# Cost-Benefit Analysis of Dry Cow Therapy Protocols ## Key Takeaways - Blanket Dry Cow Therapy (BDCT), treating all cows with intramammary antibiotics, is indicated for herds with high somatic cell counts (SCC) or prevalent contagious mastitis pathogens like *Staphylococcus aureus* or *Streptococcus agalactiae*. - Selective Dry Cow Therapy (SDCT) targets only infected or high-SCC cows, potentially reducing antibiotic costs by 30-50%, but necessitates accurate recordkeeping and reliable testing strategies (e.g., SCC thresholds or milk cultures). - Internal teat sealants, non-antibiotic physical barriers, cost $3-$6 per cow and are effective in preventing new dry-period infections, often used alone in uninfected cows or adjunctively with antibiotics in infected ones. - The primary economic impact of mastitis is not the treatment cost but rather discarded milk, reduced subsequent lactation production (5-10% loss), increased culling risk (costing $1,500-$2,500 per replacement), and potential herd-wide pathogen spread. - Protocol effectiveness is best measured by cure rates (70-90% for common pathogens) and new infection rates (ideally <5% with treatment), with a cost-effective protocol prioritizing these outcomes over the per-unit price of the therapeutic agent. - Evaluating dry cow therapy economics requires calculating the cost of mastitis per case ($300-$500+), comparing protocol costs (product + labor), and quantifying the value of infections cured and new infections prevented, rather than solely focusing on antibiotic expenditure. --- Every dairy operation faces the same seasonal question: how much should you spend on dry cow treatment, and what will you get back for that investment? The answer depends on your herd's infection profile, your facilities, your labor situation, and the market for the milk you sell. This article walks through the economics of dry cow therapy so you can make a defensible decision for your own operation. It is written for dairy owners, herd managers, and the veterinarians and extension agents who advise them. Dry cow therapy is one of the largest single veterinary expenditures on many dairies, and it is also one of the most misunderstood. The old blanket approach of treating every cow at dry-off with a tube of long-acting antibiotic is giving way to more targeted strategies. Some of those strategies save money. Some cost more upfront but prevent larger losses later. The key is knowing which situation you are in before you commit to a protocol. ## At a Glance - **Blanket dry cow therapy (BDCT)** treats every cow at dry-off with an intramammary antibiotic. It remains the standard for herds with high [somatic cell](/blog/guides/somatic-cell) count (SCC) or a high prevalence of contagious mastitis pathogens. - **Selective dry cow therapy (SDCT)** treats only infected cows or cows with a history of high SCC. It can cut antibiotic costs by 30 to 50 percent but requires accurate recordkeeping and a reliable testing strategy. - **Internal teat sealants** are not antibiotics. They block the teat canal physically and are often used alone in uninfected cows or alongside antibiotics in infected cows. They cost roughly 3 to 6 dollars per cow but can prevent a large share of new dry-period infections. - **The biggest cost of mastitis is not the treatment tube.** It is the discarded milk, the lost production in the next lactation, the increased culling risk, and the potential for herd-wide spread of contagious pathogens. - **Your herd's cure rate and new infection rate matter more than the price of the product.** A cheap tube that cures fewer infections is usually more expensive in the long run than a premium product that works. - **Track your own data.** The only way to know whether a protocol change is working is to compare SCC, clinical mastitis cases, and culture results across dry periods before and after the change. - **Consult your veterinarian before changing protocols.** The decision involves antimicrobial stewardship, [food safety](/knowledge/bacteria/livestock-bacteria/cooking-chicken-bacteria-prevention), and animal welfare considerations that go beyond simple arithmetic. ## Understanding Dry Cow Therapy and Why It Exists The dry period is not a rest period for the udder. It is a time of intense physiological change, and it is also the period of highest risk for new intramammary infections. The udder is refitting itself for the next lactation. The teat canal undergoes changes in keratin composition and patency. The immune defenses that operate during lactation are partially suspended. And the cow is often housed in conditions with more bedding, more manure contact, and less frequent observation than the milking parlor provides. Dry cow therapy exists for two reasons. The first is to cure infections that are already present at dry-off. The second is to prevent new infections from establishing during the dry period. A long-acting antibiotic formulation persists in the udder for several weeks, providing a chemical barrier while the teat canal is most vulnerable. Teat sealants provide a physical barrier that lasts until calving. The economics of dry cow therapy are therefore the economics of two separate benefits. You are paying for a cure of existing infections and for prevention of new ones. Different protocols deliver these benefits in different proportions, and the value of each benefit depends on your herd's specific situation. ### The Cost of Mastitis in the Dry Period To understand whether dry cow therapy is worth the money, you first need to understand what mastitis costs when it is not treated. The losses are substantial and they compound across the lactation. **Discarded milk.** A cow that freshens with an infected quarter produces milk that must be discarded until she clears the infection or until antibiotic residues clear. At current milk prices, a single clinical case can cost 100 to 200 dollars in discarded milk alone. Subclinical infections do not cause visible flakes or clots, but they elevate SCC and may result in milk quality penalties from the processor. **Reduced production.** Cows that freshen with an infected quarter produce less milk for the entire lactation. The loss is not just at freshening. It persists for weeks or months. Research consistently shows that cows with elevated SCC at calving produce less milk across the whole lactation compared with their uninfected herdmates. The loss is typically 5 to 10 percent of total lactation yield for a subclinical infection, and more for clinical cases. **Increased culling.** Mastitis is one of the leading reasons for culling dairy cows. A cow that freshens with a chronic infection, especially in multiple quarters, is at high risk of being culled before the end of that lactation. Replacement heifers cost 1,500 to 2,500 dollars to raise or purchase. Every avoidable cull is a major financial hit. **Contagious spread.** Some mastitis pathogens are contagious. They spread from cow to cow, usually during milking. A cow that freshens with a contagious infection such as *Staphylococcus aureus* or *Streptococcus agalactiae* becomes a source of infection for the rest of the herd. One untreated cow can infect dozens over the course of a lactation. The cost of that spread is not captured in the individual cow's treatment bill. **Milk quality penalties.** Processors pay premiums for low SCC and impose penalties for high SCC. The threshold varies by processor and by market, but a herd that loses its quality premium can lose 0.25 to 1.00 dollar per hundredweight of milk shipped. For a 100-cow herd producing 2 million pounds of milk per year, that is 5,000 to 20,000 dollars in lost revenue. When you add these losses together, the cost of a single untreated dry-period infection often exceeds 300 to 500 dollars. That is far more than the cost of the antibiotic tube that could have prevented it. ## The Two Main Protocol Options: Blanket and Selective The most fundamental decision in dry cow therapy is whether to treat all cows or only some cows. Each approach has its own economics, and the right choice depends on herd-specific factors. ### Blanket Dry Cow Therapy Blanket dry cow therapy is the traditional approach. Every cow receives an intramammary antibiotic at dry-off, regardless of her infection status. The product is usually a long-acting formulation designed to persist in the udder for the entire dry period or a substantial portion of it. **Advantages of BDCT:** - **Simplicity.** There is no testing, no record review, and no decision-making at dry-off. Every cow gets the same treatment. - **Cures existing infections.** Cows that are infected at dry-off receive treatment that can clear the infection before calving. - **Prevents new infections.** The antibiotic provides a chemical barrier during the period when the teat canal is most vulnerable. - **No risk of missing an infected cow.** Even if your records are incomplete, every cow is covered. **Disadvantages of BDCT:** - **Antibiotic cost.** You pay for treatment of every cow, including the 60 to 80 percent that may not need it. - **Antimicrobial stewardship concerns.** Routine use of antibiotics in healthy animals is increasingly scrutinized by regulators, processors, and consumers. Some markets are moving toward restricting or discouraging blanket therapy. - **Residue risk.** The more cows you treat, the more opportunities for mistakes in withdrawal periods or accidental contamination of the bulk tank. - **Potential for resistance.** Overuse of antibiotics can select for resistant bacteria, although the evidence for this in dry cow therapy is less clear than in other settings. ### Selective Dry Cow Therapy Selective dry cow therapy treats only cows that are likely to be infected at dry-off. The selection is based on a combination of history, SCC records, and culture results. Uninfected cows receive either no treatment or a teat sealant alone. **Advantages of SDCT:** - **Lower antibiotic cost.** You only pay for treatment of the cows that need it. In a low-SCC herd, this can cut antibiotic expenditures by 50 percent or more. - **Reduced antimicrobial use.** This aligns with consumer expectations, regulatory trends, and good stewardship principles. - **Less labor at dry-off.** Fewer cows to treat means less time spent in the treatment chute. - **Lower residue risk.** Fewer treated cows means fewer opportunities for errors. **Disadvantages of SDCT:** - **Requires accurate data.** You need reliable SCC records, a history of clinical mastitis cases, and preferably culture results from high-risk cows. - **Requires a testing strategy.** Some protocols use SCC thresholds, some use culture of high-risk cows, and some use a combination. Each approach has costs and limitations. - **Risk of missing infections.** No selection method is perfect. Some infected cows will be missed and will freshen with untreated infections. - **More complex decision-making.** Someone has to make the call on each cow at dry-off, which requires training and consistency. ### The Economics of Choosing Between BDCT and SDCT The cost comparison between BDCT and SDCT is not simply a matter of counting tubes. You need to account for the value of the infections that SDCT misses and the cost of the testing that SDCT requires. Here is a simplified example. A 100-cow herd has an average bulk tank SCC of 200,000. Based on that SCC, roughly 25 percent of cows are likely infected at dry-off. The herd uses a product that costs 4 dollars per tube. **BDCT cost:** 100 cows times 4 dollars equals 400 dollars for antibiotics. **SDCT cost:** 25 cows times 4 dollars equals 100 dollars for antibiotics, plus testing costs. If the testing strategy is SCC-based, the records are already available and the incremental cost is near zero. If the testing strategy involves culturing composite samples from all cows, the cost might be 15 to 20 dollars per cow, or 1,500 to 2,000 dollars for the herd. In this example, SDCT with SCC-based selection is clearly cheaper. SDCT with culture-based selection may or may not be cheaper, depending on the culture cost and the accuracy of the test. But the comparison does not end there. SDCT will miss some infections. Suppose the selection method has 80 percent sensitivity, meaning it identifies 4 out of 5 infected cows. That means 5 infected cows are missed out of 25. Each missed infection costs 300 to 500 dollars in lost production, discarded milk, and culling risk. The cost of those missed infections is 1,500 to 2,500 dollars, which swamps the antibiotic savings. This is why the decision is not simple. The economics of SDCT depend heavily on: - The prevalence of infection in your herd - The accuracy of your selection method - The cost of the antibiotic - The cost of testing - The cost of a missed infection in your specific operation In a low-SCC herd with excellent records and a high-quality selection method, SDCT can save significant money. In a high-SCC herd with poor records, SDCT can be a false economy. ## Teat Sealants: The Third Piece of the Puzzle Internal teat sealants are non-antibiotic products that physically block the teat canal. They are injected into the teat at dry-off and form a plug that prevents bacteria from entering. The plug is expressed naturally at calving or removed by the milker. Teat sealants are not a replacement for antibiotics in infected cows. They have no curative effect. But they are highly effective at preventing new infections, particularly from environmental pathogens such as *E. coli* and environmental streptococci. The economics of teat sealants depend on whether they replace or supplement antibiotics. **Sealant alone in uninfected cows.** In a cow that is confirmed uninfected at dry-off, a sealant alone can provide excellent protection against new infections. The cost is 3 to 6 dollars per cow, which is comparable to or less than the cost of an antibiotic tube. This is the strategy used in many SDCT protocols. **Sealant plus antibiotic in infected cows.** In an infected cow, a sealant adds protection after the antibiotic has done its curative work. The antibiotic clears the infection in the first few weeks of the dry period, and the sealant prevents new infections for the rest of the dry period. This combination is more expensive but may be cost-effective in herds with high rates of environmental mastitis. **Sealant plus antibiotic in all cows.** Some herds use a sealant plus an antibiotic in every cow. This is the most expensive option, but it provides the highest level of protection. It may be justified in herds with very high environmental challenge, such as those in wet climates or with poor bedding management. The key economic question for teat sealants is whether the prevention of new infections is worth the cost. If your herd has a low rate of new dry-period infections, sealants may not pay for themselves. If your herd has a high rate, they can be one of the most cost-effective mastitis control investments you make. ## Step-by-Step: How to Evaluate Your Own Dry Cow Therapy Economics You cannot make a sound decision about dry cow therapy without knowing your own numbers. Here is a step-by-step process for gathering the data you need and running the calculations. ### Step 1: Determine Your Herd's Infection Prevalence The first number you need is the proportion of cows that are infected at dry-off. The best source of this data is a series of milk cultures from cows at dry-off. If you do not have culture data, you can estimate prevalence from SCC records. A common rule of thumb is that cows with a composite SCC above 200,000 cells per milliliter at the last test before dry-off are likely infected. Cows with SCC above 100,000 in an individual quarter are also likely infected. The higher the SCC, the more likely the cow is infected. If your herd's bulk tank SCC is below 150,000, your infection prevalence is probably below 20 percent. If bulk tank SCC is above 250,000, prevalence is probably above 30 percent. These are rough estimates, not precise measurements, but they are a starting point. ### Step 2: Calculate Your Current Antibiotic Cost The next number is the cost of your current protocol. This includes the product cost and the labor cost of administration. **Product cost:** Multiply the number of cows dried off per year by the cost per tube. If you treat every cow in all four quarters, multiply the number of cows by 4 and then by the cost per tube. Remember that some products are sold in syringes that contain multiple tubes or in bulk packs. **Labor cost:** Estimate the time it takes to treat a cow. A skilled worker can treat a cow in 3 to 5 minutes, including restraint, preparation, and infusion. Multiply the time per cow by your labor rate. If the milker or herdsperson earns 20 dollars per hour, the labor cost is about 1 to 2 dollars per cow. **Total cost:** Add the product and labor costs to get the total cost of your current protocol. ### Step 3: Estimate the Cost of Mastitis in Your Herd This is the harder number to calculate, but it is essential. You need to estimate what mastitis costs you per case, including: - Discarded milk from clinical cases at freshening - Reduced production in the next lactation - Increased culling risk - Milk quality penalties - Treatment costs for clinical cases after freshening A reasonable estimate for a clinical case is 200 to 400 dollars. A subclinical case is 100 to 200 dollars. These numbers vary by region, milk price, and herd productivity, so adjust them to your situation. ### Step 4: Estimate the Effectiveness of Your Current Protocol The effectiveness of a dry cow therapy protocol is measured by two outcomes: the cure rate and the new infection rate. **Cure rate** is the proportion of infected quarters that are cured by the treatment. Most effective dry cow antibiotic products cure 70 to 90 percent of infections caused by common pathogens. The cure rate is lower for chronic infections, old cows, and infections with certain pathogens such as *Staph. aureus*. **New infection rate** is the proportion of uninfected quarters that become infected during the dry period. With no treatment, the new infection rate might be 10 to 20 percent. With an effective antibiotic and sealant, it can be reduced to 2 to 5 percent. You can estimate these rates from your own records by comparing SCC or culture results before dry-off and after calving. If you do not have this data, ask your veterinarian or extension agent to help you set up a monitoring program. ### Step 5: Compare the Costs and Benefits Now you can build a simple comparison. For each protocol option, calculate: - The cost of the protocol (product plus labor) - The expected number of infections cured - The expected number of new infections prevented - The value of those cured and prevented infections - The net cost or benefit Here is a worked example for a 100-cow herd with 25 percent infection prevalence: **Option A: BDCT with antibiotic alone** - Antibiotic cost: 100 cows times 4 tubes per cow times 4 dollars per tube = 1,600 dollars - Labor cost: 100 cows times 1.50 dollars = 150 dollars - Total cost: 1,750 dollars - Expected cures: 25 infected cows times 80 percent cure rate = 20 cures - Expected new infections prevented: 75 uninfected cows times 10 percent baseline new infection rate times 50 percent reduction = 3.75 prevented - Value of cures and prevention: 23.75 cases times 300 dollars per case = 7,125 dollars - Net benefit: 7,125 minus 1,750 = 5,375 dollars **Option B: SDCT with SCC-based selection** - Antibiotic cost: 25 infected cows times 4 tubes per cow times 4 dollars per tube = 400 dollars - Labor cost: 25 cows times 1.50 dollars = 37.50 dollars - Testing cost: 0 dollars (using existing SCC records) - Total cost: 437.50 dollars - Expected cures: 25 infected cows times 90 percent selection sensitivity times 80 percent cure rate = 18 cures - Missed infections: 25 infected cows times 10 percent missed = 2.5 missed infections - Expected new infections prevented: 75 uninfected cows times 10 percent baseline new infection rate times 30 percent reduction = 2.25 prevented - Total cases avoided: 18 plus 2.25 = 20.25 - Value: 20.25 times 300 dollars = 6,075 dollars - Cost of missed infections: 2.5 times 300 dollars = 750 dollars - Net benefit: 6,075 minus 437.50 minus 750 = 4,887.50 dollars In this example, BDCT has a slightly higher net benefit than SDCT, even though SDCT costs less upfront. The difference is driven by the missed infections in the SDCT protocol. But the numbers change if you add a sealant to the SDCT protocol for uninfected cows: **Option C: SDCT with sealant for uninfected cows** - Antibiotic cost for infected cows: 25 cows times 4 tubes per cow times 4 dollars per tube = 400 dollars - Sealant cost for uninfected cows: 75 cows times 4 tubes per cow times 4.50 dollars per tube = 1,350 dollars - Labor cost: 100 cows times 1.50 dollars = 150 dollars - Testing cost: 0 dollars - Total cost: 1,900 dollars - Expected cures: 18 cures (same as Option B) - Missed infections: 2.5 missed infections - Expected new infections prevented: 75 uninfected cows times 10 percent baseline new infection rate times 80 percent reduction = 6 prevented - Total cases avoided: 18 plus 6 = 24 - Value: 24 times 300 dollars = 7,200 dollars - Cost of missed infections: 2.5 times 300 dollars = 750 dollars - Net benefit: 7,200 minus 1,900 minus 750 = 4,550 dollars In this example, Option C has a lower net benefit than Option A because the sealant cost is high and the baseline new infection rate is moderate. But if the baseline new infection rate were higher, say 20 percent, the sealant would look much better. The point of these examples is not to tell you which protocol to choose. It is to show you how to run the numbers for your own herd. The results depend entirely on your specific situation. ## Common Mistakes in Dry Cow Therapy Economics Farmers and even some advisers make predictable errors when evaluating dry cow therapy costs. Here are the most common ones and how to avoid them. ### Mistake 1: Counting Only the Product Cost The price of the antibiotic tube is the most visible cost, but it is not the only cost. Labor, testing, and the cost of missed infections are all part of the equation. A protocol that looks expensive per tube may be cheaper overall if it prevents more infections. ### Mistake 2: Ignoring the Cost of Missed Infections SDCT saves money on antibiotics, but it inevitably misses some infections. If you do not account for the cost of those missed infections, you will overestimate the savings from SDCT. The lower your herd's infection prevalence and the better your selection method, the smaller this problem becomes. ### Mistake 3: Assuming Your Records Are Accurate SDCT depends on accurate records. If your SCC records are unreliable, if you do not record clinical mastitis cases, or if your herd identification system has gaps, you will make bad decisions about which cows to treat. Fix your records before you switch to SDCT. ### Mistake 4: Changing Protocols Without a Baseline If you switch from BDCT to SDCT without first measuring your current cure rates and new infection rates, you will not know whether the change helped or hurt. Establish a baseline before you change anything. ### Mistake 5: Treating All Cows the Same Cows are not interchangeable. First-lactation heifers have lower infection rates and better cure rates than old cows. Cows with a history of clinical mastitis are higher risk than cows with clean records. A one-size-fits-all protocol ignores these differences and leaves money on the table. ### Mistake 6: Overlooking the Value of Prevention Antibiotics are curative, but they also prevent new infections during the dry period. When you compare protocols, remember that the prevention benefit is often worth more than the cure benefit, especially in herds with high environmental challenge. ### Mistake 7: Making Decisions on One Year of Data Mastitis patterns vary from year to year with weather, bedding, and other factors. A single dry period is not enough data to judge a protocol. Track your results over at least two or three years before drawing conclusions. ## Decision Thresholds: When to Choose Which Protocol While every herd is different, some general thresholds can guide your decision. ### Choose BDCT When: - Your bulk tank SCC is consistently above 250,000 - Your infection prevalence at dry-off is above 30 percent - Your records are incomplete or unreliable - You have a high prevalence of contagious pathogens such as *Staph. aureus* or *Strep. agalactiae* - Your herd has a high rate of clinical mastitis at freshening - You lack the labor or training to implement a selective program properly ### Choose SDCT When: - Your bulk tank SCC is consistently below 150,000 - Your infection prevalence at dry-off is below 20 percent - Your records are accurate and complete - You have a reliable method for identifying infected cows - Your herd has a low prevalence of contagious pathogens - You are under pressure to reduce antimicrobial use ### Consider Adding Teat Sealants When: - Your herd has a high rate of environmental mastitis - Your dry cow housing is clean and dry but new infections still occur - Your dry period is longer than 60 days - You are using SDCT and want to protect uninfected cows - Your veterinarian recommends them based on culture results These thresholds are starting points, not hard rules. Your veterinarian can help you refine them based on your specific situation. ## Monitoring and Recordkeeping Whatever protocol you choose, you need a system for tracking results. Without data, you are guessing. ### What to Track At minimum, track these metrics for every dry period: - **SCC at last test before dry-off.** This tells you which cows are likely infected. - **SCC at first test after calving.** This tells you whether the infection was cured. - **Clinical mastitis cases in the first 30 days after calving.** This is a key indicator of dry-period problems. - **Culture results from clinical cases.** This tells you which pathogens are causing problems. - **Culling due to mastitis.** This is the most expensive outcome of a failed dry period. - **Milk quality penalties or premiums.** This tells you how the herd's overall udder health is trending. ### How to Use the Data Compare your metrics across dry periods. If you switch protocols, compare the results before and after the change. Look for trends over time, not just single events. A simple spreadsheet is sufficient for many herds. Record the cow ID, dry-off date, calving date, SCC before and after, and any clinical cases. Review the data with your veterinarian at least twice a year. ### The Role of [Culture and Sensitivity Testing](/knowledge/veterinary-medicine/at-home-diagnostics/culture-and-sensitivity-testing-managing-multi-drug-resistant-pet-infections) Culture and sensitivity testing has two roles in dry cow therapy economics. First, it can identify which cows are infected at dry-off, which is essential for SDCT. Composite samples from high-risk cows can be cultured at a diagnostic laboratory for 15 to 25 dollars per sample. On-farm culture kits are cheaper but less accurate. Second, it can identify which pathogens are present in your herd and which antibiotics are likely to be effective. If you are treating infections that are resistant to your chosen product, you are wasting money. Periodic herd-level culture surveys can prevent this. ### Working With Your Veterinarian Your veterinarian is an essential partner in dry cow therapy decisions. They can: - Help you interpret SCC data and culture results - Recommend products based on your herd's pathogen profile - Help you set up a monitoring program - Advise on antimicrobial stewardship and regulatory requirements - Help you calculate the economics for your specific situation - Provide the prescription for any products that require one Do not make major protocol changes without veterinary input. The decision involves animal health, food safety, and regulatory considerations that go beyond simple arithmetic. ## When to Call a Veterinarian or Extension Agent Some situations call for professional help beyond routine monitoring. **Call your veterinarian when:** - Your bulk tank SCC is rising despite your current protocol - You see an outbreak of clinical mastitis at freshening - You are considering a switch between BDCT and SDCT - You are considering adding or removing teat sealants - You have not reviewed your dry cow protocol in more than a year - You are unsure which cows are infected at dry-off - You are experiencing a high rate of antibiotic failures **Call your extension agent when:** - You want help setting up a recordkeeping system - You need assistance interpreting your herd's SCC data - You want to compare your protocol with regional or national benchmarks - You are planning a herd health meeting and want an outside perspective - You are considering facility changes that affect dry cow housing ## Frequently Asked Questions ### How much does dry cow therapy cost per cow? The cost of dry cow therapy varies widely by product, protocol, and region. A single tube of intramammary antibiotic typically costs 3 to 8 dollars. Treating all four quarters of a cow costs 12 to 32 dollars in product alone. Internal teat sealants cost 3 to 6 dollars per tube, or 12 to 24 dollars for all four quarters. Labor adds 1 to 2 dollars per cow. A full BDCT protocol with sealant can cost 25 to 50 dollars per cow. An SDCT protocol that treats only infected cows can cost much less, but requires testing and accurate records. ### Is selective dry cow therapy cheaper than blanket therapy? Selective dry cow therapy usually has a lower upfront cost because you buy fewer antibiotic tubes. However, the total cost depends on the testing strategy, the accuracy of the selection, and the cost of missed infections. In a low-SCC herd with good records, SDCT is typically cheaper overall. In a high-SCC herd with poor records, SDCT can be more expensive because missed infections cause losses that exceed the antibiotic savings. ### Can I use teat sealants without antibiotics? Yes. Teat sealants are often used alone in cows that are confirmed uninfected at dry-off. This is a common component of SDCT protocols. The sealant prevents new infections during the dry period without using antibiotics. However, a sealant will not cure an existing infection. If you use sealants alone, you must be confident that the cow is not infected at dry-off. ### How do I know if my dry cow therapy is working? Track your herd's SCC, clinical mastitis cases, and culture results across dry periods. Compare the SCC at the last test before dry-off with the SCC at the first test after calving. A successful protocol should result in most cows freshening with lower SCC than they had at dry-off. You should also see few clinical cases in the first 30 days after calving. Review this data with your veterinarian at least twice a year. ### What is the best dry cow therapy for a high-SCC herd? For a herd with high SCC and a high prevalence of infection, blanket dry cow therapy with an effective antibiotic is usually the best choice. Adding an internal teat sealant can provide additional protection against new infections. Your veterinarian should help you choose a product based on the pathogens present in your herd and the results of culture and sensitivity testing. ### How long should the dry period be for dry cow therapy to work? Most dry cow antibiotic products are designed to persist in the udder for 4 to 8 weeks. A dry period of 45 to 60 days is typical and allows the product to provide protection for most of the dry period. Very short dry periods of less than 30 days may not allow the product to work fully. Very long dry periods of more than 70 days may leave the cow unprotected at the end of the dry period. If your dry period is longer than 60 days, discuss the timing of treatment with your veterinarian. ### Will using fewer antibiotics hurt my milk quality? Not necessarily. The goal of SDCT is to use antibiotics only where they are needed. If your selection method is accurate, you will not miss many infections, and your milk quality should be maintained or improved. However, if your selection method is poor or your records are incomplete, you may miss infections and see your SCC rise. The key is to monitor your results closely after any protocol change. ### Do I need to culture milk samples before switching to selective dry cow therapy? Culturing milk samples is the most accurate way to identify infected cows at dry-off. However, it is not always necessary. Some SDCT protocols use SCC records alone to select cows for treatment. The accuracy of SCC-based selection depends on the quality and recency of your SCC data. If your records are good and your herd has a low prevalence of infection, SCC-based selection may be sufficient. If your records are poor or your infection prevalence is high, culturing is worth the cost. ## Related Farming Guides This section will be populated with links to related farming guides on dry cow management, mastitis control, milk quality, and dairy herd health. Check back for updates or explore the rest of the site for more practical dairy farming resources. ## Related Clinical & Scientific Guides * [Evaluating Feed Additives for Dairy Cow Performance](/knowledge/animal-farming/dairy-cattle/evaluating-feed-additives-for-dairy-cow-performance) * [Dairy Barn Fire Safety: Design and Prevention Measures](/knowledge/animal-farming/dairy-cattle/dairy-barn-fire-safety-design-prevention) * [Dairy Cow Pregnancy Loss Records and Review](/knowledge/animal-farming/dairy-cattle/dairy-cow-pregnancy-loss-records-and-review) ## References - National Mastitis Council: https://www.nmconline.org/ - USDA APHIS Dairy Cattle Health: https://www.aphis.usda.gov/livestock-poultry-disease/cattle - FAO Dairy Production and Products: https://www.fao.org/dairy-production-products/en/ - FAO Animal Production and Health: https://www.fao.org/animal-production/en/ - WOAH (World Organisation for Animal Health): https://www.woah.org/en/home/ > This article is educational and is not a substitute for veterinary diagnosis, treatment, public-health guidance, or regulatory reporting.