Dairy farmers are being warned greater use of European and North American methods risks an increase in coliform mastitis, which inflames cows' udders and hits milk production.
Coliform mastitis causes 50-70 per cent of mastitis in the Northern Hemisphere but only 2 per cent here.
Dexcel mastitis specialist Jane Lacy-Hulbert
said she did not believe coliform mastitis would become a big problem here because dairy farming and feeding was mostly in the open.
A greater shift towards practices such as housing cows indoors, feeding them on concrete or bark pads, and using supplementary feeds would raise the risk of developing mastitis.
Lacy-Hulbert was involved in a trial where cows were fed either on pasture grass or a mixture of food with no grazing. Coliform mastitis took off in the latter group. A high-carb supplement diet raised E. coli levels and the risk of developing mastitis.
David McDonnell, dairy business manager of animal health company Intervet, said E. coli could build up on feed pads even if they were washed down regularly.
