bulk tank milk analysis - a tool for troubleshooting mastitis and milk quality problems in dairy...

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


IntroductionTo assure milk quality

----bulk tank milk periodically tested for

Antibiotic residues

Total number of bacteria

Somatic cells


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 !!!!!!!!


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


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


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


TWO

When to collect ?

After 1-2 h of milking

Milk should preferably represent one milking


Select the right containers for shipping bulk tank milk

No ! Nein ! Nem ! Nyet !

YES !


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 !


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


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


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


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


Somatic Cells

SCC Count

ideal 200,000

4/1 141,000

4/4 225,000

4/8 173,000

4/12 325,000


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


Contagious Mastitis Pathogens

S.aureus Strep.ag. Mycoplasma

ideal 0/4 0/4 0/4

4/1 + - -

4/4 - - -

4/8 + - -

4/12 + - -


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).


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


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


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



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


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


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




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


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




<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


Laboratory Pasteurization Count

LPC Count

ideal <100

4/1 10

4/4 20

4/8 0

4/12 0




<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


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

bulk tank milk analysis - a tool for troubleshooting mastitis and milk quality problems in dairy...

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