Cattle crisis has lessons for deer farmers

Cattle crisis has lessons for deer farmers

Friday, June 22, 2018

Mycoplasma bovis is unlikely to pose a risk to farmed deer in New Zealand, but the outbreak among cattle holds lessons about the importance of farm biosecurity for all involved in livestock farming.

Deer Industry NZ (DINZ) chair Ian Walker, who is also a veterinarian, says DINZ has been seeking expert and official advice on the threat to deer from Mp bovis since the disease was first detected in dairy cattle last year.

MPI and DINZ have found no evidence to date supporting the likelihood of Mp bovis being carried by New Zealand deer species. Mycoplasmas tend to be host-specific and Mp bovis, as its name suggests, is a pathogen that infects members of the bovine family including the North American bison,” he says.

In North America there have been two confirmed cases of Mp bovis having been isolated from white-tailed deer, a very low incidence rate in a national herd of about 30 million. White-tailed deer are only distantly related to the red, wapiti/elk and fallow deer farmed in New Zealand, but rather related to moose and reindeer.

Importantly, there have been no reports of isolation from elk in the United States, even though elk there often graze the same pastures as bison.

“DINZ, supported by MPI advice, therefore believes the risk of Mp bovis infecting farmed deer in New Zealand is extremely low. This is why MPI is tracing only cattle movements from infected properties to identify places at risk of being infected.”

Walker says the official advice on Mp bovis and deer is reassuring for deer farmers, but he advises them to treat it as a wake-up call for farm biosecurity.

“Tb, Johne’s disease, velvet leaf, Chilean needle grass and a number of other organisms are real and current threats that can be expensive to control. Stopping them before they come through the farm gate may be a bit of hassle, but good farm biosecurity will also make your farm more resilient to an exotic pest or disease,” he says.

“Let’s face it. We have all tended to see biosecurity as being largely the responsibility of people wearing uniforms at the border. But MPI Biosecurity can’t possibly stop everything, not with trade, travel and tourism increasing. There will be other incursions; you just don’t want the incursion to happen on your farm.”

Walker says it is also critical that if an exotic deer disease outbreak does occur, the industry is ready to quickly respond.

“That means being able to trace animal movements on and off the farm so that risk properties can be identified and the outbreak contained. That’s what NAIT is for.

“Ask yourself, how good are my NAIT records? If you do your best to comply with NAIT, at the very least you can’t be fined for non-compliance. But more positively, complying with NAIT means we are acting in our own interests, as well as the interests of the whole deer farming industry.”

MPI believes its tracing of at-risk beef and dairy properties for Mp bovis is robust. This means that if you farm or graze cattle you will have already been contacted if MPI believes they are at risk, Walker says.

“MPI believes the organism is contained by strict biosecurity controls on all infected and suspected properties, so the risk of your deer coming into contact with infected cattle is minimal,” he adds. 

“Therefore, while the eradication effort is underway, protect your farm and your deer by practising good basic farm biosecurity and, if you breed, raise or graze any cattle, follow MPI, B+LNZ and DairyNZ advice.”

Walker says DINZ will continue to monitor information about Mp bovis both in New Zealand and internationally. If there is any change in our assessment of extremely low Mp bovis risk to NZ farmed deer, farmers will be notified.

“If any deer farmer has any concerns about Mp bovis, please contact Catharine Sayer, Tony Pearse or Dan Coup at DINZ,” he says.