The California Mastitis Test (CMT) is a simple indicator of the Somatic Cell Count (SCC) of milk. It works by using a reagent which disrupts the cell membrane of somatic cells present in the milk sample; the DNA in those cells to reacting with the test reagent. It is a simple but very useful technique for detecting subclinical mastitis on-farm, providing an immediate result. It is not a replacement for individual laboratory cell count sampling, but has several important uses.
The reaction is scored on a scale of 0 (the mixture remaining unchanged) to 3 (an almost-solid gel forming), with a score of 2 or 3 being considered a positive result. This result is not a numerical result but is an indication as to whether the cell count is high or low; the CMT will only show changes in cell counts above 300,000.
The advantage of the CMT over individual cow cell count results is that it assesses the level of infection of individual quarters rather than providing an overall udder result, enabling the problem quarter(s) to be identified. It also provides a 'real-time' result; laboratory testing provides a historical result as it can take days for lab results to be returned.
One litre test liquid (sufficient for 500 quarters).