A Fresh Reason to Monitor Somatic Cell Count
Somatic Cell Count (SCC) is a measure of the intensity of the work being done by a cow’s immune system. There are many causes for an elevated SCC, including the lactation stage.
Fresh cows are at a higher risk of infection from mastitis causing pathogens.
Recent studies by the Rutgers Cooperative estimate that 50% of heifers freshen with an intramammary infection and up to 90% have at least one infected quarter when they calve. Routinely monitoring the SCC levels of fresh cows is an effective way to maintain bulk tank SCC and to catch infections early on, improving treatment options and efficiency to minimize cost.
Cows are most susceptible to mastitis at calving time due to milk leakage which provides easy access for bacteria to penetrate the teat canal, the decreased flushing of bacteria during milking, and the lack of teat disinfection.
This is demonstrated by the fact that environmental pathogens such as Streptococcus spp., E. coli and Klebsiella spp. are most commonly cultured from fresh cows. Since a cow’s immune system is naturally suppressed at calving time an SCC elevation is normal for the first 1-2 weeks postpartum. After this period an uninfected heifer should have an SCC below 75,000. Cows that freshen over 200,000 are more likely to experience clinical mastitis in early lactation.
Studies by the University of Wisconsin- Madison show that the most sensitive time period for infection was 3-5 days post calving. Cows that are sick during their fresh period often do not reach full lactation potential. Feed requirements may stay the same, although the yield is reduced, decreasing revenue.
There are several benefits to routinely screening fresh cows:
- Due to the natural SCC elevation arising from immune system suppression, milk from fresh cows may increase bulk tank SCC and should always be tested. This helps keep the bulk tank low.
- Fresh cow screening helps keep SCC levels low throughout the rest of the lactation by allowing infections to be detected and treated earlier. The sooner an infection is detected, the less the disease has an opportunity to progress and the more treatment options remain available.
- Screening lowers bacterial counts and results in fewer cases of clinical mastitis throughout the rest of the lactation period.
- In addition to preventing and reducing the severity of mastitis, screening also allows for evaluation and adjustment of your dry cow treatment program.
Whether you are a small family run herd or a commercial producer, fresh cows represent a significant source of revenue as they prepare to enter the lactating herd. Today’s availability of handheld SCC testing devices are an invaluable tool to ensure these cows get off to the right start.
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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