Phased eradication of M. bovis: a regretful necessity

The government met with New Zealand’s agriculture leaders two weeks ago to discuss solutions to the Mycoplasma Bovis crisis, which has spiraled out of control in recent months.

They decided the most efficient, cost-effective strategy was phased eradication, a process that will involve the culling of 126,000 cows, on top of the 26,000 already killed, and will cost an estimated $886 million over the next decade.

So what exactly is ‘phased eradication’, and why is it necessary?

A spokesperson from the Ministry of Primary Industries explains in simple terms:

“Phased eradication means we’re attempting to completely get rid of Mycoplasma bovis from New Zealand’s dairy and beef herds. It will mean continuing to trace all potentially affected cows, test and cull those herds with infected animals in them. It will continue until regular surveillance finds no further evidence of the disease. By phased, we mean that it will take place over a number of years and in cooperation with farmers to allow for some flexibility around timing of culling to offset production losses.”

There is no doubt the move will cause distress and anguish for many. The heart-breaking reaction of Canterbury farmer Frank Peters to the culling of his 670-strong herd likely still lingers in the thoughts of many and is a reminder that behind this issue are real people, with families to feed and lifestyles to uphold.

However, as Waikato Federated Farmers President Andrew McGiven says, eradication is a tough but necessary sacrifice the country must make:

“Only one strain of M bovis has been detected here but it appears to be much more virulent than other strains of the disease. There have been several case studies where it has decimated entire herds in Britain and Europe… This is our one shot at ridding ourselves of this nasty burden on our livestock industry. I know it seems like we are being cruel to be kind, but this is an insidious disease that affects the very welfare of our precious animals. I say if we have a chance to eject it from the country then we should take it.”

When it comes to issues of animal health, none are more qualified than veterinarians and their view of the government’s decision suggests it is the right move forward.

Dr Helen Beattie of the NZ Veterinary Association confirmed this in a discussion with the SMC last week, where she talked about the difficulty of disease management overseas and asserted eradication was the “best solution” for New Zealand:

“As a veterinarian working on the foot and mouth response in the UK, I’ve seen the misery that outbreaks of serious infectious diseases can bring down on the agricultural sector – animals, farmers and their communities. Containing these outbreaks always involves hard choices and significant consequences – there are seldom any easy solutions.

"From a veterinarian’s point of view, eradicating this disease is the best solution. It is by far the best outcome from an animal welfare point of view. Long-term, it would also be best for farmer wellbeing and for minimising antimicrobial use on farms, which has implications for preventing antibiotic resistance.”

Alongside the effects decontamination and intensive movement control would have on productivity, a number of other factors would contribute to significant economic losses should we vote against eradication, such as herd longevity.

New Zealand’s cows have relatively long lives compared to those overseas. On average, cows are about seven years old when they go to the meat works here. In America, they are only around five. Shorter longevity means more replacement cows, which results in elevated greenhouse gas emissions per unit of milk.

Farmers are already spending upward of a billion dollars a year to combat the pollutive side-effects of their activities, the last thing they need is for these effects to worsen.

Another point to consider is the pasteurization of raw milk.

In New Zealand, waste milk is fed to calves without pasteurization. Overseas, because of the presence of M bovis, general practise has become heating the milk to around 63 degrees Celsius, a process which, if adopted over here, will mean extra costs for the technology and gear needed to do so.

Cost factors like these played a key role in the decision-making process that ultimately led to eradication. ASB Bank chief economist Nick Tuffley estimated the price of disease management to be around 1.3 billion dollars, roughly four hundred million more than the projected cost of eradication.

Additionally, unlike other countries which deal with multiple strains of the disease, M bovis in New Zealand is believed to have come from a single point of entry and is a singular strain. This, according to Chris Lewis of Federated Farmers, gives us a far better chance of getting rid of it:

“In New Zealand they are saying it’s a single strain, coming in from one source. While the numbers make it sound like it’s gone to a lot of farms, when you put it in context, it hasn’t really, and the experts think we have a good shot at eradicating it.”

Lewis noted that farmers overseas are now beginning to focus their attention on New Zealand’s eradication effort, which should it succeed, would, he says, spurn other nations to attempt the same:

“What I’m also noticing is that some overseas countries are starting to take notice of what we’re doing, and some farmers overseas are saying – “well if New Zealand can do it, why can’t we do it?”

"So if we are successful with eradication, it may be a bench mark for other countries in the future, certainly all eyes are on us at the moment. “

Some have worried that culling on this scale will effect beef and milk prices, however the Ministry for Primary Industries says it’s a non-issue:

“We do not expect phased eradication of cattle with Mycoplasma bovis to have an impact on beef or milk prices. It is important to note phased eradication will take place over several years. The number of animals being culled is insignificant compared to the total number of animals that are culled in New Zealand every year.

New Zealand has been battling with the management of another major cattle disease, bovine TB, for more than fifty years. This struggle provides a good blueprint for how serious an effect mycoplasma could have on beef and dairy if something isn’t done immediately, as indicated by information on the ‘TB Free’ website:

“An infection case in a cattle or deer herd can result in severe financial impacts on a farming business. These impacts arise not so much from livestock or production losses as from restrictions on a farmer’s ability to sell or move livestock. Bovine tuberculosis (TB) can have devastating emotional and financial impacts on individual farmers and the rural communities in which they live.”

Farmers will be compensated over the course of the eradication process, which is projected to cost them $278 million. However, the mental wellbeing side of things is more difficult to manage and will certainly be a real test of resilience for the industry.