A farm in the Ashburton district has been identified as having M. bovis via routine testing, bringing the total number of infected farms in the region to three.
The Ministry of Primary Industries (MPI) eradication programme was carrying out cattle movement tracing and genomic analysis as was standard practice when a property was confirmed infected, and was working closely with the farmer.
Investigations on this property were “in the early stages,” MPI said, and genomic analyses, as well as cattle movement tracing, was under way to help understand the infection source.
Nick Giera, Federated Farmers dairy representative for Mid Canterbury said the disease was still at a very low level and there might well be an underlying level of infection that existed for a number of years.
“It might spike up every now and again depending on the weather. For instance, at the moment, the cows are under stress with calving and coming out of winter. It’s likely that if there is any underlying infection it will pop up now.
“I don’t think this is the start of a trend,” Giera said.
“I can see this scenario going on for a few years – I think the disease will have a long tail before we eradicate it completely. I think MPI probably understands this and it’s part of the plan for eradication.”
MPI said it wouldn’t be surprising to find more infected farms at this stage in the eradication effort.
“In fact, we can expect to find more as we continue on this journey,” it said.
Farmers could take heart that, while MPI might find further infection, it was undertaking a significant amount of surveillance, which showed the disease was not widespread.
“The number of infected farms has tailed off over the past 18 months.
With high levels of background and network surveillance being undertaken and very few new active confirmed properties we can be optimistic that good progress has been made towards eradication, and that we are at the ‘tail end’ of the disease outbreak.”
MPI urged farmers to carry out general biosecurity measures at calving to help protect against diseases.
As the weather warmed up, older calves were ready to go outside the shed and the twice-daily milking schedule was cut down to once a day.
This was a stressful time when M. bovis bacteria might be shed.
It was also a time when calves often got mixed with other cattle, perhaps being sold on or new calves coming onto the farm.
This meant a high-risk of infection.

• By Pat Deavoll