References
CPD article: The California mastitis test: what is the value?
Abstract
The California mastitis test is a widely used cow-side test for the detection of subclinical mastitis in dairy cows. It is easy and cheap to perform on farm, with its use therefore widespread around the world. The test is performed by adding a reagent to a milk sample, agitating the sample and then evaluating the reaction by using a recognised scoring system. Each quarter of an udder is tested by drawing milk into a paddle where the test can be performed. The test can also be performed in other ways, such as on a composite sample or through in-line testing in a milking parlour or automated milking system. The threshold of the test is approximately 400 000 cells/ml. This makes the test useful for determining the infected quarter following a high somatic cell count composite test result, diagnosing subclinical mastitis in a quarter at dry off or assisting with the diagnosis of clinical mastitis, eg in a toxic cow. The limitations of the test are that it is not quantitative, there is variability in operator interpretation and the exact threshold of detection is not known for each testing method. Overall, the test may be a valuable addition to cow-side mastitis diagnosis when used in the appropriate circumstances.
The California mastitis test (CMT) is a cow-side milk test to detect the presence of subclinical mastitis. It is commonly used in the milking parlour to detect changes in the milk that are not visible to the naked eye. The test can be easily performed by a farmer or herdsman and gives a rapid result that allows a decision to be made about the milk hygiene before it enters the bulk tank. Standardisation of the test was published in the early 1960s to prevent confusion and misinterpretation of the test and this is still followed to the present day. At present the CMT is the only available cheap cow-side test for diagnosing the presence of infection in individual quarters. It is therefore widely used worldwide.
Milk is drawn from each quarter of the udder into a corresponding well in the paddle (Figure 1). Excess milk is drained away by tilting the paddle until approximately 3 ml of milk is left in each well, a graduated line on the rim of the wells denotes the level to drain to (Figure 2).
Register now to continue reading
Thank you for visiting UK-VET Companion Animal and reading some of our peer-reviewed content for veterinary professionals. To continue reading this article, please register today.