Mortaility rates during transport (lambs, pigs, broilers)
Lambs: 0.02%
Pigs: 0.07%
Broilers: 0.25%
Common causes of DOA in a) pigs b) sheep c) broilers
a) pigs: hyperthermia, metabolic acidosis
b) sheep: Smothering, ill health
c) broilers: Congestive heart failure, trauma
Presentation of DOA chicken with heart failure
Ascites (abdo full of fluid)
76% of fatal trauma in chickens is ….
Dislocated or broken hip 76&
Ruptured liver: 11%
% of birds with broken bones is higher in broilers or hens
More broken bones in hens due to calcium deficiency/ tend to be older/ free range barns systems more opportunity for trauma.
How should horned cows be transported
Can cut ends of horns off before transport.
Transport at lower stocking density but not too low as will fall over etc.
Why is Dark cutting beef formed?
DCB and Dark firm dry pork (DFD/ DCB) is a too SLOW rate of decline in pH.
What events leads to Pale Soft Exudative Pork
PSE = Stress immediately prior to slaughter. Poor water holding ability. Too quick rate of decline of pH due to depletion of glycogen too quickly
How to reduce antemorten stress for pigs
- Don’t transport unfamiliar groups of pigs together
- Decrease lighting
- Sprinkers to keep cool
- Give small amount of food to distract??
How to avoid high pH meat
Reduce pre slaughter activity and stress.
Alllow recovery of muscle glycogen (decrease lactic acid)
Enhance muscle glycogen stores.
Effects of dehydration of meat
Poor welfare, difficult skin removal (ripping of muscle0
Sticky meat,
Darker, tougher meat
Smaller loin muscle area.
Law regarding animal transport to abattoir
Must be weight bearing on all 4 limbs or individually transported (to prevent trampling)
Batch of poultry is slaughtered without the vet seeing them before. ???
Without ante-mortem inspection all poultry not inspected will be condemned .
animal slaughtered without passport =
Farmer has 48 hours to present passport.
Animal identifier is responsibility of FARM BUSINESS OPERATOR
When to reject carcass of mastitis cull cow
If systemic signs e.g. pyrexia = reject
Clenbutarol use pre slaughter
USA allowed Beta agonists
UK Beta agonists e.g. clenbutarol is banned as a growth promotor but used to relax uterus at parturition/breathing etc.
Why are knives rarely used in pig PM c.f. cows
Pigs = mainly visual inspection to reduce x contaimination,
Cows need to check for TB which requries incision into LN.
Difference between Oval health mark and Special health mark
Oval health mark: Country, approval no slaughterhouse - CAN BE EXPORTED.
Square mark: Emergency slaugher therefore can’t be exported
Traumatic reticulitis carcass=
Total carcass condemnation
Notifiable diseases at slaughterhouse
Anthrax, Brucellosis, EBL, TSEs (Scapie/BSE), TB,
Animal health act 1981
`Anthrax PM SIGNS
Lungs/LN are congested
Dressed carcasses appear ill bled and fevered
Spleen often enlarged (softer and darker)
Intenstines may in inflamed
DON’T OPEN CARCASS
Testing from Bovine Brucellosis
Paired LN (Retropharangeal)
Supramammary (female), Superficial Inguinal (Male)
TESTICLES IN BULLS
If no lesions found, check udder + genital tract + blood
Which tumours are notifiabe in cows
ALL TUMOURS NOTIFIABLE exc. papilloma or haemangiomata.
If <2 - Samping required. APHA investigation
How to tell if animal is a) 2?
Important for suspition of EBL i.e. if tumours present
3 yrs= 2nd pair of incisors erupted.
TB cases slaughter
Seperate slaughterhouse or slaughtered LAST.
CCleaning and Disinfection of premises mandatory after slaughter.
Only rejected in lesions in more than one place i.e. LN of lungs and head.
2 types of pasteurisation
Low temperature, long time
High temperature, short time - More common method.
Fat content of cream makes it necessary to apply higher temp
Most heat resistant non-sporulating pathogen likely to be present in milk
C. burnettii is the most heat-resistant non sporulating pathogen.
Pasteurisation is designed to achieve at least a 5 log reduction
Flow in heat exchanges
Flow should be turbulent i.e. high Reynolds number si ensure each particle is sufficiently heated.
All products subjected to pasteurisation should show a negative _______ reaction immediately after the treatment
Negative alkaline phosphatase reaction immediately after the heat treatment.
Alkaline phosphatase can be reactivated in many milk products therefore test must be performed immediately
Which salmonella infects poultry
Salmonella Enteritdis
Egg wash procedure
Eggs should not be soaked prior to or during washing
If eggs are washed they should be dried to prevent microbial growth
Milk consumption trend
Decrease.
Increase in yogurt has increased
Average number of cows per herd and average production per cow?
Average: 126 cows per herd
Average production: 7535l/cow/annum
Legislation of raw drinking milk
Allowed in England, Wales and NI but banned in Scotland since 2004.
Subject to restrictions: Must be from a TB free herd
Restrictions for raw drinking milk
Do not show any symptoms of infectious disease communicable to humans through milk
Good general health
No udder wound likely to affect milk
No unauthorised substrates/ follow withdrawel period
Belong to a herd that is TB free or officially free of brucellosis
Current controls on selling raw drinking milk
May only be sold direct to consumers by registered milk production holdings (farm gate)
Sales by farmers at farmers markets are allowed
Milk must bear appropriate health warnings
Monitorered by inspections twice a year
Milk sampled and tested quarterly under control of agency to monitor bacterial count/coliforms
Legal requirement for SCC
<400,000 SCC/ml
Milk processing has to occur within ___hrs of arriving at plant and involves…
Milk must be processed within 72 hours of receipt at plant.
1. filtration 2. clarification 3. decreaming (removal of fat through centrifugation) 4. Standardisation 5. Heat treatment 6. Homogenisation 7. Cooling 8. Filling/Storage
HTST procedure
High temperature, short time. Continuous.
72 degrees for 15 seconds BUT INCREASED in UK to 72 degrees for 25 seconds. to reduce risk of Mycobacterium avium subsp. paratuberculosis (MAP)
Properly pasteurised milk is Alkaline phosphatase negative
HTST vs LTLT
High temp, short time (CONTINUOUS- MORE COMMON) and Low temperature, long time (BATCH)
Temperature for UHT milk
135-150 degrees for 2 to 5 seconds,
Continuous operation.
Direct mixing of steam with product
Disadvantage of UHT milk
Changes to milk composition are minimal but there is a reduction in vitamin content
UHT results in change in flavour (deteriorates over time)
Sterility has to be maintained.
Long shelf life >6 months without refrid
Is milk sterile?
Milk is virtually sterile when synthesised in mammary gland of healthy cow.
Can be contaminated at any stage
Pseudomonas, Bacillus, Clostridium, Lactobacillus, Micrococcus, Streptococcus (CAN ALL SURVIVE PASTERUISATION)
During cheese making a starter culture and lactic acid are added. Function of these
Starter culture: Bacterial fermentation –> Lactic acid
Rennet = Coagulation of Casein
B
Butter raw materials
On average 82% fat
Raw materials: Fresh crea,
Adding salt to inhibit bacterial growth
Starter culture
Yoghurt addition of starter culture which includes
Strep. thermophiles and Lactobacillus delbrucekii
Other: Bifidobacterium
pH: 4.2 to 4.3