Somatic cell count measures the number of somatic cells in milk, serving as a vital signal of udder health in dairy cows. Scientists note that higher somatic cell count in dairy production often points to infection or inflammation, such as mastitis, which can lower milk quality and threaten hygiene. Dairy producers rely on regular monitoring because persistent increases in somatic cell count lead to reduced yields and economic loss. Modern technologies now help dairy producers track herd health more precisely, supporting better outcomes for both cows and consumers.
Key Takeaways
Somatic cell count shows the health of a cow’s udder and helps detect infections like mastitis early.
High somatic cell count lowers milk quality, reduces milk yield, and can cause bad taste and shorter shelf life.
Regular testing and good milking routines help keep somatic cell count low and protect milk safety.
Proper equipment care and clean bedding reduce infections and improve udder health.
Tracking somatic cell count data helps farmers make smart decisions and increase farm profits.
Somatic Cell Count in Dairy Production
What Is Somatic Cell Count?
Somatic cell count in dairy production refers to the number of somatic cells per milliliter of milk. These cells include macrophages, polymorphonuclear leukocytes, lymphocytes, and epithelial cells. Dairy cows produce these cells as part of their immune response. When the udder faces infection or inflammation, such as mastitis, the number of somatic cells rises. Scientists usesomatic cell count to measure the physiological health of dairy cows and the quality of milk. Milk somatic cells play a vital role in defending the mammary gland against pathogens. High somatic cell count signals an immune reaction and often points to underlying health issues in the herd.
Why SCC Matters?
Somatic cell count acts as a primary indicator of udder health and milk hygiene. Researchers have shown that measuring somatic cell count in dairy production helps detect invisible mastitis and monitor herd health. Elevated somatic cell count in dairy cows links directly to reduced milk yield, changes in milk composition, and increased risk of spoilage. High levels also mean more proteolytic enzyme activity, which can damage milk proteins and affect cheese production. Dairy producers rely on somatic cell count to identify cows at risk and maintain milk safety.
Monitoring somatic cell count in dairy production supports early detection of infection and helps prevent economic losses.
Bulk tank SCC above 200,000 signals subclinical mastitis; 500,000 SCC linked to 16% infected quarters and 6% milk loss.
Brazil
1,000,000
Grade A milk standards include max SCC of 1,000,000 cells/mL for safety and quality.
Dairy producers use these thresholds to guide herd management and ensure milk hygiene. Somatic cell count in dairy production remains a key factor in producing safe, high-quality milk.
SCC and Milk Hygiene
Udder Health and Infection
Somatic cell count serves as a reliable marker for udder health in dairy cows. When the udder becomes infected, the immune system responds by sending more somatic cells, mainly immune cells, into the milk. Infected mammary quarters show much higher somatic cell counts than healthy ones. The average somatic cell count in infected quarters can range from about 66,000 to 338,000 cells per milliliter, depending on the bacteria involved. Rear quarters often have higher somatic cell counts and infection rates than front quarters. Older cows, cows with more lactations, and those in early lactation tend to have both higher somatic cell counts and more frequent infections. High-producing and crossbred dairy cows also face greater risks. This strong link between somatic cell count and intramammary infection highlights the importance of regular monitoring.
Mastitis, an inflammation of the mammary gland, stands as the main cause of increased somatic cell count in dairy cows. Bacterial infection triggers the immune response, leading to more immune cells in the milk. Even when cows show no visible symptoms, subclinical mastitis can still raise the somatic cell count above 200,000 cells per milliliter. Monitoring somatic cell count allows dairy producers to detect these hidden infections early. This approach helps maintain udder health and supports efforts in preventing mastitis.
Regular monitoring of somatic cell count helps dairy producers identify infections early and protect milk quality.
Mastitis and Microbial Risks
High somatic cell count in milk often signals poor hygiene and the presence of mastitis-causing bacteria. Mastitis not only increases somatic cell count but also raises the risk of microbial contamination in raw milk. Pathogens such as Staphylococcus aureus thrive in these conditions, leading to higher total bacterial counts. Coliform bacteria, which come from the cow’s environment and fecal matter, also increase when hygiene practices fall short. When coliform counts exceed 1,000 colony-forming units per milliliter, the risk of contamination from harmful bacteria like Escherichia coli O157:H7 rises.
Elevated somatic cell count links to:
Increased total bacterial counts in milk
Higher levels of coliform contamination
Greater risk of public health issues, especially where raw milk is consumed
Proper udder hygiene and careful milking routines play a key role in controlling somatic cell count and reducing microbial risks. Dairy producers who focus on clean equipment, healthy cows, and good milking practices help ensure safer milk for consumers. By keeping somatic cell count low, they protect both milk quality and public health, reducing the mastitis impact on their herds.
Impact on Milk Quality
Effects of High Somatic Cell Count
High somatic cell count in dairy cows leads to a noticeable drop in milk yield. Inflammation in the udder, often caused by bacterial infections, disrupts the normal function of the mammary gland. The immune response draws energy and nutrients away from milk production. Cows with elevated cell counts before drying off produce less milk after calving. This reduction becomes more severe when cows also suffer from mastitis, ketosis, or retained placenta. The inflammation process decreases lactose synthesis and suppresses prolactin, a hormone essential for milk production. As a result, both the quantity and quality of milk decline. Herds with lower somatic cell count consistently achieve higher yields and better efficiency. The energy that would support milk synthesis instead fuels the immune system’s response, further reducing output.
Changes in milk composition also occur. Milk from affected cows contains less lactose and protein. The decrease in these key nutrients lowers the nutritional value of the milk. These changes highlight the importance of managing udder health to maintain high-quality milk and optimal dairy product quality.
Changes in Taste and Shelf Life
Milk quality suffers when somatic cell levels rise above recommended thresholds. The milk’s composition shifts, with reductions in fat, lactose, casein, and potassium. At the same time, levels of whey protein, lactoferrin, sodium, and chloride increase. Enzymes released by immune cells, such as lipases and proteases, break down milk fat and protein. This process leads to off-flavors, including rancidity, saltiness, and bitterness.
Milk with high cell counts often tastes unpleasant and fails to meet consumer expectations.
The breakdown of fats and proteins not only affects flavor but also shortens shelf life. Milk with elevated cell counts spoils faster, even after pasteurization. Quality deterioration can appear within two to three weeks of refrigerated storage. In contrast, high-quality milk from healthy cows maintains its sensory appeal and freshness for a longer period. These changes make it difficult for processors to produce cheese and other dairy products with consistent quality. Reduced coagulation ability and increased lipolysis further lower cheese yield and processing efficiency.
Economic Impact
High somatic cell counts create significant economic challenges for both farmers and processors. The most substantial losses come from decreased milk production. Lower yields mean less product to sell, which directly reduces farm income. Quality premiums, which reward farmers for producing milk with low somatic cell count, become harder to achieve. Processors prefer milk with fewer somatic cells because it lasts longer and produces better cheese.
Annual economic losses from subclinical mastitis can reach millions in some regions.
About 93% of these losses result from reduced milk yield, while the rest come from lost quality premiums.
Veterinary and treatment costs rise due to increased mastitis cases.
Milk with lower somatic cell count gains access to premium markets and organic certification, leading to higher prices and better contracts.
The invisible costs of high cell counts—lost income, higher expenses, and missed opportunities—add up quickly.
Maintaining udder health and monitoring cell counts help dairy farmers protect their bottom line. By focusing on milk quality, they improve both product value and consumer trust in dairy products.
Monitoring Somatic Cell Count
Testing Methods
Dairy producers use several methods to measure somatic cell count in milk. Direct detection techniques, such as fluorescence photoelectric counting, Coulter counting, and flow cytometry, provide accurate and reproducible results. These methods require specialized equipment and trained personnel. The microscopic method remains the regulatory standard, but it can be complex and subject to bias. Indirect methods, including the California Mastitis Test (CMT), ATP bioluminescence detection, and conductivity or pH detection, offer simpler and more affordable options. However, these tests lack sensitivity and specificity. A new colorimetric approach, the OPD-Cu2+ system, shows promise for reliable and cost-effective SCC measurement.
Method Type
Methods
Advantages
Disadvantages
Direct Detection
Fluorescence photoelectric counting
Rapid, reproducible
Expensive, needs experts
Coulter counting
Fast detection
Complex sample prep
Flow cytometry
Efficient, accurate
High cost
Indirect Detection
California Mastitis Test (CMT)
Low cost, easy to use
Qualitative, subjective
ATP bioluminescence detection
Simple, quick
Low accuracy, interference
Conductivity and pH detection
Simple process
Needs microscopy for accuracy
Somatic Cell Count Tester
Somatic cell count tester has transformed SCC monitoring on dairy farms. The tester mixs milk samples with fluorescent stains and count cells using automated detection. The process reduces human error and improves repeatability compared to manual microscopic methods. Portable tester like somatic cell counter for milk deliver results in under a minute and show strong agreement with laboratory standards. Somatic cell count testeruse fluorescence to identify and count somatic cells, providing rapid and reliable data for herd management. Advanced models now connect wirelessly to herd management systems, allowing producers to track SCC trends and respond quickly to udder health issues.
Legal and industry standards for somatic cell count in milk vary worldwide. In the United States, the maximum allowed bulk tank scc is 750,000 cells per milliliter. Most U.S. farms already keep SCC well below this limit, with averages near 245,000 cells per milliliter. Many countries, including those in the European Union, Canada, and Australia, set stricter limits between 300,000 and 400,000 cells per milliliter. Regulatory agencies such as the FDA, USDA, and NCIMS monitor compliance through regular testing, inspections, and audits. These organizations enforce sanitation, equipment care, and record-keeping standards to ensure milk safety.
Country/Region
Legal Maximum Bulk Milk SCC (cells/mL)
European Union
300,000 – 400,000
China
300,000 – 400,000
New Zealand
300,000 – 400,000
Australia
300,000 – 400,000
Switzerland
300,000 – 400,000
Canada
300,000 – 400,000
South Africa
500,000
Brazil
500,000
United States
750,000
Practical Steps for Producers
Daily Routines
Dairy producers achieve lower somatic cell count by following consistent daily routines. They monitor somatic cell counts in dairy cows to identify health issues early. Culturing milk samples helps determine if infections are contagious or environmental. Producers often milk infected cows last and separate them from the herd. They apply effective teat dips, ensuring proper coverage and contact time. Clean, dry bedding supports udder health and limits bacterial growth. Employees clean teats before milking to remove dirt and manure. Reviewing herd reports allows producers to spot cows with high counts for possible treatment or culling. These routines support hygiene and prevention of mastitis.
Consistent milking routines and dry cow management directly reduce somatic cell count in dairy herds.
Producers face challenges such as bedding contamination, heat stress, and fly control. They overcome these by keeping bedding dry, using fans and sprinklers, and training staff on proper milking procedures. Forming a milk quality team and investigating infection patterns further strengthens daily management.
Equipment Care
Milking unit hygiene plays a vital role in controlling somatic cell count. Producers test and maintain milking equipment regularly to prevent teat end damage and udder infections. They replace milking machine liners on schedule, as worn liners can spread bacteria like Staphylococcus aureus. Routine maintenance checks with dairy suppliers help avoid equipment failures. Proper sanitation of milking equipment ensures that post-milking disinfection removes bacteria effectively. Producers add extra bedding on mattresses to improve cow comfort and reduce injuries, which also supports udder health.
Equipment Care Practice
Benefit for SCC Control
Regular equipment testing
Prevents improper milking, lowers SCC
Timely liner replacement
Reduces bacterial transmission
Thorough cleaning protocols
Maintains hygiene, limits infections
Maintenance checks with suppliers
Ensures optimal equipment function
Data Tracking
Producers track and analyze somatic cell count data to improve milk quality and farm profitability. They use sampling protocols like QualiTru’s inline system for effective surveillance. Regular tests such as the California Mastitis Test and Dairy Herd Improvement Association programs help monitor SCC trends. Technology supports consistent milk quality and reduces costs. Early detection of mastitis through representative sampling allows for timely intervention. Producers use decision-support tools to calculate the economic impact of SCC and make informed management choices.
Improving management practices through education and technology adoption is essential for SCC reduction and enhanced milk quality.
Conclusion
Monitoring and managing somatic cell count supports healthy herds and safe milk. Dairy producers benefit from regular SCC testing, which enables early detection of udder infections and helps maintain lower somatic cell count.
Weekly screening improves herd health and reduces financial losses.
Educational resources, such as workshops and online courses, provide practical skills for better management.
Ongoing education and adherence to best practices ensure sustainable dairy production and improved milk quality.
FAQ
What Is Considered a Healthy Somatic Cell Count In Milk?
A healthy somatic cell count in milk usually falls below 200,000 cells per milliliter. Dairy producers aim for this level to maintain udder health and ensure high milk quality.
How Often Should Dairy Producers Test Somatic Cell Count?
Producers typically test somatic cell count weekly or monthly. Frequent testing helps them detect infections early and maintain milk hygiene.
Can High Somatic Cell Count Affect Cheese Production?
High somatic cell count reduces cheese yield and quality. Enzymes from immune cells break down milk proteins, making cheese less firm and lowering processing efficiency.
What Are the Main Causes of Increased Somatic Cell Count?
Mastitis stands as the leading cause. Poor milking hygiene, dirty bedding, and equipment issues also contribute to higher somatic cell counts in dairy herds.
Are there Penalties for Exceeding Legal Somatic Cell Count Limits?
Yes, dairy producers may face financial penalties, milk rejection, or loss of quality premiums if somatic cell count exceeds legal limits set by regulatory agencies.
