Managing Somatic Cell Count this spring
Elevated Somatic Cell Count (SCC) is a hidden cost on dairy farms. Unless a clinical case of mastitis is seen and treated, raised SCC levels are rarely acted upon. James Dunne, Teagasc dairy specialist, outlines the steps farmers should take to manage SCC in freshly-calved cows.
High SCC levels are costly, Teagasc research shows that mastitis costs Irish farmers €60/cow/year. This figure comes from sub-clinical costs – such as milk quality penalties, the loss of milk production along with clinical costs. Clinical costs would include antibiotics, discarded milk, labour, veterinary and culling.
Is the cow clear to enter the bulk tank?
A California Milk Test (CMT) on freshly-calved cows will identify sub-clinical cows; they can be milked separately (to avoid cross contamination to other cows). Their milk can be excluded from the bulk tank, and their infected quarters should be monitored and treated if necessary.
The California Mastitis Test (CMT) is a simple procedure to help identify the high SCC quarters within infected cows. It is impossible to identify sub-clinical mastitis in a quarter without this aid. The procedure is very simple, you should carry out the test prior to milking.
- Discard the first three draws from each teat and then fill each well with a quantity of milk, try to avoid cross contamination.
- Once all four wells have a quantity of milk, tilt the tray to a 45-degree angle. This will ensure there is an equal volume of milk in all four wells. Turn the tray back flat and squeeze the bottle until an equal quantity of reagent is applied to all four wells. There should be approx. 50:50 mix of milk and reagent.
- 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 and thus identifies the quarter(s) that have an infection.
- It is recommended if you are new to this process that you take a sample of milk into a sample bottle from each quarter, label these by quarter and wait until the end of milking before testing, when there is more time to analyse and record the results.
Identify the pathogen causing the sub-clinical mastitis
For cows that have been monitored post calving and aren’t improving, the next step should be to send a sample from the infected quarter(s) to a laboratory to identify the pathogen that is causing the elevated SCC. A sensitivity test will identify the offending pathogen and also identify the correct antibiotic to use as a treatment. Avoid contamination when collecting this sample from any dirt from the cows udder etc.
Treatment
Once sensitivity results are received back from the laboratory, a course of treatment can be discussed with your veterinary practitioner.
Preventing spread
Mastitis and some mastitis causing pathogens can be highly contagious and can spread in a variety of ways – from cow to cow in the parlour (through clusters) or on cubicles and from cow to cow via the person milking. Therefore, hygiene in the milking parlour and in cow housing is critical in managing SCC. Draw up standard operating procedures for persons milking on your farm.
Book your milk recording
It should be within the first 60 days after the start of calving to give the most accurate results of how successful the dry period was on your farm.