The majority of dairy farms are now in the depths of the calving season, but a focus needs to be placed on cell counts.

A milk recording is the best way of getting the full picture of what is happening within your herd, but a California mastitis test (CMT) is a way of getting real time information on individual cows.

Performing a CMT will give you an accurate judgement of whether a cow has a high or low cell count after calving.

This can be used to determine if a cow has cured over the dry period or not. What the CMT does not provide you with, is the actual cell count level from the cow.

Cell counts

As a herd returns to lactation, it is important that you focus on controlling cell counts within your herd.

In many herds, cows will have received no antibiotic treatment at drying off.

Once a cow calves and starts to enter into the bulk tank, you should complete a CMT on each cow.

If a high reading is detected, you can take a sample from the cow to get it tested and determine what bacteria is the issue.

A treatment can then be given, and this cow can be monitored over the coming months to determine if she has been cured.

Once sufficient cows have calved, you should begin to look at completing a milk recording and complete this with the CMT you have completed – along with the data from last year.

This information is vital for ensuring that infected cows are removed from the herd and cell counts within the herd are kept under control.


A CMT is a quick and effective way of monitoring cows, and offers real-time information on cows.

The procedure for using the CMT kit is very simple:

  1. Draw and discard the first three draws and then fill each well with a quantity of milk. Try to avoid cross contamination;
  2. Once all four wells have a quantity of milk, tilt the tray to a 45º angle – this will ensure there is an equal volume of milk in all four wells;
  3. Turn the tray back flat and squeeze the bottle until an equal quantity is applied to all four wells; there should be an approx. 50:50 mix of milk and reagent;
  4. Stir the tray for 30 seconds and watch for any changes to the consistency of the solution. The degree of thickness reflects how high the SCC level is within the quarter.

The test should be carried out prior to attaching clusters.


During early lactation, cows are going to be both on cubicles and at grass, so good hygiene is important.

Keeping cubicles dry and clean is vital, as doing so will ensure that infections are not picked up in early lactation.

You also need to look at your milking routine to ensure that you are not a potential source of infection for cows.

Early cases of mastitis can be detrimental to a cows lactation and reduce the overall production from the lactation.

Focus on the management practices pre and post calving that will help stop cows from picking up infections, and then stop the spread.