Warning at bovis meeting about intensive farming

MPI says intensive farming of housed livestock could pose difficulties for animal health. Photo / File

Intensive farming of housed livestock could pose difficulties for animal health, Ministry for Primary Industries technical liaison officer Victoria Barrell says.

At a public meeting on Thursday to discuss the Mycoplasma bovis outbreak, she said New Zealand was moving towards a dual farming system, where livestock was kept indoors for part of the year.

That required a new level of management and skill set to ensure good production and animal health, Dr Barrell said.

When M. bovis was first seen on two Van Leeuwen Dairy Group farms, it presented very differently on each property. At the one where cattle were farmed intensively and indoors for a time, "the clinical signs were horrendous''.

On the other farm, where cattle were grazing outside, there were "no clinical signs''.

"A lot of scientific literature overseas shows the more intensive, robotic-type production, the more clinical signs there are.''

Although robotic milking systems washed the cows, they were not cleaning them well enough, Dr Barrell said.

"We're looking at welfare regulations around this new generation of dairy farms.''

She said she was not saying there was anything wrong with the Van Leeuwen Dairy Group's robotic farms. However, there "seems to be a link'' between intense, highly mechanised farming and M. bovis.

But once it was endemic, it did not matter what farming system was used, she said.

New Zealanders might never know how Mycoplasma bovis got into the country, ministry director of response Geoff Gwyn said. Ministry staff were investigating the possible pathways and a report was due by the end of next month.

Six pathways were being analysed comprehensively. Even if there was strong evidence supporting one of those pathways, it might not be enough to be certain, he said.

Dr Barrell said laboratory staff were carrying out gene sequencing to see which strain of M. bovis was here, which would indicate where it might have come from.

"That will help lead us down the entry pathway.''