Measuring somatic cell counts will help you improve milk quality and alert you to the early signs of mastitis in your herd. Regular somatic cell count checks will allow you to quickly identify and treat infected animals and protect your herd health and milk quality by preventing the spread of bacteria.
What are Somatic Cell Counts?
A somatic cell count is an indicator of milk quality. Somatic cells are natural immune cells that are always present in milk. They are mainly made up of white blood cells called leukocytes, which increase in response to the bacteria that cause mastitis. A somatic cell count is quantified as the number of somatic cells per millilitre (mL) of milk., and is normally reported in units of thousands of cells/mL of milk.
What Causes a High Somatic Cell Count?
The somatic cell count of milk increases when a cow’s immune cells are released into the milk to fight against pathogenic bacteria like Staphylococcus aureus, which causes mastitis. Generally, the higher the somatic cell count, the worse the infection is. However, somatic cell count can remain high for several weeks once an infection has cleared. Conversely, some pathogens can remain in the udder in a dormant state after the somatic cell count declines, only to flare up again, causing cyclical increases in somatic cell count.
Somatic Cell Count Thresholds
Most dairy contracts outline the somatic cell count thresholds that will earn farmers bonuses or result in penalties. These thresholds can vary between dairy companies and geographical regions. The generally accepted threshold for a healthy cow is up to 100,000 somatic cells/mL of milk. The generally accepted indicator of mastitis is 200,000 cells/mL of milk, with higher cell counts used as an indicator of the severity of infection. In the European Union if the somatic cell count in milk reaches 400,000 cells/mL it is deemed to be unfit for human consumption.
Early Mastitis Detection
Measuring somatic cell counts is one of the best ways to detect sub-clinical mastitis. Cows with sub-clinical mastitis show no physical signs of infection. They can be harbouring a potentially contagious infection even if their mammary glands and milk appear normal. Regular measuring of individual cow somatic cell counts will enable mastitis to be detected early and action to be taken to prevent sub-clinical mastitis from spreading undetected through your herd and affecting herd production and milk quality. The recommended actions to be taken when sub-clinical mastitis is detected are outlined in this article: Mastitis in Cows – Causes, Detection and Treatment
Target Treatments to Only the Animals That Need It
Measuring somatic cell counts can help you be much more selective with treatment, particularly if you are measuring the somatic cell counts of individual animals. Being able to monitor the somatic cell counts of individual cows over time will allow you to determine, in consultation with your veterinarian, which cows may need antibiotic or dry cow therapy, and which should remain healthy without it. This will allow you to limit antibiotic use in your herd and reduce costs.
Optimise Milk Quality
Measuring somatic cell counts can help you achieve and maintain high milk quality in your herd by identifying infected animals that need to be treated or culled. It will also allow you to exclude infected milk from your vat to avoid the quality of your bulk tank milk from being affected,. which will reduce the likelihood of penalties.
High Bulk Milk Somatic Cell Counts Can Be Costly
It only takes few infected animals to increase the bulk milk somatic cell count, especially if you have a small herd. A high bulk milk somatic cell count can lead to penalties from your dairy company and a lower pay out.
High Somatic Cell Counts = Lower Production
Milk yields tend to decline when somatic cell count increases. This can be a result of incomplete milking of the infected quarter(s) due to discomfort or blockages, or damage to milk secreting tissue caused by the infection. Therefore, cows with high somatic cell counts generally produce less milk than cows with lower counts. Their compromised immune system may also affect their fertility.
Individual Cow Somatic Cell Counts Important
Measuring individual cow somatic cell counts will enable you to monitor the udder health of each cow over a lactation and identify which ones may need dry cow treatment or culling. It will also help you determine how widespread the potential infection is within your herd and if it is caused by several cows with elevated counts or a small number with very high counts. Rising somatic cell counts need to be spotted early so the infected cows can be quickly identified and separated from the main herd. This will help prevent the infection from spreading, stop the milk from being affected, and provide some time to find the underlying cause of infection.
Somatic Cell Counts are Variable
Somatic Cell Counts in individual cows can be highly variable, with tests producing different somatic cell counts depending on when they are taken. Typically, if you milk twice a day, afternoon somatic cell counts will be slightly higher than morning counts due to the shorter interval between milking. Somatic cell counts tend to be higher after calving when colostrum is produced, and then again towards the end of lactation as milk production falls and the udder tissue begins to regress. It is also important to be aware that high somatic cell counts can be a brief temporary increase even in a normally healthy animal, for which no action is needed. Conversely, the somatic cell count of infected animals often fluctuates between high and low during a mastitis episode, meaning that a low herd test result can be misleading. The best way to manage this variability is to carry out regular monitoring.
Regular Monitoring will Give You the Best Picture
Monthly or less frequent somatic cell count monitoring may provide an inaccurate picture of an individual animal’s health, making it difficult for you to take the correct preventative action. For instance, a cow with a robust immune system may have a high milk somatic cell count when she is fighting an infection, but she could overcome the infection and return to normal somatic cell levels quite quickly. However, if her somatic cell count was measured in the height of the infection and decisions were made based on that particular reading, the cow may be unnecessarily treated with antibiotics, dried off or culled.
Real Time Frequent Data is Important
Up-to-date data will help you make better and quicker decisions about treatment, drying off and culling. Regular somatic cell count monitoring of individual animals will allow you to detect infections much earlier and take preventive measures if needed, without having to strip the whole herd. When making mastitis management decisions, the most recent laboratory-based herd test somatic cell counts available will be at best a few days old and at worst several months old, depending on when the last herd test was carried out.
Automated Somatic Cell Count Sensors
Automated electronic somatic cell count sensors are available for use in the parlour, as part of your regular milking routine. Automated sensors such as Saber SCC provide quick and accurate real time somatic cell count data for individual animals within minutes of cupping. A standard installation comprises sensors at one in every four milking points, providing weekly up-to-date data for almost the entire herd and approximately 150 tests per lactation for every cow. The results and any alerts from the sensors can be viewed on your device of choice to help you make real-time herd decisions and better manage mastitis and bulk somatic cell count levels.
The Saber Advantage
You can read more about Saber SCC to determine if it is right for your dairy farm here: www.saberfarm.com/products/saber-scc/