Take time to understand mastitis and be rewarded with gains in animal health and productivity, says Lisa Whitfield.

Mastitis is a disease that is universally experienced on dairy farms. There is no farm that doesn’t have mastitis but there is wide variation between experiences on each farm from season to season.
Ask yourself if mastitis control is a priority for you.
It takes the investment of time, effort, and money to understand mastitis on an individual farm but the long-term gains in animal health and productivity are very rewarding.
Over the last six years I have been privileged to have worked with a number of farmers who have been successful in lowering their bulk tank somatic cell counts and clinical mastitis rates.
Some of the lessons they have learned, which they felt made a difference to their operations, are discussed here:


You may know everything that is important to running a smooth operation in the shed, but do your staff have the same knowledge? It is important that everyone involved in the milking process knows the fundamentals about mastitis.
Ensuring a good baseline level of knowledge among your staff will start you off on the right foot when it comes to tackling mastitis. The actions of people on the farm are one of the biggest contributors to mastitis problems, so you have to invest the time into getting everyone on the same page.
Do they take note of the cow that is slow to walk out of the paddock? Do they strip and paddle that quarter that is swollen at cups-off? Do they know how to do teat spraying properly? Are they careful with where they use wash hoses during milking? Do they know how to take a milk sample for culturing?
Machine function and maintenance of its components is a given to most people; however, it is still surprising how often the milking machine is not working correctly and problems haven’t been addressed. Make sure the rubberware is changed on time and don’t crank vacuum levels up unnecessarily.


Which mastitis-causing bacteria are a problem on your farm? If you can’t answer this, how do you know where to focus your efforts to make a change?
Mastitis pathogens all come from many different sources to cause inflammation in the udder, increasing cell counts and causing clinical cases.
For example, Streptococcus uberis is sourced from the environment, particularly from cow faeces; Staphylococcus aureus is sourced from the udder of cows, so contamination comes from infected milk; Corynebacterium bovis resides on cow skin, particularly on teat skin.
If you know the type of bacteria that are causing your problems you can set up a targeted control plan that not only aims to reduce the level of infection but also is focussed on stopping cows from picking up new infections from the source.
Find the way that works for you to monitor the bacterial pathogens on your farm.
Make sure you don’t scrimp on milk sampling – take enough samples to give you a good handle on your situation. Learn how to take clean, uncontaminated milk samples so you don’t waste your time and money.


Healthy teats and udders are the first line of defence against mastitis. If you have teat damage you are leaving an open door for bacteria to invade and colonise the teats and udder.
Some practical tips for healthy teats and udders include:

  • Teatspray – this should be applied shortly after cups-off at every milking for the whole season. Emollient is a really important part of teat health as it moisturises the skin, keeping it from drying out and cracking. Dry, cracked skin provides a haven for bacteria such as Corynebacterium to colonise the teat skin and subsequently the teat canal, which will result in elevations in cell counts.
  • Minimise overmilking – leaving the cups on the cows after they have finished milking out is an easy way to damage teats. Once a cow has milked out, cups should be removed as soon as possible – the average overmilking time should be less than 90 seconds per cow.
  • Internal teat sealants – these should be used in every cow at the end of lactation. They provide the best protection against new udder infections being acquired over the dry period. It is critical that they are applied correctly – plan, don’t rush the job, and get in help if you need it.

Mastitis is a vast subject but it doesn’t have to be complicated. People have the biggest impact on mastitis levels on the farm, and understanding what you do to influence this is a step towards understanding how you can break the cycle of infection on the farm.

Lisa Whitfield is a Manawatu Production Animal Veterinarian.