M. bovis eradication still on the cards

Welcoming the early results, Agriculture and Biosecurity Minister Damien O’Connor said it showed that eradication remains a viable option.

“This is a good result and gives us confidence we are on the right track as we hunt down this disease,” he said.

“However, there is still a big job to do to determine the extent of the spread; we have two rounds of discarded milk testing to complete. The discarded milk comes from animals displaying an illness of some type and may paint a different picture.”

The surveillance involves testing milk from all New Zealand’s 12,000 dairy farms, in three rounds: first a sample of bulk milk from the tanker, followed by two samples -- two weeks apart -- of each farm’s discarded or mastitic milk.  

O’Connor was speaking after 9100 of the bulk samples had been tested but before any results were available from the discard samples.

He said MPI is working with urgency to get a full picture of the scale and location of the disease so as to see clearly whether nationwide eradication is feasible and economically viable.

“MPI’s own tracing programme is a critical part of this. To date a vast web of some 1500 farms has been connected from animal movements, and more than 85,000 samples from at-risk herds have been tested. Clearly most of these farms have been ruled out from having the disease but the task is intensive and MPI has accelerated this work through additional laboratory and field capacity.”

O’Connor said the tracing programme was made more difficult by, it seems, many unrecorded calf movements around the Southland infection cluster. 

MPI will soon start publicly encouraging farmers to report any at risk-animal movements that are not captured in recording systems such as NAIT.

MPI response coordinator David Yard stressed that ‘not detected’ meant only that the disease had not been found in the 9100 samples. 

“There is a possibility that we have ‘silent shedders’ -- cows that aren’t shedding.” (He was speaking to Dairy News from Northland where he was attending meetings where the milk sampling packs were distributed to farmers.) 

Yard could not give figures on farmers’ compliance with the testing but he believes their take-up has been good.

“Once we’ve explained what the benefits are to the industry and that we’re doing this for them, I think we’ve swung a lot of people over.”

60% of farmers invited to their district meetings had attended; absentees were followed up by their dairy companies.