Cows at high risk of mastitis around drying off

Environmental mastitis sometimes occurs in cows after they are dried off. Cows are at greatest risk of becoming infected by environmental mastitis at this time because their teat ends take a number of days after drying off to fully close.

Research has found that some cows teat ends never seal properly – particularly at risk are higher yielding and ‘free’ milking cows.

The jury is out about what to do in the case of cows that ‘run’ milk after drying off. Some experts believe that you should milk out the quarter and reapply a dry cow tube and teat sealant. Others believe in the ‘hands off’ approach. At this stage, I’m tending towards the ‘hands off’ approach and only intervening where there are signs of an infection. The risk of introducing an infection when applying a teat sealant or dry cow tube to a cow that is running milk is in my mind too great. Better to manage their diet during the early dry period to ensure that they ‘soak up’ properly and house them as hygienically as possible to minimise the risk of early dry period infection.

Immediate tasks

• Clean dry cubicle beds are a must – clean the ends of cubicle beds twice a day from two weeks before the start of calving. Sprinkle cubicle lime at the ends of the beds daily to reduce bacterial contamination and dry the bed. Remove damp bedding material such as chopped straw or sawdust daily. 
• Cubicle passages should be cleaned at least twice daily in the two weeks after dry off to reduce the build up of dung in the passageways.

Longer term tasks

• If condensation is a problem, improve house ventilation. Sure signs of ventilation problems are discolouration of the roof purlins and water dropping onto cubicle beds.
• Record cases of dry period mastitis (indeed of all mastitis cases) on the ICBF website. Doing so will allow you to build up a picture of the pattern of mastitis infection in your herd. Should a problem arise, good records will help you to determine the cause of the problem and the affected animals on your farm.

In summary, cows in the early dry period are especially vulnerable to mastitis. The bacteria that cause such infections are widespread in the cow’s environment so early dry period nutrition and maintaining dry cubicle beds and clean passageways will help to reduce the risk of infection.

The Teagasc Dairy Specialists issue an article on a topic of interest to dairy farmers every Monday here on Teagasc Daily.