Why Selective Dry Cow Therapy is Easier than Ever
The Dry Period is a critical point in the lactation cycle. A cow’s nutrition requirements and milk composition start changing in preparation for a new calf. It’s also the time that most mastitis infections are treated. In the past, you probably treated every single cow to make sure you didn’t miss an infection.
But it’s become much easier in recent years to be selective about which cows you treat.
Many livestock sectors are under growing pressure from consumers, government departments, and health agencies to reduce their antibiotic use. That includes dairy. Changes to treatment, especially during the dry period, have helped a lot. Udder health has been steadily rising over the past few decades. As a result, practices like Blanket Dry Cow Therapy (BDCT) are not as widely practiced as they once were.
Dry Cow Therapy of the Past
Dry Cow Therapy was introduced specifically to reduce subclinical mastitis. Farmers relied on visual udder inspection, palpation, and California Mastitis Tests (CMT) to diagnose infections. Even CMT tests had limited accuracy and relied on consistency between scorers.
In the 1960's, dairy experts introduced a set of guidelines called the 5 Point Mastitis Plan. Because it was impossible to directly detect infections, this plan encouraged BDCT. During the dry period, farmers treated each quarter to avoid missing an infection. This system was effective at controlling key pathogens such as Streptococcus agalactiae.
While BDCT achieved the goals of reducing major pathogens, the amount of antibiotics used to do this created some species of bacteria that are now resistant to treatment. As a result, researchers began studying Selective Dry Cow Therapy (SDCT) as an alternative option.
Early studies on the viability of SDCT initially had little success. This was due to inaccurate screening tests, clinical history records, and a lower use of teat sealants. These are all key factors determining the suitability of a herd for SDCT. The best technology at the time could only achieve at most about 70% accuracy.
But things have changed in the past 50 years.
Changing Problems Need Changing Tactics
The environment that cows live in is cleaner, and more attention is paid to milking hygiene. Combined with better quarantining, this means that fewer cases of mastitis are passed from cow to cow. As a result, the bacteria causing problems today are not the same ones that troubled dairy farmers in the past.
Today, there is a wider range of products available that are more effective at preventing and treating mastitis. These include antibiotics, teat dips, creams and ointments, supplements, and internal/external teat sealants.
Attitudes towards dry cow therapy have also changed. Many producers think the industry should be proactive in reducing antibiotic use. But, they also agree that responsible use shouldn't come at the expense of herd health. This has led to the saying, "As little as possible, but as much as necessary". SDCT is the direction many farms are going to achieve this.
The Future of Dry Cow Therapy is SDCT
Thanks to recent advances in screening technology, SDCT is now a much safer option. Testing devices are faster, more accurate and can be used anywhere in the barn. This enables treatment decisions to be based on real-time data. The ability to test individual quarters lowers the risk of missing an infection or treating a healthy quarter.
Many screening tools can indicate the probable pathogen causing the infection. This feature is key to the success of SDCT. The pathogen profile of a herd is one factor determining its suitability for SDCT. Knowing the causative pathogen also allows targeted treatment for that organism.
Herd management software is also a helpful feature of many screening devices. Producers can predict the number of at-risk cows during every dry period. Data reports can be generated for whole herds or for lists of cows of interest. Accurate clinical mastitis and SCC history for each cow can be checked whenever needed. All these tools help farmers make mastitis management decisions using real-time data. This is crucial for successful SDCT to select cows that should get treatment.
Both the shift in attitudes and advances in technology have helped us overcome the challenges of treating individual cows. When used with the proper selection criteria, SDCT can have outstanding results for herd health.
About the Author
Anna Schwanke is an undergraduate student at the University of Guelph, Ontario. She is responsible for researching and writing about a wide variety of topics related to dairy cow welfare and management for Dairy Quality Inc. The 10 years she spent living in Australia, as well as her love of travelling, give her a firsthand viewpoint of issues facing the international dairy community. She plans to graduate from the University’s College of Physical & Engineering Science in 2019 and pursue a career in the Life Sciences or Agriculture industry.
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