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Virginia Cooperative Extension - Knowledge for the CommonWealth

Tips on minimizing new mastitis infections during the dry period

Dairy Pipeline: May 2001

Gerald M. (Jerry) Jones
Professor and Extension Dairy Scientist
Milk Quality & Milking Management

Cows, including heifers, are prone to development of new udder infections during the dry period. In fact, they are most prone in the several weeks before and after calving as well as the first couple weeks after being dried off. Mastitis infections at calving are associated with high somatic cell counts and an increased risk of clinical mastitis. Several presentations at the 2001 National Mastitis Council meeting discussed mastitis that occurs during this time. Let's review a few management tips that help to minimize these infections. Usually the best way to dry off a cow is to stop milking her and dry treat her immediately after the last milking, following the drug label's recommendations. But first, scrub the teat end with alcohol. Only insert the cannula into the teat canal (called partial insertion) avoiding any contamination of the cannula. Follow treatment with teat dipping, covering most of the teat. In cases of cows that are high producers at time of drying off, you can reduce milk yield by intermittent milking for a week, feeding only hay, and then stop milking them. A 60 day dry period is desired. Turn them out into a clean and dry environment because it takes a few days for the keratin plug to form in the teat end. This would be the time to begin an E. coli vaccination program, using label recommendations as to when and how much. Research has shown that at 2-3 weeks before expected calving, cows and heifers could benefit from adding vitamin E and selenium (Se) to the ration as well as an injection containing E and Se. Injections should be administered in the neck if possible (to avoid carcass blemishes). Dry cow management is a critical time for preventing new mastitis infections.

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