3 November 1995

More risks of mastitis

DAIRY farmers are urged to safeguard against an increased risk of environmental mastitis in housed freshly calved cows.

Our stock health update (see page 51) reports a seasonal rise in infections, especially the acute coliform type.

Dr Tony Andrews of the Royal Vet College attributes this trend to more cows calving this month, and more of those cows coming inside after calving. "If calving boxes are not cleaned properly between calvings then the infection will build up," he says.

Once the bug is in the herd, if the environment is mucky, or bedding warm and damp, it will grow and increase the chance of infection spreading to the cow, he says.

Cows will also be more vulnerable to such infections after calving and it takes one to two weeks for immunity to return to normal.

Furthermore, E coli bugs need iron to multiply, warns Dr Andrews. In the dry udder the iron is bound up in proteins so the bugs cant get hold of it. But this iron is released when the animal starts milking so there is plenty for the bugs to use. This risk, compounded by the cows reduced ability to combat infection, will predispose to environmental mastitis.

Dr Andrews advises bedding calving boxes and cubicles with plenty ofdry straw.

He also urges producers to ensure dung passageways are as clean as possible.

In some cases it may be necessary to scrape out more frequently.

Dr Andrews also stresses that loose dung contains more E coli bugs than firm pats. So silage should be supplemented with long fibre such as straw if necessary to bind it up. The process may also help digestion as well as improving dung quality.