Lecture 23 Milk Hygiene and Poultry Inspection Flashcards
Who is responsible for the public health safety of food including milk and milk products?
U.S. Food and Drug Administration (FDA) i
The primary tool for regulation and monitoring of production and sell of Grade A milk is?
U.S. Public Health Service – Grade A Pasteurized Milk
Ordinance (PMO)
All raw milk is tested for
beta lactam antibiotics
Who helps ensure compliances with PMO?
- The National Conference on Interstate Milk Shipments (NCIMS),
helps set standards and ensures compliance
Who oversees Grade B milk manufacturing?
established and
overseen by USDA
What are the requirements of Grade A raw milk pasteurizations?
- *Milk from an individual producer can not have more
than100,000 bacteria per ml and < 750,000 somatic cells per ml. - After mixing with milk from other producers (comingling), not
more than 300,000 bacteria/ml - Must NOT have detectable antibiotic residues
- Cooled <45F within 2 hours of first milking
Grade A pastereurized milk and milk product bacterial limits must not exceed:
20,000 per ml;
Grade A pastereurized milk and milk product coliforms musts not exceed:
10 per ml
How is grade (formerly Grade B) raw milk manufactured?
Milk from an individual producer can not have more than1,000,000
bacteria per ml
* After commingling, not more than 3,000,000 bacteria/ml
* Must NOT have detectable antibiotic residues
* Can only be used for cheese, powdered milk, etc
Inspection Standards Summary:
Grade A:
- “Voluntary” program
- Adhere to Pasteurized Milk Ordinance (PMO)
- Prescriptive and higher standards
- Farm inspection 2x/yr
- Plant inspection 4x/yr
- Required for yoghurt and fluid milk
Inspection Standards Summary
Grade B:
- Everyone else
- USDA Guidelines for Milk for Manufacturing purposes
- More Lenient
- Farm inspection 1x/year
- Plant inspection 2x/yr
- Cheese, butter, ice cream…
Grade A pasteurized cultured products has no:
- limit on total bacterial count
- BUT coliforms cant exceed 10 per ml
How must you store milk products?
- Nonlactating separate from lactating drugs
Other chemicals/drugs not in the milkhouse
* Pesticides
* Small animal drugs
How do you prevent drug residues?
Avoid mixing up drugs
* Clear identification
What are the requirements for drug labelling?
Drug labelling requirements are consistent with AMDUCA
* Prescription
* Over-the-Counter
* Extra label
What are the common causes of milk residues?
- Not identifying treated cows and/or no treatment records
- Not segregating treated cows (fence jumping)
- Using common milking equipment or vacuums for treated and healthy
cows - Failure to observe the milk discard time indicated on the drug label.
What are the basic steps in milk processing at the plants?
- Filtration/Clarification
- Separation
- Standardization
- Pasteurization
a. Regeneration unit
b. Pasteurization unit
c. Holding tubes - Flow diversion valve
- Homogenization
- Deaeration (or
Vacuumization) - Refrigeration
What is filtration/clarification?
Raw milk is pumped under pressure through a filter to remove
visible dirt and foreign particles.
* The filter does not remove leukocytes or bacteria. A centrifugal
clarifier may also be used
What is separation?
Centrifugal force separates the lighter cream from the milk serum (skim milk)
What is standardization?
Skim milk and cream are re-mixed to achieve an exact butter
fat content of a product (e.g., 1% or 2% milk).
* Whole milk has a minimum of 3.25% butter fat content and
skim milk has < 0.5% butter fat.
What is pasteurization?
The pasteurization process is often divided into three parts
* Regeneration unit
* Pasteurization unit
* Holding tubes
High temperature, short time (HTST):
* 720C/1610F for 15 seconds; 16-21 day shelf life
Ultra high temperature (UHT):
* 1380C/2800F for 2 seconds; extended shelf life of 2-3 months
What is the flow diversion valve?
Measures the temperature of the milk
* If it is below one of the acceptable pasteurization temperature, Then milk is diverted to the raw milk tank
* And goes through the process again.
What is homogenization?
- The atomization of milk under high pressure to break the globules down to approximately 2 µg or less.
- Homogenized milk will not separate, tastes richer and is more
digestible. - This unit is often found between the regeneration and
pasteurization units.
What is deaeration (or vacuumization)?
- Expels gases and malodorous volatile substances.
- Used by some plants to remove “feed” flavor (often associated with
the feeding of certain silage) and undesirable odors (e.g. wild onion).
What is refrigeration?
- Once pasteurized, milk must be reduced to less than 40 F as soon as
possible to slow deterioration. - Shelf life is dependent on the temperature and time of pasteurization.
What are some important pathogens that pasteurization will kill?
- Mycobacterium spp. (TB)
- Coxiella burnetti
- Listeria monocytogenes
- Salmonella spp.
- Campylobacter jejuni
- Yersenia enterocolitica
- E.coli O157:H7
- Brucella spp.
You should refrigerate pasteurized milk at what temp?
40 F or below!
What are the two main milk standards?
Grade A
Manufacturing/Grade B
Why should you only Consume pasteurized milk and milk products?
- People get ill from consuming raw milk and milk products.
- Children, older adults, and immunocompromised people are at greater risk.
Who are key stakeholders in milk safety?
- FDA USDA and States key stakeholders
PMO and NCIMS-guidelines
Pasteurization guidelines:
- (HTST): 720C/1610F for 15 seconds; 16-21 day shelf life.
- Ultra high temperature (UHT): 1380C/2800F for 2 seconds; extended shelf life of 2-3 months
What is the Poultry Products Inspection Act of 1957?
required all slaughtered poultry moving in interstate or foreign
commerce to be inspected.
What is the Wholesome Poultry Products Act in 1968?
required all poultry both inter- and intra-state to be inspected.
Describe poultry AM.
- Inspection occurs in batteries, on a lot basis.
- Like livestock, inspection must occur on the day of slaughter.
- Inspection performed-Food Inspector or the Public Health Veterinarian (PHV).
- Focus on off-line inspection-condemnation can be
done without PHV presence or consult.
During the inspection, overall condition of the birds will be assessed with attention to the
following:
* Head, with attention to the eyes
* Legs
* Body
* Unusual swellings or other abnormalities
Deads condemned on antemortem
In poultry AM what does not apply? instead this is used?
Humane Methods of Slaughter Act does not apply. Good commercial practices (GCP) used
What non-diseased factors can influence the physical appearance of the animal which can confuse the disease status during the poultry AM inspection?
- Season of the year
- Heat
- Humidity
- Freezing rain
- Distance hauled to the plant
- Number of birds in a coop
- Time withdrawn from feed and water prior to
slaughter
During poultry processing after inspection:
the viscera are removed: the edible parts called
giblets (heart, liver, gizzard, and sometime the neck) are
removed and processed separately.
Poultry PM disposition
If a bird has tuberculosis with tuberculosis lesions these are called? and what happens to carcass?
Miliary nodules and are not calcified
Carcass is condemned
Poultry PM disposition
Leukosis lesion resembles lesions of what other disease? If bird has this what is required of it?
- The lesions may resemble those of tuberculosis with tumors in the bone marrow, liver and spleen.
- Regulations required the condemnation of a carcass having any
evidence of leukosis
Poultry PM disposition
What is Marek’s disease?
Marek’s Disease will cause inflammation and tumors in the nerves, spinal column, and brain. In this form, birds will become paralyzed in the legs, or wings or may develop head tremors.
Fatal and condemns them?
Poultry PM disposition
Septicemia-toxemia
carcass condemnation
Poultry PM disposition
Synovitis
Carcass condemnation due to systemic involvement and/or septic/toxic changes (often mycoplasma spps)
Poultry PM disposition
Tumor
whole carcass condemned
Poultry PM disposition
Bruises
Any badly bruised part shall be removed and condemned (e.g., a
broken leg). If the bruised part can be completely removed, rest of the carcass may continue if normal.
Poultry PM disposition
Cadaver
condemned
Poultry PM disposition
Contamination
Any contaminant on any part of a carcass causes that whole carcass to be condemned.
Plants are not allowed to wash off contamination.
Poultry PM disposition
Overscald
Overscalds are birds that have remained in the scalding vat too long.
Overscalds are condemned
Results in overcooking of meat
Poultry PM disposition
Airsacculitis
condemned
Infection of the airsacs, hyperperfusion and exudate, can be slightly thick and opaque
Describe the chicken ovary.
When a hen reaches sexual maturity, the yolks begin to mature one at a time. Each
mature yolk is composed of the germ spot (germinal disc), a fatty substance known as yolk, and the yolk membrane, called the vitelline membrane. The
vitelline membrane and its contents are covered by an ovarian membrane, which
is very vascular except for an avascular zone known as the stigma, through which
the yolk ruptures. The release of the yolk (ovulation) occurs again about 30 minutes
after a finished egg has been laid (oviposition). During the laying “clutch” of a high producing hen, oviposition can occur as often as every 22 hours but 24 to 26 hours is an average. Egg production is reported as a percentage, with 1 egg per hen per day representing 100% production.
What is the infundibulum?
funnel-shaped structure that receives the yolk after it is released from
the ovary and is the place where fertilization occurs in flocks where fertile eggs are
produced. It has sperm host glands that store sperm for eventual release for
fertilization. Approximate time spent in this section: 15 minutes
What is the magnum?
Yolk is released, peristalsis of the infundibulum conveys the yolk into the magnum of the oviduct. The front part or anterior portion of the magnum secretes a dense plastic-like gel made up of threadlike strands.
This gel forms the chalaziferous layer.
As the egg travels along the oviduct, it rotates, causing a ropelike twisting of the
threads that result in the chalaza in the completed egg. This structure serves to hold the yolk and germinal disc suspended in the middle of the egg shell and keeps the germinal disc up during incubation.
The dense, thick white is secreted in the last part of the magnum. The chalaza and
thick white (albumen) are interwoven to provide a firm support for the yolk.
Approximate time spent in this area : 3 hours
What is the isthmus?
the inner and outer shell membranes are developed around the dense white
Made of keratin and provide defense against bacterial invasion
What is the uterus?
The thin white is secreted
Calcium carbonate is deposited
The cuticle, a waxy, mucus-like substance is secreted <– final barrier that protects the egg
What is the vagina?
Holds the completely formed egg
Allowing the exterior shell to dry and become hard before the egg is released
Important to know:
Most companies wash the eggs before sending them to markets.
Washing eggs decreases outer shell contamination, removes the protective waxy
coating (cuticle), but does nothing about internal contamination (e.g., Salmonella enteritidis which colonizes between the shell membranes). Waxing is performed
following washing to seal off egg pores.
What are some abnormalities of commercial eggs?
- Foreign bodies
- Multiple yolks
- Blood spot
- Blood ring
- Mold
- Shell crack
- Abnormal shell
What is candling?
a process whereby the egg passes over a strong light source
that partially illuminates the inside of the egg
What are some foreign bodies?
- Pieces of straw
- kernels of corn
- Intestinal parasites (i.e., ascarids)
Egg is condemned
If an egg has multiple yolks is it condemned?
no
If an egg has bloodspots or blood rings is it condemned?
yes
If an egg has shell cracks or mold is it condemned?
yes
What is backyard poultry egg handling?
- PPIA provides guidelines
- Municipalities promulgate ordinances
- Often roosters not allowed
- Under 1000 birds and direct sales to consumer-exempt
- Dirty eggs can be buffed clean with an emory cloth
- Eggs should be gathered and refrigerated promptly
- Processing poultry exempt, if for personal use or direct sales to hotels, restaurant, etc
