Animal Health

Keep an open mind when investigating

By Rod Dyson

DURING THE milking process in any dairy, there are a substantial number of factors which can influence the risk of mastitis infections.

The Countdown Farm Guidelines and the supporting Countdown Technotes describe these factors very well, and also how to measure and assess them.

It takes a reasonable amount of time to conduct all the necessary assessments during milking, and it may not always be possible to complete all the tasks in one milking — especially if it is a relatively short milking or there is only one adviser conducting the assessment.

Having now done milking time assessments in literally hundreds of Australian dairies, it would be easy to generalise and assume that the most common risk factors are always likely to be there.

However, some recent milking time visits have reinforced for us how every dairy and every herd of cows is different, and also how important it is to enter each milking assessment with an open mind.

As an example, two of the most common risk factors that we see arising as a problem in these assessments are teat end condition and teat disinfection.

In terms of teat end condition, it is quite common for us to find over 40 per cent of teat ends with hyperkeratosis around the teat orifice that would be classified as either “rough” or “very rough” according to the definitions that Countdown has given us.

This means that over 40 per cent of quarters on those farms are at a significantly higher risk of infection due to this damage.

Compare that to a farm where teat end condition is very good with only 10 per cent of teat ends having hyperkeratosis that was classified as “rough” or “very rough”.

With significantly less teats adversely affected, this translates to a significant reduction in the overall risk to the herd.

With respect to teat disinfection, the importance of highly effective teat disinfection in mastitis control cannot be overstated.

In fact, the Countdown Farm Guidelines tell us quite clearly — “It is one of the most effective cell count and mastitis control measures available, but it only works if it is done thoroughly.”

Whilst “done thoroughly” involves a number of factors like product choice, mixing, storage, etc., probably the key element is the actual coverage of teats that is achieved upon application of the disinfectant.

It is very common for us to find that the coverage being achieved is much less than what it appears to be at first glance.

Often a little time spent observing cows leaving the platform will suggest significant areas of teats that have not been covered, especially the front of teats as this is the most difficult area to get to with the spray.

However, the “paper towel wrap-around test” is a definitive method by which stark differences in the coverage being achieved can be easily demonstrated.

In terms of the overall mastitis risk to the herd, the impact of these factors is often cumulative.

A herd with a high level of teat end damage that also has poor teat spray coverage will be at a far higher risk of mastitis infections than a herd with good teat end condition and excellent teat spray coverage.

Whilst we have discussed just these two risk factors, it actually then extends across all of the different factors that are assessed and measured during a milking time assessment, which can result in a complex set of findings that will need to be considered and prioritised.

Once prioritised, specific plans can then be made to address the key issues that have been discovered.

Countdown trained advisers have the tools to conduct these assessments for you, and you may well be surprised at what you discover!

• Rod Dyson is a veterinary surgeon and mastitis adviser at