Preventing Biological Hazards from Cull Dairy Cattle

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Preventing Biological Hazards from Cull Dairy
Cattle

• The California Dairy Quality Assurance Program
• CDFA USDAFSIS

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Biological Hazards Outline

• Bacterial Pathogens
• Cancers
• Common causes for condemnation at slaughter

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The Unseen Problems- Foodborne Bacteria

• Some bacteria that cause severe illness in people
  cause little or no obvious disease in cattle
• From cattle, these organisms can enter the
  food-chain without detection by traditional
  inspection techniques

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Bacteria of Concern

• Salmonella spp.
• E. coli O157H7
• Listeria monocytogenes
• Campylobacter jejuni

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SalmonellaA Common Food borne Bacteria

• 2300 serotypes many are shared between humans
  and animals
• Found in meat and poultry products
• Grow on many food products
• From cross-contamination
• Sprouts, melons, other fresh produce
• S. typhimurium DT104 account for many human
  infections

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Salmonella typhimurium DT104

• This serovar grows in many animals
• Resistant to multiple antibiotics difficult to
  treat human cases
• Gastrointestinal tract of many species - humans,
  birds, reptiles
• Milk, beef, pork, poultry meat, sausage

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Salmonella bacteria

• Effects on animals
• Cattle - diarrhea, decrease milk production,
  abortion. Death in cows and calves
• Recovered cows may become passive carriers.
• 75 of California dairies found to have
  salmonella
• Effects on humans
• More severe symptoms, more deaths, difficult to
  treat
• 696,000 to 3,840,00 case per year with 0.1
  mortality annually in US

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Salmonella

• Mode of Transmission
• Direct contact with live animals
• Contamination of foods beef, milk, others
• Preventive Steps
• Veterinary herd health program, judicious drug
  use
• Implementation of biosecurity measures
• Pasteurization, sanitation, refrigeration

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Escherichia coli O157H7

• O157H7 is one of many strains of E. coli. A few
  are pathogens, most are not.
• This is the hamburger E coli.
• This bacteria causes disease in people by
  producing toxins as it grows after being eaten.

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Escherichia coli O157H7

• Effects on animals
• Insignificant clinical problems in cattle.
• Effects on humans
• Clinical signs - diarrhea, cramping, vomiting,
  c) hemolytic urinary syndrome (HUS)
• The most severe cases appear in young children
  most often.

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Escherichia coli O157H7

• Mode of transmission to people
• Eating undercooked hamburger and other meats
• Eating contaminated veggies
• Drinking raw milk and juices
• Contaminated drinking water
• Swimming in contaminated ponds
• Daycare centers and nursing homes
• Farm visits

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E coli O157 can be found on most dairies,
but very few animals will be shedding at any one
time.
Often found in water troughs and wet feeds.
Most common in weaned calves least common
in adults.
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E coli O157
Highest level of E coli O157 is in cull
cows getting ready to go to slaughter.
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Risk factors for E coli O157 isolation.
More common on dairies with flush alleys and in
the warmer months.
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Risk factors for E coli O157 isolation.
Wet feeds such as silage particularly improperly
cured.
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E coli O157 Risk Reduction
Proper silage preparation insure proper low pH.
Frequent cleaning of water troughs and
chlorination of water.
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E coli O157 Risk Reduction
Compost manure used for bedding to reduce
bacterial levels
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Listeria monocytogenes

• Effects on animals
• Generalized illness with abnormal behavior and
  posture (Circling Disease)
• Effects on humans
• Influenza-like symptoms with nausea, vomiting and
  diarrhea.
• Systemic infection that may result in
  neurological signs and and abortions.

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Listeria in cattle
From poorly fermented silage
Nervous conditions in cattle circling and
abnormal posture
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Listeria Prevention
Dont send cows sick with nervous signs to
slaughter.
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Production and Storage of Feeds

• Proper prepared silage will reduce the risk of
  Listeria

Avoid feeding spoiled silages
Test pH
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Campylobacter jejuni (Vibrio)

• Organism Characteristics
• A common organism that has very specific
  requirements for growth
• Susceptible to freezing, and drying but is heat
  tolerant
• Where it is found
• Birds, mammals, and wildlife manure
• Undercook poultry and raw milk or untreated water
  are leading vehicles in U.S.

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Campylobacter jejuni

• Effects on animals
• Very rarely a problem in animals
• Poultry - skin/meat contamination
• Effects on humans
• Leading cause of sporadic food-borne illness
  sporadic summertime cases of diarrhea and cramps
• Outbreaks in spring and fall from raw milk or
  water
• Common in infants young adults sometimes
  followed by chronic problems

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Campylobacter jejuni

• Mode of transmission
• Fecal contamination of skin, meat and milk,
  direct from milk, contaminated surface water,
  human shedders
• Prevention
• Difficult on the farm unknown reservoirs
• Pasteurization, sanitation, refrigeration
• Hygiene in kitchen, cook food well, avoid
  cross-contamination

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Foodborne Bacteria On-FarmWhat Can We Do?

• We have a little knowledge yet of what can be
  done
• However, there are some practices that should
  help reduce the risks of food borne bacterial
  contamination of cull cows

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Potential Points of Entry, and Movement of
Bacteria in the Dairy Industry
Equipment/ Trucks
Calf Raiser
Other Dairies
Dairy
Meat
Packing- house
Transport.
Rodents Birds Reptiles Wildlife
Feed
Waste Water-Manure
Workers
Dairys Crop Prod
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Manure and Waste Water(Potential for
maintaining organisms on an effected farm)

• Survivors in Manure and Water include
• Many Salmonella species
• Listeria, E. coli O157

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On-farm control of bacteria for risk reduction
Proper composting greatly reduces the bacterial
load of manure.
Stacking and heating of manure will also
reduce the bacteria in manure.
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On-farm control of bacteria
Proper composting to reduce pathogens
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On-farm control of bacteria
Minimize recycling of water from lagoons into
housing areas.
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On-farm control of bacteria
Irrigate fields with lagoon water long before
forage crops are harvested. Use well water when
possible.
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On-farm control of bacteria
Dont recycle lagoon water in the sprinkler wash
pens
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On-farm control of bacteria
Avoid recycling lagoon water in housing areas
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On-farm control of bacteria
Protect water sources from manure
contamination. Clean, sanitize and chlorinate
frequently.
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On-farm control of bacteria
Reduce chances of contamination of feed
from rodents, birds, water or manure.
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On-farm control of bacteria
Proper handling and storage of manure.
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On-farm control of bacteria
Rodent Homes
Squirrel
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On-farm control of bacteria
Restrict entry onto dairy to prevent introduction
of new pathogens
Bacteria travel on people, animals and vehicles.
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On-farm control of bacteria
Veterinary herd health programs to reduce the
numbers of sick cows
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On-farm control of bacteria
Dont send sick animals to slaughter for beef.
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Moving and Storing Feeds

• Dont haul feed and manure in the same equipment.
  
• Clean the front loader that was used to haul dead
  calves prior to scooping a load of grain for the
  mixer wagon.

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Animal to Animal Transmission

• Isolation of sick animals is a good practice.
• No fresh cows in the sick pen.
• Quarantine new arrivals

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Transportation

• Transportation increases shedding in manure
• Hides become conta-minated by other cows feces.
  Contaminated hides are an important method of
  entry of pathogens into a slaughter plant

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At the Packing-House

• Pathogens can arrive via animals, equipment
  (trucks) and people
• Some plants wash cattle prior to slaughter
• Some plants use a sanitizer (or steam) to rinse
  carcasses
• Plants have practice procedures in place to
  sanitize equipment and protect carcasses
• Plants have procedures to reduce the spread of
  bacteria via employees

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Cancers as Biological Hazards

• The two major cancers that result in condemnation
  of cattle
• Cancer eye
• Lymphoma (from bovine leukemia virus)

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Cancer Eye

• Ocular squamous cell carcinoma
• Should be regarded malignant can be very
  destructive locally or
• Can spread to lymph nodes or organs
• Found in all breeds of cattle

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Cancer Eye

• Condemn When eye has been destroyed or obscured
  and evidence of spread beyond the head.

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Cancer Eye Carcass Is Condemned When It

• Involved bone of head
• Spread to any lymph node, organ, muscle, or other
  structures, and severe weight loss
• When carcass does not require condemnation, it
  may be passed for human food, after removal and
  condemnation of head including tongue.

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How to Prevent Condemnation Due to Cancer Eye

• Find them early when they are small, before they
  spread!
• If the tumors are just on one lid, they are easy
  to remove by your veterinarian and the cow will
  last longer in the herd

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Malignant Lymphoma

• Caused by Bovine Leukemia Virus infection
• Starts as lymph node swellings, bulging of eyes
• Can spread throughout the animals body

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Malignant Lymphoma
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Malignant Lymphoma

• Tumors in the heart

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Malignant Lymphoma

• Condemnation
• Of the carcass of any species with malignant
  lymphoma regardless of the degree of involvement

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What to do to Prevent Malignant Lymphoma?

• If you are having many condemnations due to
  lymphoma
• Discuss a possible control program with your
  veterinarian
• Change needles between cows to prevent spread of
  virus in blood
• Changing rectal sleeves between cows

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Other Conditions

• A key to understanding when an entire carcass may
  be condemned is the extent of the problem
• If the damage is extensive, often meaning
  involvement of more than one organ or tissue--the
  carcass is likely to be condemned!
• Bottom Line Make decisions before its too late!

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Septicemia/ Toxemia/ Pyemia

• These terms refer to signs seen at inspection
  that are associated with generalized disease
• The terms are usually reserved for use when signs
  are evident but the specific cause is unknown

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Septicemia/ Toxemia/ Pyemia

• Wide range of lesions that may be seen

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Septicemia/ Toxemia/ Pyemia

• Animals at before death that show any of the
  following signs could qualify
• Variable Temperature (high or subnormal)
• Injury or draining pus
• Downer or depression
• Reddening of skin

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Septicemia/ Toxemia/ Pyemia

• Animals before death that show
• Evidence of pain
• Muscle tremors
• Labored breathing
• Reddening of gums or around eyes
• Lameness

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Septicemia/ Toxemia/ Pyemia

• Postmortem findings that may lead to
  condemnation
• Infected wounds or bruises
• Generalized swollen lymph nodes
• Blood clotting problems

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Septicemia/ Toxemia/ Pyemia

• Postmortem findings that may lead to
  condemnation
• Hemorrhages
• Bloody fluid in the abdominal or thoracic cavity
• Recent injection site lesions
• Edema or other evidence of acute generalized
  inflammation

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Septicemia/ Toxemia/ Pyemia

• Specific Conditions may be treated as Septicemia/
  Toxemia/ Pyemia
• Extensive Pneumonia
• Extensive diarrhea
• Gangrenous Mastitis, etc.

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Hardware Disease

• Signs of Hardware
• Subcutaneous edema-brisket or lower abdomen
• Distension of jugular vein
• Tucked up abdomen
• Abnormal breathing
• Condemn when signs are generalized

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Downer Animals

• Downers will be condemned if
• Accompanied by signs of central nervous system
  disorder or disease
• Presented in a dying condition
• All comatose or semicomatose conditions or any
  conditions that would preclude release of the
  animal for human food

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Biological Hazards Risk Reduction

• Herd health program
• Treat early
• Cull early dont ship sick cows
• Good farm practices to reduce manure
  contamination
• Consult with packer when in doubt about what to
  ship