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Bulk milk bacteriology is a useful tool for investigations of mastitis (clinical and subclinical) and high bulk milk bacterial counts (“Bactoscan” or “TBC/TVC”).

Bulk milk bacteriology is a useful tool for investigations of [[mastitis]] (clinical and subclinical) and high bulk milk bacterial counts (“[[Bactoscan]]” or “TBC/TVC”).

==How to take a bulk milk sample==

==How to take a bulk milk sample==

Compared to taking an individual milk sample from a cow with mastitis, bulk milk samples are much more prone to bacterial overgrowth which can significantly affect the interpretation of the results. It is crucial that samples are kept cool immediately after being taken. This should involve the use of ice packs and an insulated box, especially if the sample has to be posted to the laboratory.

Compared to taking an individual milk sample from a cow with mastitis, bulk milk samples are much more prone to bacterial overgrowth which can significantly affect the interpretation of the results. It is crucial that samples are kept cool immediately after being taken. This should involve the use of ice packs and an insulated box, especially if the sample has to be posted to the laboratory.

An alternative to taking a sample yourself is to ask National Milk Laboratories (NML) to do it for you – a test known as a “Bacto-Breakdown”- if the farmer is provided with this service. This can be requested when the laboratory takes their weekly sample for milk fat, protein, SCC and Bactoscan tests. In fact, they can be asked to do it only if the Bactoscan is raised to a certain level in order to maximise the chance of getting a satisfactory result. Alternatively samples can be frozen on the farm when a Bactoscan reading is due. If the Bactoscan comes back high, then a bulk milk bacteriology can be performed. Some bacteria will die off due to the freezing but if the Bactoscan is suitably high, this is unlikely to significantly affect the interpretation of the result.

An alternative to taking a sample yourself is to ask National Milk Laboratories (NML) to do it for you – a test known as a “Bacto-Breakdown”- if the farmer is provided with this service. This can be requested when the laboratory takes their weekly sample for milk fat, protein, somatic cell count (SCC) and Bactoscan tests. In fact, they can be asked to do it only if the Bactoscan is raised to a certain level in order to maximise the chance of getting a satisfactory result. Alternatively samples can be frozen on the farm when a Bactoscan reading is due. If the Bactoscan comes back high, then a bulk milk bacteriology can be performed. Some bacteria will die off due to the freezing but if the Bactoscan is suitably high, this is unlikely to significantly affect the interpretation of the result.

==Interpretation==

==Interpretation==

===Coliform count===

===Coliform count===

The coliform count is reflective of the degree of faecal contamination of the teat and udder and therefore of parlour hygiene. High levels will be seen when the environment is poorly maintained in combination with minimal pre-milking trat preparation.

The coliform count is reflective of the degree of faecal contamination of the teat and udder and therefore of parlour hygiene. High levels will be seen when the environment is poorly maintained in combination with minimal pre-milking teat preparation.

===Detection of significant pathogens===  

===Detection of significant pathogens===  

Targets are available for most of the commonly found causes of subclinical mastitis (''S. aureus'', ''S. uberis''). However any ''S. agalactiae'' detected is a cause for concern and should prompt further investigation.

Targets are available for most of the commonly found causes of subclinical mastitis (''S. aureus'', ''S. uberis''). However, any ''S. agalactiae'' detected is a cause for concern and should prompt further investigation.

==Limitations==

==Limitations==

Blowey, R., Edmondson, P., 2010.''' Mastitis Control in Dairy Herds,''' 2nd Edition. ''CABI International.''

Blowey, R., Edmondson, P., 2010.''' Mastitis Control in Dairy Herds,''' 2nd Edition. ''CABI International.''

[[Category: To Do - Review]]

 

[[Category:Mastitis]]