6 Best Somatic Cell Count Kits for Herd Health

You walk out to the barn and notice one of your best cows, Daisy, just isn’t herself. She ate a little slower, and her quarter felt a bit warm, but the milk looked fine. This is the moment every small farmer knows—the nagging feeling that something is off, and the hope that it’s nothing serious. Monitoring your herd’s health is less about reacting to big problems and more about catching the small ones, and that’s where on-farm somatic cell count (SCC) testing becomes one of your most powerful tools.

Disclosure: As an Amazon Associate, this site earns from qualifying purchases. Thank you!

Why On-Farm SCC Testing Matters for Your Herd

Somatic Cell Count, or SCC, is just a measure of the white blood cells in milk. A high count is a clear sign that a cow’s immune system is fighting an infection in her udder—usually subclinical mastitis. You might not see clumps or watery milk yet, but the battle is already happening inside.

Catching this early is everything on a small farm. It’s the difference between a simple intervention and a full-blown, costly infection that requires vet visits, antibiotics, and discarded milk. Regular SCC testing lets you identify problem cows before the infection spreads to others or impacts your bulk tank quality. It turns you from a reactive manager into a proactive one.

Think of it as a report card for each cow’s udder health. A consistently low SCC means a healthy, productive animal. A sudden spike is your early warning alarm, giving you time to investigate and act. This data helps you make smarter decisions about treatment, milking order, and even culling, protecting the long-term health and profitability of your entire herd.

Porta-Check CMT Kit for Rapid Mastitis Screening

The California Mastitis Test (CMT) is the classic, go-to screening tool for a reason. It’s simple, cheap, and gives you an answer in seconds. The kit is just a four-chambered paddle and a bottle of reagent. You squirt a little milk from each quarter into a chamber, add the reagent, swirl, and watch for a reaction.

The principle is straightforward: the reagent reacts with the DNA in somatic cells, causing the mixture to thicken or gel. No change means a low SCC. A slight thickening indicates a moderate count, and a gel-like clump means a high count and a likely infection. It doesn’t give you a specific number, but it’s incredibly effective at flagging a problem quarter on the spot.

This is the perfect starting point for any small farm. It’s not about precision; it’s about a quick, reliable "yes/no" answer to the question, "Is there inflammation here?" Use it to test a cow you’re suspicious of, check fresh cows, or do a monthly screen of the whole herd. Its value is in its simplicity and accessibility.

DeLaval Cell Counter DCC for Precise Readings

If the CMT paddle is a simple warning light, the DeLaval Cell Counter DCC is the full diagnostic dashboard. This handheld digital device gives you a precise SCC number in under a minute. It’s a serious step up in technology and provides the kind of data that allows for truly fine-tuned herd management.

The process involves a disposable cassette that you load with a milk sample. The device uses a camera and sophisticated software to physically count the cells and displays the result (e.g., 185,000 cells/mL) on a digital screen. This removes all the subjectivity of interpreting a CMT gel reaction. You know exactly what you’re dealing with.

The upfront cost is significant, and you have the ongoing expense of the cassettes. This isn’t for everyone. But if you’re selling milk where quality premiums are tied to low SCC, or if you’re managing a herd where tracking individual cow trends is critical for breeding and culling decisions, the investment can pay for itself. This tool is for the data-driven farmer who needs precision.

Draminski Mastitis Detector for Early Warning

This device works on a completely different principle. It doesn’t measure somatic cells at all. Instead, the Draminski Mastitis Detector measures the electrical conductivity of the milk, which is one of the very first physiological changes to occur during an udder infection.

When mastitis begins, salt levels in the milk rise, making it more conductive. You simply dip the probe into a milk sample, and the device gives you a reading. You’re not looking for a specific number but rather a difference between quarters. A healthy udder will have very similar readings across all four quarters; a significant deviation in one signals a problem, often days before the SCC even begins to climb.

The Draminski is an early warning system. It’s fantastic for catching subclinical mastitis at its absolute earliest stage. The downside is that it doesn’t confirm mastitis, it only flags a change. You’ll still want to follow up with a CMT or another test to confirm. But for staying ahead of problems, it’s a unique and powerful tool with no ongoing consumable costs.

Masti-Strip Test Strips for Individual Quarters

Think of these as the litmus paper of udder health. Masti-Strips are simple, disposable paper strips that measure the pH of milk. A healthy udder maintains a consistent milk pH, but an infection can cause it to become more alkaline.

Using them is as easy as it gets: you dip a strip into a milk sample from a single quarter and compare the color change to a chart. It’s a quick, inexpensive way to get a bit more information when you suspect an issue. They are especially handy for checking just one quarter without having to get out the whole CMT paddle and reagent.

However, like the Draminski, this is an indirect indicator. Other factors, like the stage of lactation, can also affect milk pH. They are generally considered less sensitive than a CMT for catching low-grade infections. Consider these a convenient, secondary tool for quick confirmation, not your primary screening method.

PortaSCC Quick Test for Accurate Farmside Counts

The PortaSCC Quick Test occupies a fantastic middle ground between the simple CMT paddle and an expensive digital counter. These tests use modern lateral flow technology—similar to a home pregnancy test—to give you a semi-quantitative SCC result right in the barn.

You typically mix a milk sample with a solution and then apply it to a test strip. After a few minutes, lines will appear on the strip. The number or intensity of the lines corresponds to a specific SCC range, such as "under 200,000," "200,000 to 400,000," and so on.

This is a huge improvement over the subjectivity of the CMT. It provides a numerical range that is far more useful for tracking a cow’s health over time or deciding on a treatment threshold. While there is a per-test cost, it’s a fraction of the investment for a digital reader. For the small farmer who wants better data than a CMT can offer without the high price tag of a digital device, this is the sweet spot.

ImmuCell CMT Test: A Reliable, Low-Cost Option

While we’ve discussed the CMT method, it’s worth highlighting a specific, reliable brand. The ImmuCell CMT kit is a workhorse in the industry. The paddle is durable, and more importantly, the reagent is consistent and produces clear, easy-to-read results. When you’re relying on a visual test, the quality of the reagent matters.

There’s not much to add that hasn’t been said about the CMT process itself. It’s fast, effective for screening, and incredibly cost-effective. Choosing a trusted brand like ImmuCell just ensures you’re getting a quality product that won’t leave you guessing. You can be confident that the reaction you’re seeing is a true reflection of what’s in the milk.

This is the foundational tool for herd health. Even if you invest in a more advanced system, you’ll likely always keep a CMT paddle on hand for quick checks. It’s the reliable, low-cost option that has proven its worth on farms of all sizes for decades.

Choosing the Right SCC Kit for Your Farm’s Needs

There is no single "best" kit; the right choice depends entirely on your goals, budget, and herd size. The key is to match the tool to your farm’s needs.

Here’s a simple framework to guide your decision:

• For the 1-3 Cow Homestead: A classic Porta-Check or ImmuCell CMT Kit is all you need. It’s affordable, effective, and will teach you to be a keen observer of your animals.
• For the Farmer Battling Hidden Infections: If you’re constantly dealing with surprise flare-ups, adding a Draminski Mastitis Detector can provide the early warning you need to get ahead of subclinical cases. Use it for screening, and confirm with a CMT.
• For the Growing Herd (5-15 cows) Wanting Better Data: The PortaSCC Quick Tests are your best bet. They offer a huge step up in data quality from a CMT without the major investment of a digital reader, allowing you to track trends and make better management decisions.
• For the Data-Driven Farmer or Raw Milk Producer: If you need precise numbers for quality control, premium payments, or intense genetic management, the DeLaval Cell Counter DCC is the right investment. The precision it offers is unmatched by other on-farm methods.

Don’t overcomplicate it. Start with a CMT. It’s the cornerstone of any mastitis detection program. Once you’re using it consistently, you’ll know if you need more data or an earlier warning system, and you can upgrade from there. The most important step is to start testing.

Ultimately, on-farm testing is about empowerment. It takes the guesswork out of managing udder health and puts actionable information directly into your hands, right when you need it. Knowing your numbers isn’t just about avoiding problems; it’s about building a more resilient, healthy, and productive herd for the long haul.

Frequently Asked Questions (FAQs)

What is an on-farm somatic cell count kit?

An on-farm somatic cell count kit is a diagnostic tool used to measure white blood cells in raw milk right inside the barn. These kits detect subclinical mastitis before visible clots or swelling appear in the udder. Farmers use either liquid reagent paddle tests like the California Mastitis Test or portable electronic readers to track individual quarter health. Routine testing helps producers isolate infected milk, lower bulk tank somatic cell counts, and qualify for milk quality premiums.

What somatic cell count score indicates subclinical mastitis in dairy cows?

A somatic cell count of 200,000 cells per milliliter or higher generally indicates subclinical mastitis in dairy cows. Uninfected mammary quarters usually produce milk with counts below 100,000 cells per milliliter. When bacteria enter the teat canal, the cow sends leukocytes to fight the infection, driving the count upward. If an individual cow reaches 400,000 cells per milliliter, significant milk yield loss occurs, and the milk should be cultured to identify the pathogen.

How do you use a California Mastitis Test somatic cell count kit?

Using a California Mastitis Test kit involves stripping milk into a four-well paddle, adding equal parts reagent, and swirling the mixture for twenty seconds. First, discard the foremilk and milk about two milliliters from each quarter into separate cups on the plastic paddle. Next, tilt the paddle to equalize the volumes, squirt in the purple CMT reagent, and rotate the tray in gentle circles. If the mixture thickens into a gel or changes color, elevated somatic cells are present in that specific quarter.

How long does a digital somatic cell count test take to show results?

Digital somatic cell count tests typically deliver numeric results in 45 seconds to 15 minutes, depending on the testing technology used. Handheld optical devices like the DeLaval DCC provide automated cell counts in under one minute per cassette. Lateral flow strip systems, such as PortaSCC, take about 45 minutes for milk strip incubation and enzymatic color development. Reading these tests during milking allows immediate separation of high-count milk from the cooling tank.

Are digital somatic cell counters better than chemical paddle test kits?

Chemical paddle test kits provide faster and cheaper screening, but digital somatic cell counters offer precise numerical data instead of subjective visual estimates. A California Mastitis paddle kit costs less than thirty dollars and shows qualitative gel formation within seconds at cowside. In contrast, digital readers cost between 1,000 and 3,500 dollars but report exact cell counts from 10,000 to over 4,000,000 cells per milliliter. Digital meters work best for tracking treatment progress, while paddle kits excel at quick daily screening.

How much does a somatic cell count kit cost per cow test?

Testing costs for a somatic cell count kit range from roughly 15 cents to four dollars per cow test. Standard liquid reagent paddle kits are the most economical option, averaging 15 to 30 cents per cow across four quarters. Enzymatic disposable test strips usually cost around two to three dollars per test strip. Automated optical cartridges for digital farm readers sit at the higher end, typically running between three and four dollars per sample cartridge.

Why does a somatic cell count test kit show a false positive?

False positive readings on a somatic cell count test kit happen most frequently when testing colostrum, late-lactation milk, or samples contaminated with debris. Fresh cows producing colostrum during the first three to five days postpartum naturally shed elevated epithelial cells and white blood cells without an active infection. Cows in extended late lactation also concentrate somatic cells as daily milk volume drops. To prevent inaccurate readings, avoid testing colostrum, clean teat ends thoroughly before sampling, and mix chemical reagents at room temperature.

Is buying an on-farm somatic cell count kit worth it for small herds?

Buying an on-farm somatic cell count kit is worth the investment for small herds because catching one subclinical mastitis case preserves bulk tank quality premiums. A small herd of 10 to 50 cows has less total volume, so a single infected cow can quickly spike the overall bulk tank cell count above 400,000 cells per milliliter. Losing milk quality bonuses or facing processor penalties often costs hundreds of dollars monthly. A simple 30-dollar paddle kit lets small producers identify problematic quarters immediately and avoid premature herd culling.