How To Test For Mastitis Using CMT Method (California Mastitis Test)
Mastitis is a common yet costly issue for dairy farmers, characterized by the inflammation of the udder, often caused by bacterial infections. Detecting mastitis early is crucial to maintain milk quality, protect animal health, and prevent economic losses. One of the most effective and simple methods for detecting subclinical mastitis is the California Mastitis Test (CMT).
What is the California Mastitis Test?
The CMT is a cow-side test that identifies the presence of somatic cells in milk, which increase in response to infection in the udder. The test is widely used because it is quick, affordable, and easy to perform without specialized equipment.
Why Test for Mastitis?
Early Detection: Identifies subclinical mastitis (no visible symptoms), which can progress to clinical mastitis if untreated.
Milk Quality Control: Prevents contaminated milk from entering the food supply.
Cost Reduction: Reduces treatment costs and prevents losses from discarded milk or decreased production.
Improved Herd Health: Enables targeted treatment and management of affected cows.
How to Perform the CMT
The test requires a CMT paddle (a four-well plastic paddle), CMT reagent, and milk samples from each quarter of the udder.
Collect the Milk Samples
Clean the teats thoroughly with a sanitizing solution and dry with a clean towel.
Discard the first few streams of milk to remove contaminants from the teat canal.
Express about 2 mL of milk from each quarter into the corresponding well of the CMT paddle.
Add the CMT Reagent
Add an equal volume of CMT reagent to the milk in each well.
Swirl the paddle gently in a circular motion for about 10 seconds to mix the milk and reagent.
Observe the Reaction
Look for changes in the consistency of the mixture.
The presence of somatic cells will cause the milk to form a gel-like substance.
Interpreting the Results
The CMT reaction is graded based on the degree of gel formation:
Negative (-): No reaction; milk remains liquid.
Trace (T): Slight thickening; subclinical mastitis may be present.
Weak Positive (+): Gel formation; infection likely.
Strong Positive (++/+++): Thick gel or clumps; indicates high somatic cell count and likely infection.
Tips for Accurate Testing
Use a clean paddle and fresh reagent for every test.
Test milk at body temperature for consistent results.
Follow up positive tests with laboratory cultures for pathogen identification and treatment planning.
Post-Test Actions
For Positive Results: Consult a veterinarian for treatment recommendations, including antibiotics or alternative therapies. Isolate infected cows to prevent spreading the infection.
For Negative Results: Maintain good milking hygiene and udder health practices to prevent future infections.
The California Mastitis Test is an invaluable tool for dairy farmers to detect mastitis early and maintain herd health. Regular testing, combined with proper hygiene and management, can significantly reduce mastitis cases, improving milk quality and boosting farm profitability. By integrating the CMT method into your herd management routine, you ensure healthier cows and a more productive dairy operation.
Remember: Healthy udders produce healthy milk, so invest in testing for the best outcomes!
