What does a high bulk tank somatic cell count cost you?

Is your bulk tank somatic cell count (SCC) starting to creep up slightly? If so, don’t ignore it!

It is likely to be because the number of infected quarters in your herd is starting to increase a little, which in turn can lead to more infected quarters, and so on. Milk recording your cows regularly allows you to easily see what is happening within your herd. It is the best tool you have to establish which cows are the most profitable in your herd, while also identifying cows with a high SCC, indicating subclinical mastitis. Don’t assume that small bulk tank SCC increases during the summer will ‘settle down’- act now, and set your herd up for late lactation, with minimal mastitis infections and maximum milk production.
The financial impact of a ‘creeping’ SCC should not be underestimated. For example, at a milk price of 30c/L, if the average bulk tank SCC of a 100-cow herd increases from 150,000 cells/mL to 250,000 cells/mL, it reduces the overall farm profit by approx. €8,200. This reduction in potential profit increases to over €12,200 if the bulk tank SCC increases from 250,000 cells/mL to 350,000 cells/mL. This is huge money to be losing, especially in a year such as this where margins are tight.
 

What is a high SCC?
Any cow with an SCC of 200,000 cells/mL or higher on a milk recording, probably has at least one infected quarter. Depending on the type of pathogen she is infected with, it is very possible that she is a source of infection for other cows in the herd.
 

What can you do to minimise the problems caused by these infected cows?

1. Know who they are! This is where milk recording is essential, also providing reports that give an overview of the whole herd, highlighting the areas of good mastitis control and the areas that could be improved. If there are some parts of the report that you don’t understand, ask for help from your milk recording organisation, vet or advisor.

2. If you aren’t yet milk recording, use a CMT (paddle) to identity the infected cows and quarters.

3. These high SCC cows should be marked and milked last, or their cluster disinfected after milking to minimise disease spread.

4. Now is a good time to collect milk samples (at least 10) from problem cows and send to the lab for culture and susceptibility testing. Samples need to be collected as hygienically as possible or else the results will be misleading.

5. When you get these results back from the lab, discuss a suitable treatment plan with your veterinary practitioner - while treatment may appear to be the most logical option, remember that cure rates can range from 20-80% depending on various factors, such as the bacteria involved, the duration of infection and the cow’s lactation number.

6. Remove the source of infection -Dry off individual quarters i.e. simply stop milking it, do NOT use a dry cow tube. Consider culling if the cow is a problem cow i.e. high SCC in two consecutive lactations. These problem cows are not only costing you money, which is sometimes not apparent, but they can also be a source of infection for the healthy cows.

7. Continue to use post milking teat disinfection correctly, throughout lactation.

See Management Note M in the CellCheck Farm Guidelines (available here https://animalhealthireland.ie/programmes/cellcheck/farm-guidelines/) for advice on dealing with high SCC cows. The CellCheck Farm guidelines provide very useful advice during the various stages of lactation and are available on AHI website. A free veterinary consult is also available if you need help to get your mastitis under control. For more information visit the Cell Count Solutions TASAH webpage (https://animalhealthireland.ie/programmes/cellcheck/cellcheck-cell-count-solutions-tasah/).

First Published: 27 August 2024