Transcript BULK TANK MILK ANALYSIS Diagnostic Tools and Applications to

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
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Introduction
To 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.
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Bulk Tank Milk Analysis:
FUNDAMENTALS
A systematic approach to analyzing
BTM to assess raw milk quality and
herd udder health
Total bacteria
ONE
Identify the issue
 Milk Quality?
X 1000
60
Low or no premiums due to high
bacterial counts
Trouble shoot persistent high
bacterial counts
Monitor herd health after
expansion
Education of milkers
50
40
30
20
10
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MayAug
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A systematic approach to analyzing BTM to assess raw
milk quality and herd udder health
Identify the issue
Mastitis?
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 ?
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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
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What’s wrong with these pictures ???
No ! Nein ! Nem ! Nyet !
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 Laboratories
 Private Laboratories
 Bacteriological Quality of Milk
 American Public Health Association (SMEDP)
 Milk Cooperative testing facilities
 State Diagnostic Laboratories
 Private Laboratories
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Suggested guidelines for monitoring BTM
Counts
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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
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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 Loss
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Somatic 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
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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 500,000600,000 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/ml
Coliforms: <300,000 cells/ml
Non-coliforms: No data
Milking Procedures:
No established milking protocol
Milking 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 cleaned
Milking done on wet teats, or cloth towels reused without cleaning
Farm Hygiene
Poor bedding or alley/ manure management
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Standard Plate Count
Rating based on cfu/ml
SPC of <1000 cfu /ml is an
Good Acceptable Concern
(low)
(medium)
( high)
<5,000 <10,000
>10,000
20000
18000
16000
14000
12000
10000
8000
6000
4000
2000
0
indication that milk is from
clean and healthy cows
SPC of less than 5000 cfu/ml
< 5,000
can be achieved
< 10,000
> 10,000
SPC of <10,000 can be
achieved by most farms
< 5,000
< 10,000
> 10,000
Standard Plate Count
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SPC
Count
ideal
<10,000
4/1
1,320
4/4
29,040
4/8
7,360
4/12
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•Failure of water heater
•New Milkers
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Most probable reasons for high SPC
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
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Preliminary Incubation Count
Rating based on cfu/ml
Good
(low)
<10,000
90,000
80,000
70,000
60,000
50,000
40,000
30,000
20,000
10,000
0
Acceptable Concern
(medium) ( high)
<20,000 >20,000
< 10,000
< 50,000
> 50,000
< 10,000
< 50,000
> 50,000
Preliminary Incubation Count
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PIC
Count
ideal
<10,000
4/1
1,600
4/4
64,000
•Failure of water heater
4/8
14,800
•New Milkers
4/12
2,000
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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
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Unclean milking equipment ?
LPC
Rating based on cfu/ml
Good Acceptable Concern
(low)
<100
(medium)
<100- 200
( high)
250
200
Leaky pumps, deteriorated pipe
line gaskets, inflations and
other rubber parts, and
milkstone deposits
< 100
< 100-200
> 200
Extremely dirty cows ?
150
100
Significant levels of
contamination from soiled cows
can also contribute to high LPC
50
0
Faulty milking machine or worn
out parts ?
> 200
350
300
High LPC is most often seen
with persistent cleaning
problems
< 100
< 100-200
> 200
Laboratory Pasteurization Count
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LPC
Count
ideal
<100
4/1
10
4/4
20
4/8
0
4/12
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Coliforms
Rating based on cfu/ml
Coliform counts >50
cfu/ml suggest:
1. Poor milking practices
Good
Acceptable
Concern
(low)
(medium)
( high)
2. Dirty equipment
>50
3. Contaminated water
<10
<50
160
140
< 10
< 50
> 50
120
100
4. Dirty milking facilities
5. Cows with mastitis?
80
60
40
6. Manure?
20
0
< 10
< 50
> 50
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
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Putting it all together !
SPC > 10,000
BTSCC > 200,000
BTSCC < 200,000
PI <10,000
PI >10,000
PI <10,000
PI >10,000
Milking practices
+++
+++++
++++
Cleaning
++
++++
++
++++
Cooling
+++
+++
++
++++
Mastitis
++++
+++++
++
++
+++++
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