bulk tank milk analysis - a tool for troubleshooting mastitis and milk quality problems in dairy...
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BULK TANK MILK ANALYSIS
- A Tool for Troubleshooting Mastitis
and Milk Quality Problems in Dairy
Herds
Bhushan Jayarao, MVSc, PhD, MPH
David Wolfgang, VMD, AABVP
Ernest Hovingh, DVM
Department of Veterinary and Biomedical Sciences
The Pennsylvania State University
MAC Conference-2006 2May 23, 2006
MAC Conference-2006 3May 23, 2006
IntroductionTo assure milk quality
----bulk tank milk periodically tested for
Antibiotic residues
Total number of bacteria
Somatic cells
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Why is BTM analysis attractive ?
Provides a view of current and potential problems in a herd
Less expensive than quarter milk sampling the whole herd
Less time to obtain results Rationale approach to troubleshoot herd
with multiple milk quality and mastitis related problems
A new approach to managing udder health !!!!!!!!
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Limitations of BTM analysis ?
Cannot extrapolate information to individual cow level.
For interpretation of results, 3 or more BTM samples required.
Information on herd management practices needed to interpret results
Samples must be held at 4oC and analyzed within 36 h of collection
Proper sample collection.
Interpretation more challenging on large herds.
Bulk Tank Milk Analysis:
FUNDAMENTALS
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A systematic approach to analyzing BTM to assess raw milk quality and herd udder health
ONEIdentify the issue
Milk Quality?Low or no premiums due to high
bacterial countsTrouble shoot persistent high
bacterial countsMonitor herd health after
expansionEducation of milkers
Aug Sep Oct Nov
60
50
40
30
20
10
Total bacteria
X 1000
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Identify the issueMastitis?
Consistently high SPC >20,000 ?BTSCC > 200,000 ?Increased incidence of clinical mastitis ?Troubleshoot high counts ?Buying a whole herd ?Low or no premiums ? Monitor after herd expansion ?Suspect Mycoplasma in herd ?
A systematic approach to analyzing BTM to assess raw
milk quality and herd udder health
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TWO
When to collect ?
After 1-2 h of milking
Milk should preferably represent one milking
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Select the right containers for shipping bulk tank milk
No ! Nein ! Nem ! Nyet !
YES !
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THREE
BTM samples
Agitate milk for 10 minutes
Collect 2 ounces of milk from the top of the bulk tank using
a clean sanitized dipper
Note temp on the bulk tank
Label the sample
Transport sample on ice
Sampling frequency High: 1 sample/ day for 4 days
Medium: 3 samples/ week for 2- 4 weeks
Low: 1 sample/ week for 4-8 weeks
What’s wrong with these pictures ???
No ! Nein ! Nem ! Nyet !
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FOUR
How to ship samples ? For Mastitis Pathogens
Freeze samples
For Bulk Tank Somatic Cell Count Samples must be shipped on ice containing the appropriate
preservative
For Mastitis pathogens and Somatic Cells Samples must be shipped on ice
For Milk Quality
DO NOT send samples frozen. Samples must be shipped on ice
Why ? Frozen samples do not give an accurate picture of
bacterial counts
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FIVE
Somatic Cell Count Mastitis pathogens
Staphylococcus aureus
Streptococcus agalactiae
Mycoplasma
Coagulase negative Staphylococci
Environmental Streptococci
Coliforms
Gram-negative non-coliform bacteria
Milk quality tests
Standard Plate Count
Preliminary Incubation Count
Laboratory Pasteurization Count
Coliform Count
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SIX
Somatic Cells Validated flow cytometric technique
DHIA or similar facility
Mastitis Pathogens NMC recommended protocols
State Diagnostic LaboratoriesPrivate Laboratories
Bacteriological Quality of Milk American Public Health Association (SMEDP)
Milk Cooperative testing facilitiesState Diagnostic LaboratoriesPrivate Laboratories
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Suggested guidelines for monitoring BTM
Counts Ideal
Bulk Tank Somatic Cell Count (BTSCC) <200,000 cells/ml
Standard Plate Count (SPC) <5,000 cfu/ml
Preliminary Incubation Count (PIC) <10,000 cfu/ml
Laboratory Pasteurization Count (LPC) <100 cfu/ml
Staphylococcus aureus (SA) Not detected (0/4)
Streptococcus agalactiae (SAG) Not detected (0/4)
Mycoplasma Not detected (0/4)
Coagulase Negative Staphylococci (CNS) <500 cfu/ml
Streptococci (SSLO) <500 cfu/ml
Coliforms (CC) <50 cfu/ml
Non-coliforms (NC) <200 cfu/ml
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Somatic Cells
SCC Count
ideal 200,000
4/1 141,000
4/4 225,000
4/8 173,000
4/12 325,000
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BTSCC and Production LossSomatic Cell Count Milk Production Loss (%)
100,000 0
200,000 2
300,000 4
400,000 6
500,000 8
600,000 10
700,000 12
800,000 14
900,000 16
1,000,000 18
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Contagious Mastitis Pathogens
S.aureus Strep.ag. Mycoplasma
ideal 0/4 0/4 0/4
4/1 + - -
4/4 - - -
4/8 + - -
4/12 + - -
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Contagious mastitis pathogens
Type of herd closed herd, suggests presence of chronic infection
open herd, suggests both the likelihood of newly purchased animals bringing in the
infection and chronically infected cows.
BTSCC High Staph. aureus isolation rate (3/4), BTSCC generally ranges from 350,000 -
1000,000 cells/ ml (most occasions 500,000- 600,000 cells/ml).
High Strep. agalactiae isolation rate (3/4), BTSCC generally ranges from 500,000-
600,000 cells/ml.
High Mycoplasma isolation rate (3/4), BTSCC variable (200,000- 800,000 cells/ml).
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Environmental Mastitis Pathogens
CNS SSLO Coliforms Non-coliforms
Ideal <500 <500 <50 <200
4/1 620 620 20 0
4/4 960 240 0 0
4/8 900 520 20 180
4/12 480 1,000 0 20
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Environmental Mastitis Pathogens
BTSCC:Streptococci and Strep-like organisms: 250,000- 450,000 cells/ml.CNS: 350,000 - 500,000 cells/mlColiforms: <300,000 cells/mlNon-coliforms: No data
Milking Procedures:No established milking protocolMilking procedures not consistent (varies from milker to milker and shift to shift)Poor udder surface (clipping or flaming not done)Teat and teat ends not thoroughly cleanedMilking done on wet teats, or cloth towels reused without cleaning
Farm HygienePoor bedding or alley/ manure management
Rating based on cfu/ml
Good Acceptable Concern (low) (medium) ( high)
<5,000 <10,000 >10,000
Standard Plate Count
02000400060008000
100001200014000160001800020000
< 5,000 < 10,000 > 10,000
< 5,000
< 10,000
> 10,000
SPC of <1000 cfu /ml is an
indication that milk is from
clean and healthy cows
SPC of less than 5000 cfu/ml
can be achieved
SPC of <10,000 can be
achieved by most farms
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Standard Plate Count
SPC Count
ideal <10,000
4/1 1,320
4/4 29,040
4/8 7,360
4/12 1,040
•Failure of water heater
•New Milkers
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Improper cleaning
Strep. agalactiae mastitis
Cows with soiled udders and teats, dirty equipment
New milkers?
Inability to cool milk rapidly to less than 4.4 C (40oF)
Failure of water heater
Failure in sanitation
Residual water in the lines
Extremely wet and humid weather/ milking conditions
Most probable reasons for high SPC
Rating based on cfu/ml
Good Acceptable Concern
(low) (medium) ( high)
<10,000 <20,000 >20,000
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
< 10,000 < 50,000 > 50,000
< 10,000
< 50,000
> 50,000
Preliminary Incubation Count
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Preliminary Incubation Count
PIC Count
ideal <10,000
4/1 1,600
4/4 64,000
4/8 14,800
4/12 2,000
•Failure of water heater
•New Milkers
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High PICs
A high PIC count suggests:
Cleaning and sanitation of the milking system
Poor udder preparation before milking
Failure to cool milk rapidly
Prolonged storage times
Milking cows with wet teats and teat ends
Extremely wet and humid conditions
Persistently high PIC counts may require identifying the organism
Rating based on cfu/ml
Good Acceptable Concern
(low) (medium) ( high)
<100 <100- 200 > 200
0
50
100
150
200
250
300
350
< 100 < 100-200 > 200
< 100
< 100-200
> 200
Unclean milking equipment ?
High LPC is most often seen with persistent cleaning problems
Faulty milking machine or worn out parts ?
Leaky pumps, deteriorated pipe line gaskets, inflations and other rubber parts, and milkstone deposits
Extremely dirty cows ?
Significant levels of contamination from soiled cows can also contribute to high LPC
LPC
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Laboratory Pasteurization Count
LPC Count
ideal <100
4/1 10
4/4 20
4/8 0
4/12 0
Rating based on cfu/ml
Good Acceptable Concern
(low) (medium) ( high)
<10 <50 >50
0
20
40
60
80
100
120
140
160
< 10 < 50 > 50
< 10
< 50
> 50
Coliform counts >50 cfu/ml suggest:
1. Poor milking practices
2. Dirty equipment
3. Contaminated water
4. Dirty milking facilities
5. Cows with mastitis?
6. Manure?
Coliforms
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Putting it all together !!!
50 ml or 2 ounces
Sterile 2 oz. snap cap vials, 50 ml tubes or whirlpack bags
Freeze sample when testing for mastitis pathogens
Refrigerate samples when testing for SCC and milk quality
Ship overnight perferably
Mention on the label Analyze for Milk Quality only
Analyze for Mastitis Only
Analyze for Milk Quality and Mastitis
Sampling frequency High: 1 sample/ day for 4 days
Medium: 3 samples/ week for 2- 4 weeks
Low: 1 sample/ week for 4-8 weeks
Putting it all together ! SPC > 10,000
BTSCC > 200,000
PI <10,000 PI >10,000
BTSCC < 200,000
Milking practices +++ +++++ ++++ +++++
Cleaning ++ ++++ ++ ++++
Cooling +++ +++ ++ ++++
Mastitis ++++ +++++ ++ ++
PI <10,000 PI >10,000
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