained
NB things to consider in transport of animals (that contribute to stress & injury)
- Don't overload vehicles - Don't load too few animals - Don't load sick, weak, tired animals - Separate horned from hornless animals - Don't mix strange and familiar animals - Don't leave loose articles on vehicle - Don't use sand on floor of vehicle.
Phase test
- Done on yellow carcasses - If upper ether part is yellow = Carotene pigment - If lower sodium hydroxide part is yellow = Bilirubin (icterus)
PALE SOFT EXUDATIVE MEAT
- Due to acute stress before slaughter (electric prodders, fighting, beating animals, overcrowding in lairages) - pH of meat drops to below 6 within 45 minutes after slaughter - Glycogen breaks down to lactic acid > Acidification of muscle happens faster > pH drops while carcass is still warm > Low pH + high BT = Denaturation of muscle proteins, causing a reduction in their water holding capacity > Fluid exudate in meat
DARK, FIRM AND DRY MEAT (dark cutting meat) IN CATTLE
- Due to chronic stress before slaughtering (long transport, long food deprivation) or growth promoters - Ultimate pH measured after 12-48 h is >6.3 - Chronic stress > Depletion of stored glycogen > Less glycogen available PM > Affects normal process of acidification > Leaves pH of meat high > Very little denaturation of proteins > Water is tightly bound
Alcohol floatation test
- For poor carcasses (emaciation/cachexia) - Pea sized bone marrow pieces collected by sawing through distal humerus + placed in each of 32%, 47% and 52% alcohol solutions. - Approve carcass if all the pieces of bone marrow float - for all three alcohol concentrations
ANTECHAMBER of personnel must include...
- Hand-wash basin - Soap dispenser - Hand drying facility - Boot wash - Apron wash and hook - Refuse container
Concepts to encourage workers to minimize systematic or incidental contamination (NB)
- Keep dry landing area clean and dry - Where possible use one knife to open skin and another to bleed - Sterilise bleeding knives between each animal - Do not incise udder tissue and spill milk over carcass - Make initial ventral skin cut outwards - Do not cut through skin and tissue simultaneously - Complete flaying and then eviscerate - Flap hides and skins away from meat - Encourage a clean hand : dirty hand concept - No elbowing with long sleeves - Encourage weasand rodding and tie off oesophagus in more sophisticated low throughput, all high throughput and export approved abattoirs - Do not insert spreader bars through skin/hide - Encourage evisceration within 30 minutes - Insist on skinning of anus bung and vulva - Avoid paunch rupture during brisket splitting - Avoid rupture of organs in situ, especially urinary bladder, uterus (particularly gravid), gall bladder, stomach or rumen, intestines - No hollow organ (including uterus, urinary bladder and gall bladder) may be opened in evisceration room/area. - Train slaughter men not to cut or forcefully remove adhesions: Abnormalities must be left for meat inspector to inspect - Slaughter men must not squeeze or damage organs - Avoid contact with floor - Do not allow walking/stepping on viscera - When abscesses are cut take immediate steps to prevent general soiling - Test water quality and standard regularly - Ensure removal of detergent residues from equipment - Keep all equipment clean and in a state of good repair - Avoid over-lubrication of overhead equipment - Keep sound and unsound material clearly separated
Reasons why animals should not stand too long in lairages
- Lairage contamination by faecal bacteria (salmonella) - Small calves refuse to eat in lairage - Animals (pigs) fight with each other
Why do we hang animals for bleeding?
- Leaves relatively low amount of blood in muscle. If bled in a lying position, have a high amount of blood in muscle → Meat does not reach necessary degree of acidity (pH 5.6 - 6.3) and its shelf-life is reduced. - A big principle of slaughter hygiene is to avoid contact between a carcass and floor. The carcass needs to be off ground as soon as possible during first steps of slaughtering process.
Advantages of cardiac arrest stunning
- Less risk of animal regaining consciousness. - From welfare perspective, it is not NB to bleed animal immediately. - It is no longer essential to cut either carotid arteries, or the brachiocephalic trunk in case of cattle and pigs, to ensure a humane slaughter. - Physical convulsions (clonic seizures) are reduced. - Less risk of blood splash and bruising in carcass.
Explain why inspecting the movement of stock during offloading and moving to pens is the best way to do it?
- Many abnormalities can be detected at an early stage - Affected animals are removed immediately to isolation pens for emergency slaughter/further examination. - It prevents both unnecessary suffering and spread of disease
Consequences of slaughtering animals with severely depleted muscle glycogen reserves
- Meat is more prone to spoilage - Pathogens like FMD, RVF will not be inactivated - Cattle: DFD beef - Pigs: PSE pork - Sheep: Ovine wet carcass syndrome
If the pH does not drop to below 6.3, what are the repercussions?
- Meat is more prone to spoilage (spoilage organisms grow more readily at high pH) - Meat is not as tender (proteolytic enzymes are not released)
Examples of carcasses judged to be inedible due to aesthetic reasons
- Melanosis - Telangiectasis - Unilocular renal cyst
CARBON DIOXIDE GAS METHOD
- Must reach highest concentration (> 84/90) in minimum of 30 seconds - Must remain in gas mixture for at least 160 seconds - Cause of death is "anaesthetic overdose" (causes a fall in pH of CSF)
Duration allowable for transport
- No longer than 36 h for all animals (except pigs) - In journey exceeding 36 h in pigs, they must stop at least every 24 h for a solid, 12 h resting period
What are signs of insensibility in pigs that were stunned using CO2?
- Pigs completely soft and limp - head hangs straight down and back is straight - Pigs must NOT have an arched back righting reflex. - No spontaneous natural blinking. - No response to a nose pinch or pinprick on the nose. - Animals entering a scalding tank must not make a movement that is in direct response to contact with the hot water.
The use of prodders in abattoirs must be discouraged. Mention at least five alternative types of driving aids (devices used to aid with moving animals through races and crushes) that can be safely used abattoirs
- Plastic paddle stick - Small flags - Old feed bags cut open at bottom - Old plastic aprons cut into ribbons, tied to stick - Piece of plasticized tarpaulin stiffened on each end
Stress factors during pre-slaughter period
- Pre-slaughter handling - Increased human contact - Transport - Unfamiliar environments - Hunger and thirst - Changes in social structure
MEAT EXAMINERS
- Receive in service training to inspect meat - May approve meat if it is fit for consumption - Ensure approved meat is marked, as prescribed - Detain abnormal meat for further inspection by a veterinarian - Must work under supervision of a veterinarian PRIMARY MEAT INSPECTION
Factors that will cause animals to block through races, passages, crushes in lairages.
- Reflection of floor - Air blowing in their faces - Animals move towards light (though not glaring) - Contrasting surfaces (e.g. concrete to metal floor) - Shining things - People seen outside crushes standing in wrong place - Drains inside pens
Lairage, pens and passages, crushes specifications
- Sides of pens: 1.8 m high for cattle, horses; 1 m high for pigs, sheep, goats - Pen gates: 1800 mm wide for cattle, horses; 800 mm wide for sheep, goats, calves and pigs - Water trough: 900 mm high for cattle, horses; 300 mm high for sheep, goats; water nipples (1:12) for pigs - Hay racks: Free from the floor - Lairage passages: 1.8 m wide for cattle, horses; 1 m wide for sheep, goats, pigs - Crushes leading to stunning area: Inner width of 0.9 m at most.
Well designed V restrainer has the following:
- Slats all same colour and free of broken, sharp edges - Feet must not lift off ground before animal is moved under the hold down - Must have a false floor (animal must not see drop under restrainer)
Key words as regards to ABATTOIR STANDARDS AND FINISHERS
- Smooth - Rounded - Impervious - Light coloured - Washable - Free of cracks and open joints - Resistance to wear and corrosion - Not slippery
Restraining facilities for each species
- Stunning box for cattle, horses - Restraining pen/crowding pen with hinged gate for sheep, goats, pigs - Restraining pen/stunning box for large, difficult boars/sows
Examples of conditions causing total condemnation of carcass
- TB - Pyaemia - Botulism - Black Quarter
When TB or CA animals are slaughtered, state vet/AHT must be present and...
- Take fresh specimens of lesions, specimens in formalin to confirm Dx - Correlate culture/histopath results with intradermal skin test result (TB)/serological results (CA) to determine at which point herd can be declared free of disease.
Aim of finishes in abattoir buildings
- To prevent buildup of bacteria - To make cleaning and disinfectant procedures easier - To promote hygiene
Depletion of muscle glycogen reserves during pre-slaughter period affects meat quality such as...
- Ultimate pH - Tenderness and ageing potential - Colour - Water-holding capacity
Outcome for carcass after secondary meat inspection
- Unconditionally passed as fit for human consumption - Totally condemned - Partially passed (by removing condemned part) or partial condemnation of a carcass/organ · Conditionally passed, subject to treatment (that meat is frozen for a certain time/ cooked/quarantined for some time)
Feeding young in lairages
- Unweaned piglets/calves (younger than 3 m/o) and unweaned lambs (younger than 2 m/o) must be fed. - Grain for piglets - Milk/substitute for calves, lambs, kids
Other means of restraining
- V restraining conveyor - Centre track conveyor restrainer
A unit consists of...
1 cow/ox/bull or 2 calves 1 horse 6 sheep/goats 4 small pigs (porkers)/2 bacon pigs/1 sausage pig
When captive bolt stunned animals are viewed from a distance, most NB signs to look for in a properly stunned animal are:
1. A floppy head 2. Tongue hangs straight out and is limp 3. The back and head hang straight down. There is no arched back righting reflex.
Provide requirements for premises of an abattoir
1. All areas of premises must be dust/mud free. 2. Provision must be made for storm water drainage (foundations also built up) 3. Equipped with enclosed drainage system for disposal of effluent + sewerage. 4. Vehicle loading/offloading areas for dispatching + receiving meat must be curbed, paved, drained and roofed.
Hygiene Management Program control points
1. Ante-mortem inspection 2. Slaughter and dressing 3. Meat inspection 4. Personal hygiene of workers 5. Medical fitness of workers 6. The temperature of water in sterilizers and maintenance of sterilizers 7. The availability of liquid soap and soap dispensers, toilet paper, and disposable towels, 8. Sanitation and continuous cleaning 9. Availability and quality of water 10. Vermin control 11. Waste disposal, including condemned material 12. In contact wrapping and packing materials 13. Maintenance 14. Thermo control
Maximum throughput in a high throughput abattoir is determined by PEO on grounds of...
1. Capacity of lairages 2. Hourly throughput potential relative to available equipment and facilities (hanging space, chiller capacity, rough offal handling capacity to stun and bleed animals humanely)
Regulations regarding cross flow in abattoir
1. Clean and dirty areas must be separated. 2. Ensures that no cross flow between clean and dirty areas occurs. 3. Ensures that detained meat can be kept and examined without contaminating passed meat. 4. Ensures that inedible/condemned material can easily be removed on a continual basis from areas where edible material is handled.
A certificate of registration for an abattoir is issued after...
1. Design drawings were approved 2. Slaughter facility was built according to specifications 3. Slaughter facility was suitably equipped by specialized engineering company 4. Slaughter facility was tested to determine if any further changes need to be made in placement of equipment, or if additional equipment is needed 5. A final inspection of slaughter facility and slaughter process was conducted by an authorized person 6. The outcome of the inspection was that the facility and slaughter process comply with every aspect of the law and regulations
AIMS OF ANTE-MORTEM INSPECTION
1. ID controlled/notifiable diseases 2. ID zoonoses 3. ID diseases that show symptoms in living but no signs at PM 4. ID animals with symptoms showing a particular organ system is affected to alert inspector doing PM inspection. 5. ID diseases which can infect other animals/humans 6. ID septic/purulent conditions that will infect slaughter floor + equipment 7. Prevent cruelty by removing injured/dying animals for emergency slaughter 8. To withhold animals excessively soiled with mud/oil/diesel 9. To separate C and T marked animals to be slaughtered at end of day 10. Obtain suspicion of AB substances, e.g. dye on hair, lumps on all animals
Signs of properly stunned animal (CAPTIVE BOLT)
1. Rhythmic breathing is absent 2. Animal doesn't blink/have eye reflex in response to touch 3. Eyes are wide open with blank stare 4. If eyes are rolled back/nystagmus, insensibility is questionable 5. Head + neck must be loose and floppy like rag 6. Tongue should hang out and be straight and limp 7. Its head hangs straight down + back is straight (no righting reflex) 8. Tail relaxes and hangs down 9. No response to nose pinch 10. No vocalisation
Describe the signs of a properly stunned animal (ELECTRICAL STUNNING):
1. Rhythmic breathing is absent 2. No blink response when light is shined into eye 3. Nystagmus is permissible 4. Head hangs straight down + back is straight (no arched back righting reflex) 5. Animal will clamp eyes shut, but then have a blank stare 6. No response to nose pinch 7. Pigs entering scalding tank make no responsive movement 8. No vocalisation
GRADES OF ABATTOIRS based on maximum daily output
1. Rural - 2 units 2. Low throughput - 20 units 3. High throughput - Max determined by PEO
Describe the order of the events which indicate return to sensibility after faulty electrical stunning
1. Single, feeble eye reflex in response to touch 2. Return of rhythmic breathing 3. Spontaneous natural blinking 4. Response to painful stimulus (pinching nose) 5. Righting reflex, raising its head 6. Fully conscious and sensible.
Causes of high pH in muscle
1. Stress factors 2. Too long distance/duration of journey 3. Injuries during transport 4. Transport of unfit/pregnant animals
Physical signs of effective mechanical stunning
1. TONIC PHASE · The front legs are extended, and hind legs are retracted into body for 5-15 seconds. The animal will have a fixed, glassed expression and no rhythmic breathing 2. CLONIC PHASE · Usually mild paddling, sometimes severe kicking
Any condemned material must be disposed of by one of the following methods:
1. Total incineration 2. Denaturing and burial of condemned material 3. Processing at a registered sterilizing plant 4. Alkaline hydrolysis 5. Combined with biogas plant
DECISION POSSIBILITIES FOLLOWING ANTE MORTEM INSPECTION
1. Unrestricted, normal slaughter 2. Approved for conditional slaughter 3. Isolated and detained for observation and possible treatment 4. Animals condemned outright, with or without hide/skin destroyed
Feed animals in lairages after...
24h (monogastrics) 48h (ruminants)
Warm running water for washing of hands must have a temperature of not less than...
40 degrees Celsius
Normal ultimate pH in meat is between...
5.6 - 6.3
Sterilizers must sterilize hand utensils and equipment at a minimum water temperature of...
82 degrees Celsius
FORBIDDEN SUBSTANCE
A harmful substance according to the Foodstuffs, Cosmetics and Disinfectants Act.
In terms of electrical stunning, amperage, frequency and voltage:
AMPERAGE - Sufficient amps to induce grand mal seizure and makes animal instantly insensible - Market-weight pigs: 1.3 amps - Sheep: 1 amp - Large sows: 2/more amps VOLTAGE - Sufficient voltage to deliver minimum amps FREQUENCY - Too high will result in failure to induce insensibility - 50 Hz recommended
LYMPH NODES INSPECTED IN HINDQUARTER
All are incised - Lnn iliaci medialis et lateralis - Lnn subiliacus - Lnn inguinalis superficialis - Lnn renalis
LYMPH NODES INSPECTED IN HEAD
All are incised - Lnn mandibulares - Lnn parotidei - Lnn retropharyngiales
LYMPH NODES IN RED OFFAL
All are incised - Lnn mediastinales - Lnn bronchiales - Ln hepaticus
CONDEMNED MATERIAL
Animal/parts of animal that is inspected and judged to be unacceptable for human and animal consumption, and requiring sterilization/destruction.
Slaughter ages for different species
Beef: 15-18 months Mutton: 8-10 months Porkers: 3-6 months Baconers: 7-10 months Sausage pigs: > 10 months Poultry: 28-42 days
Differentiating heat stress (AM) from blood splashing (PM) in pigs
By incising bronchial lymph nodes and trachea. Copious amounts of red tinged foam in trachea and bronchi (severe lung oedema) and blood in lymph nodes is indicative of ante-mortem heat stress.
Difference between condemned and inedible material
CONDEMNED MATERIAL · An animal or parts of an animal · Inspected and judged, or otherwise determined, to be unacceptable for human and animal consumption Requires sterilising or destruction INEDIBLE MATERIAL Parts of an animal unsuitable for human consumption but not requiring destruction Anything for which there isn't a viable market (pet food or otherwise) e.g. Claws, feathers, pig hair, LI of pigs, pig spleens, pig lungs
ANIMAL PRODUCTS PROCESSED IN CLEAN AREAS
Carcass Lungs Heart Thymus ("Sweetbreads") Diaphragm - if removed Tongues Kidney - if removed Liver Spleen Clean fat (omentum) Pancreas Tail Heifer udders - if removed Testes
A high pH (> 6.3) in a detained carcass will lead to...
Carcass being condemned (high suspicion that animal was ill and had fever before slaughter)
Final cause of death in animals in abattoir is
Cerebral anoxia
PROCESSING
Changing meat, other than cutting and portioning, dicing and mincing, to enhance it.
Temperatures
Chilling of carcass: Less than 7 overnight Chilling of red offal: Less than 7 within 16 hours Chilling of washed rough offal: -2 Chiller/freezer of condemned material: - 2 Chilling chicken carcasses: Below 10 Freezing of carcass/offal: -12 Dispatch area temperature: 12
Marking of condemned material
Cleary marked "CONDEMNED" using green ink
CUTTING
Deboning and portioning of carcasses
RED OFFAL
Demasked head, tongue, lungs, heart, diaphragm, liver, spleen
STUNNING IN POULTRY
ELECTRICAL WATER BATH - 4-7 seconds contact time - Saline solution increases conductivity Bird first shows a contractive spasm with an (1) Arching back of neck (2) Wings are characteristically folded over back (3) Eyes wide open (4) Both legs stretched rigidly Totally relaxed after 10-11 seconds
Why must animal be bled within 10 seconds after electrical stunning?
Electrical stunning causes a loss of consciousness for 35-45 seconds. Insensitivity/brain anoxia during exsanguination process takes ± 14 seconds in sheep and ± 18 seconds in pigs.
How does cardiac arrest stunning work?
Electrodes span the brain and heart causing tonic seizures and cardiac ventricular fibrillation
Why is it preferable to bleed pigs within 10 seconds after stunning? How can this be achieved?
Epilepsy protects welfare of animal by ensuring insensibility. Recovery occurs in a minimum time of 35 seconds → Need brain death before 35s With an accurate thoracic stick, loss of brain responsiveness requires 20s = 3s stun time, 10s from stunning to bleeding and 20s for the brain to die from anoxia ACHIEVED BY... · Reduce stunning time to 3 seconds · Reduce stun to bleed interval to 10 seconds. · Convert to a horizontal bleeding system to hasten stun to bleed interval.
All chemicals used in sanitation of abattoir must comply with this Act
Foodstuffs, Cosmetics and Disinfectants Ad
When does sanitation of abattoir commence?
Immediately after production for day or shift has ended BUT not before all edible meat and animal products have been removed to prevent contamination.
Possible disadvantage of cardiac arrest stunning
Might slow bleed-out slightly and necessitate expensive alterations to lengthen bleeding rail. Might be overcome by utilizing electrical bleeding rate accelerators (not in pigs though - PSE)
Rollermarking of measly carcass
Marked with red "MMM" that is 2 cm in height
AIM OF SECONDARY MEAT INSPECTION
Meat inspector must detain carcasses for this inspection if they suspects that the animal was... - Ill with controlled/notifiable disease (must be reported to PEO, SV for disease control) - Ill with diseases of socio-economic importance (must be reported to owner of animals) - Injured during pre-slaughter and slaughter period (so that corrective action can be taken) - Treated with/exposed to chemical that may be hazardous to health of consumer.
APPROVED MEAT
Meat passed by a registered inspector.
Describe what well designed offloading ramp, crowding pens and passages should look like.
OFFLOADING RAMP - Ramp must be designed in such a way that when vehicle is reversed against ramp, it fully covers the gap to the ramp. - There must be no danger of animals falling over sides of the ramp. - Off-loading ramps should be wide and straight. - Floor of the off-loading ramp must be roughened to prevent slipping. - Height of the ramp must not be less than that of vehicle. - The bed of vehicle must not be higher than off-loading ramp. Therefore, offloading ramps of variable heights to accommodate all types of vehicle is recommended. Mobile offloading ramp requirements: - Floor must have cleats at suitable spacing to prevent slipping - There must be non-see-through side panels to prevent animals from falling off/balking away - They must be long enough so angle of descent doesn't cause slipping - They must be broad enough for easy passage CROWDING PENS - Crowding pen gates must be solid to prevent animals from turning back - Floor of crowding pen must be flat (to minimize balking, pile-ups, injuries) - Passages (races) must be single file and must have see-through gates so animals maintain visual contact with their herd mates (except for pigs) - Provide steps where needed (animals move better uphill) - Curved races and round crowding pens make use of natural behavioural traits - Use shields (movement + people cause distractions and balking) - All surfaces must be cleaned regularly and no loose articles (tins, wires) must be left lying around - Avoid/eliminate sharp objects, protruding objects and narrow gates
LYMPH NODES IN ROUGH OFFAL
Observe/if needed, incise - Lnn gastrici - Lnn mesenterici cranialis et caudalis
LYMPH NODES INSPECTED IN FOREQUARTER
Only palpate - Lnn cervicalis superficialis
Examination of emergency slaughtered animal
PAY ATTENTION TO Blood content of - Intercostal veins - Small vessels beneath serosa of abdominal wall - In retroperitoneal fat in walls of pelvis All visible lymph nodes after carcass has been split Shoulder (examine and loosen) and acetabulum (open from medial aspect): Observe exposed connective tissue, fat, lymph nodes and articular surface Condition of musculature and abnormal odours and colour of carcass
Pigs are prone to heat stress. What will you find on PM and what are DD's for it? What can be done to prevent heat stress?
PM: Lung oedema, blood in pulmonary lymph nodes DD's (lung oedema + bleeding): Septicaemia, migration of nematodes through lungs, blood splashing due to defective electrical stunning equipment, delay between stunning and bleeding Prevent: Offload pigs ASAP, spray them with cold water upon arrival, keep them cool in lairages
INEDIBLE MATERIAL
Parts of animal unsuitable for human consumption, but not requiring destruction: - Claws - Feathers - LI/hair/spleen/lung of pigs
DRESSING
Progressive separation of an animal into a carcass, other edible parts and inedible material.
PROTECTIVE CLOTHING
Protective clothing must be light coloured, clean, in good repair and must include: 1. Safety hats 2. Hair nets 3. Beard nets 4. Head and shoulder capes 5. White gumboots and safety boots (washed) 6. Waterproof aprons
EVISCERATION
Removing contents of thoracic and abdominal cavities.
Prevention of blood splashing
STUNNING CATTLE · Animals should not be excited/stressed before stunning. · Stunning must be done quickly and effectively · Use appropriate cartridge or correct air pressure is essential, as is regular maintenance of stunning equipment. Avoid need for double stunning. · Bleeding should be carried out ASAP after stunning. ELECTRICAL STUNNING OF PIGS, SHEEP, GOATS · Minimise stress/excitement. · Animals should not remain in a restraining race for long periods + should be stunned at an even rate. · Use low stunning currents and short stunning times. · Lowest voltage found to give satisfactory stunning should be used. · Voltage and time settings are also affected length of fleece, amount of moisture on skin/hide in contact with electrodes, and type of machine in use. · Correct electrode placement and establishing right current flow (amperage) · Regular maintenance of equipment. (Electrodes should be kept clean, and, with probe types, points sharpened regularly.) · The animals should be bled ASAP after stunning.
ROUGH OFFAL
Skin-on head, stomach, intestines and feet
ANIMAL PRODUCTS PROCESSED IN DIRTY AREAS
Stomach/rumen and oesophagus Abomasum Intestines Skin on head, skin on feet (ruminants) Hides, skins Horns, hair, hooves Blood Bladder Male/female reproductive organs (lactating udders/penis) Gall bladder Condemned material
Treatment of conditionally passed measly carcass
TREATED BY FREEZING - As sides in a freezer that is -18C for 72 hours - As sides in a freezer that is -10C for 10 days · To reach a deep bone or core temperature of less than -6C, confirmed by registered inspector · After deboning... - The container/carton in which deboned meat is packed must be marked with letter "M" and date of introduction into freezer must be indicated o The core temperature of meat inside container must be below -6C before it can be released by registered inspector.
Aim of primary meat inspection
To remove all unhealthy, unwholesome, soiled or aesthetically unacceptable carcasses or viscera or portions of carcasses or viscera from the production line.
What is the aim of stunning?
To render an animal unconscious ASAP to prevent pain and suffering during the killing process.
Rollermarking
Used to do meat classification - grade and name of abattoir is on roller mark
Freezers and chillers must be free from... that can be absorbed by meat
Vermin Mould Bacterial growths Odour
Crowd pens and gates in pig lairages must have solid sides. The races, passages, or crushes leading to the stunning area must also have solid sides. Why is this necessary?
Want to block pigs seeing distractions outside the crowd pens, races, passages, or crushes, because pigs have wide angle vision and are naturally curious and easily alarmed. They are also aggressive towards unfamiliar pigs. Preferably pens in lairages should also have solid sides and solid gates to not arouse alarm behaviour.
Declaration of health and origin of all animals must be provided and must contain the following:
a. Date of delivery b. Name and address of owner/farm c. Number of animals and specie(s) d. Health status of herd(s) e. Medication, if given, as well as withdrawal periods and dates.
3 stages of sanitation
o Continuous cleaning o Postproduction sanitation program o Pre-production monitoring program
Additional precautions of workers slaughtering Brucellosis-positive cattle
o Increase spacing between carcasses on the line o Lower the line speed o Increase number of personnel on slaughter line o Insist that they wear aprons, rectal gloves covered with surgical gloves, masks fitted with a respirator and safety glasses/face shield.
Condensate forming or dripping on carcass is unacceptable as:
o Wet carcass surfaces are predisposed to growth of spoilage organisms and slime formation o Carcass contamination occurs o Carcass can become discoloured or marked o Carcass shelf life can be reduced
Measuring pH and temperature... Where?
pH: Into shoulder (M. triceps brachii)/semimembranosus muscle Temperature: M. gracilis
Categories of waste:
· Condemned material · Inedible material (hair, claws etc.) · Water used for cleaning · Manure · Blood · General waste e.g. paper, wrapping materials
Requirements for a basic training program in hygiene on induction:
· Correct procedures to follow in regard to handling of protective clothing · Hair and hand care, toilet awareness, general cleanliness · Correct use of equipment and tools + their cleaning and sterilisation. · Use of equipment in antechamber (e.g. new employee must scrub his gumboots and wash his/her hands meticulously with soap and water every time he/she enters abattoir). · How to prevent and report accidents. · How to make use of first aid room and report if they feel ill in any way or develop lesions on their hands o Prompt treatment of cuts or abrasions o Or referral to a health practitioner if a more severe illness (zoonotic or otherwise) is suspected. o NB!! One Health! · Take swabs of hands before and after washing and let them view micro-organisms in laboratory
Objectives of the isolation regulation
· Ensure only healthy, rested, uninjured, unsoiled, and appropriately identified animals are presented for slaughter · Always ensure responsible and humane handling of livestock in all situations · Maximize efficiency of animal movement by improving design of off-loading facilities, lairages, passages, crushes, races · Avoid financial loss associated with severe injuries, which could include condemnation due to bruising + even death · Minimize cross-contamination between animals with food-borne pathogens during pre-slaughter period · Maximize cleanliness of facilities so that hygiene of slaughter process is not compromised
Judgement of measly carcass
· HEAVY infestation: If one/more parasitic intermediate stages are found on the majority of incision surfaces, carcass must be condemned · LIGHT infestation: Where infestation is not excessive, carcass and organs may be passed on condition that it undergoes treatment. · NOTE: Pig carcasses are generally condemned irrespective of whether infestation was heavy or light. Dangerous zoonosis (neurocysticercosis)!
Names of some equipment that should be sterilized after use on each carcass
· Hand knife · Mechanical flaying knife · Foot cutter · Dressing trolleys · Spreader bars · Weasand rod · Brisket saw · Carcass cradles (sheep) · Carcass saw · Evisceration conveyors or trays
Some abattoirs use centre track conveyer systems or V-restrainer conveyer systems to restrain animals (cattle, sheep or pigs) prior to stunning. Sometimes these systems fail. Mention aspects that you would investigate if you noticed that animals refuse to enter the system or vocalized?
· Hold down of centre track or V-restrainer conveyer too low or too high · Hold down too short - feet must not lift off the ground until the animal moved under the hold down. If the animal can still see out when its front feet lift it will jump out. · Entrance too dark - will not enter if too dark · Floor too slick · No entrance ramp and animals must be forced onto the conveyer leading to frustration for the operators and severe animal abuse · No false floor - must not see a drop under the conveyer · No belly rails on the entrance of the centre track conveyer · Animal sees distractions · Broken sharp edges · Different coloured slats on the V-restrainer conveyer · One side of the V-restrainer conveyer runs faster · Animal not centred in the conveyer
Problems with electrical stunning: NB
· If interval between removal of a head-only electric stunner and bleeding is too long/if the throat is cut incorrectly, a pig may enter scalding tank, or a cow/sheep may have a limb or skin removed while still conscious. · Spasms and contractions interfere with shackling and bleeding. Employees will turn stunner voltage down to reduce kicking. This prevents tonic-clonic seizure and animal may therefore be sensible during shackling and bleeding. · Sometimes electrical stunning equipment is not routinely maintained. Electrodes often to develop a layer of charred material, which increases electrical resistance and reduces effectiveness of stunning. · An animal may escape from electrodes/initial contact is not enough to produce rigidity. Animal becomes distressed and a struggle follows which, in turn, makes it more difficult to apply electrodes. · Restraint in a conveyor or head bail (head clamp) assists accurate stunning but it may lead to additional stress in maneuvering animal into restrained position and in holding it there. Misapplication of tongs and the animal may experience an electric shock. · Blood splashing
Why do we perform "rodding the weasand?"
· It prevents rumen content soiling of neck, front legs and viscera in thoracic cavity due to retro flow of rumen contents · It prevents soiling of equipment + abattoir floor. · Without rodding the weasand, rate at which each passing carcass becomes soiled escalates and shelf life of meat obtained is markedly reduced.
A well-designed stunning box must incorporate the following features:
· Must be narrow enough to prevent the animal from turning around · Must have a non-slip floor · Feet must not slip under the door · Cattle must not see feet under the door
Predilection Sites for blood splashing
· Petechial lung haemorrhages (dorsal) in sheep and pig. · Muscular portion of diaphragm · Intercostal muscles · Transverse abdominal muscles · Sheep: Large intestine caecum and colon · Pigs: Hip, thigh & shoulder · Calves: Endocardium · Cattle: Neck, subcapsular spleen and Longissimus dorsi muscle
Methods to prevent contamination of carcasses
· Plastic on hind limbs and proper spacing of carcasses. · Prevent finger marks + palm prints by pulling carcasses with a hook instead of pushing them along. · Also wash hands more often.
Water for sanitation purposes must be...
· Potable · Hot water at a minimum of 82°C in sterilizers for disinfecting hand equipment · Water at 40°C at hand wash basins for washing of hands Water at 40°C for general cleaning purposes
Animal welfare indicators (critical control points) during transportation
· Slips and falls · Balks and reversals · Death during transit · Downers · Animals giving birth in transit · Animals injured or diseased · Weight losses and poor body condition · Weakness and dehydration · Dirty animals · Animals showing pain/distress or inability to move/walk/bear weight on all four limbs
Physical signs of effective electrical stunning in sheep, goats or pigs
· The limbs initially extend, back and head arch (tonic phase) and eyes close. · Electrodes should be removed after 3-5 seconds (stunning is an all-or-nothing event!!) · After about 10 seconds, muscles gradually relax followed by paddling movements (clonic phase).
Primary meat inspection of the forequarter
• Parietal pleura - Observe • Lnn cervicalis superficialis - Palpate • M triceps brachii - 1 deep transverse incision through distal part of muscle • Sternum, ribs, vertebrae of split carcasses - Observe
Regarding health checks and medical records
• All medical records are confidential. • Only a medical practitioner may have access to these records. • Ask for a list of employees and a file with all the medical certificates for each employee • Check whether every employee on list has a valid certificate on file • No personal information on certificate
Cleaning vs disinfection
• Cleaning is the process of removing soil • Disinfection is the process of reducing the number of microorganisms that are on a properly cleaned surface to a safe level.
Condemning a carcass
• Condemnation amounts to seizing of producers' property and destroying it without compensation • Make an aetiological/anatomical/morphological/pathological diagnosis • Evaluation must be reasoned and reasonable whilst not condemning unnecessarily producers' property.
PROHIBITIONS ON WORKERS
• Jewelry, including traditional objects, may not be worn in an area where edible products are handled • Fingernails must be short, clean and free of nail varnish • Eating, drinking is not allowed in any area where meat is handled - includes chewing gum • Handling tobacco is not allowed in any area where meat is handled. • Drugs, liquor or any intoxicating substance may not be brought into any part of premises. • A drugged/intoxicated person may not be allowed to enter any part of a meat handling plant. - Personnel must refrain from any contaminatory actions - coughing, sneezing and spitting
Primary meat inspection of hindquarter
• Parietal peritoneum - Observe • Lnn iliaci medialis et lateralis - Incise • Lnn subiliacus - Incise • Lnn inguinalis superficialis - Incise • Muscular part of diaphragm - 2 incisions 25 mm apart • Remove kidneys from their capsules and observe • Lnn renalis - Incise
Primary meat inspection of the head
• Skin, external surface of de-masked heads, eyes, nostrils, lips, gums, hard and soft palate - Observe • The external masseter muscles (M. masseter) - 2 deep linear incisions • The internal masseter muscles (M. pterigoideus) - 1 deep linear incision • Lnn mandibulares - Incise • Lnn parotidei - Incise • Lnn retropharyngiales - Incise • Tongue - Observe and palpate • Tonsils must be removed and condemned
Observe inside and outside surfaces of carcasses visually for:
• State of nutrition • Colour • Odour • Symmetry • Bruising & Injuries • Contamination • Efficiency of bleeding • Pathogenic conditions • Parasitic infestation • Injection marks
Approval stamp
• The stamp must contain registration number in at least two official languages, one of which must 6 cm across; 8mm text size o 2 languages - one top; one at bottom o Number in middle = First province number (6), then abattoir number A purple-coloured ink is required where stamps are applied to carcasses or meat The mark must be placed on each quarter of carcass (also on head of pigs or heads of other species if skinned)
Primary meat inspection of rough offal and feet
• Visceral peritoneum and omentum - observe • Gastric and mesenteric lymph nodes (Lnn. Gastrici and Lnn. Mesenterici cranialis et caudalis): Observe/if necessary, incise • Lactating udders o Removed and condemned before flaying o Keep Lnn. Inguinalis superficialis intact Feet - Observe
Primary meat inspection of red offal
• Visceral pleura - Observe • Oesophagus, thyroid gland, both sides of diaphragm, spleen, testes, tail - Observe • Lungs - Palpate and incise • Trachea - Incise • Lnn mediastinales and Lnn bronchiales - Incise • Liver - Palpate and incise • Ln hepaticus - Incise • Pericardium - Observe and cut open to expose epicardium • Heart - 3 incisions to expose endocardium and heart valves
Additional incisions made to look for intermediate stages of cysticercus in cattle and pigs
• When inspecting head - External masseters (M. masseter), by making two deep linear incisions parallel to mandible and internal masseters (M. pterigoideus medialis) by making a single deep linear incision - In case of cattle, tongue must be observed and palpated • When inspecting red offal - pericardium and heart, by an incision made lengthwise to cut through interventricular septum and open ventricles and two additional vertical cuts into split septum • When inspecting hindquarter - muscular part of diaphragm, by making two incisions approximately 25 mm apart and removing peritoneal layer to expose muscle • When inspecting forequarter - M. triceps brachii, by making one deep transverse incision through distal part of muscle. In case of pigs weighing between 54 kg and 92 kg these incisions may be omitted provided that heart is inspected and no cysticerci are found elsewhere in carcass