Keith Woodford explains why the Mycoplasma battle is far from over; at best it is the end of the beginning

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By Keith Woodford*

There is a widespread belief in both the rural and urban communities that Mycoplasma bovis is well on the way to being eradicated from New Zealand. My response here is that there is a still a long way to travel before any declarations of success are appropriate.

In December, Prime Minister Ardern, no doubt choosing her words carefully and based on official advice, talked of ‘substantial progress’.  However, the broader tone of both MPI and DairyNZ messaging has led to parts of the media and then the general public taking a further step and concluding that the battle is almost over.  

On 18 December 2018, MPI sent a three-page letter addressed and mailed individually to New Zealand’s pastoral farmers, which oozed confidence. It started with the lead-in that “I’m pleased to update you on progress…” and then went on to say that “We’re confident about how the program is tracking’’.

The letter did concede that “There is still a long way to go to eradicate M bovis”. But the message was strong that the investigators and eradication teams are travelling faster than the disease can travel. The letter said “we are[now] identifying many at-risk farms before cattle have been able to mix, thereby reducing the risk of spreading the disease to other cattle on the farm”.

The messaging from DairyNZ was even stronger. On 17 December 2018, they issued a media release saying that “Today will come as a relief to many farmers”. They reported “encouraging progress” and said “Thank you to everyone involved… This has truly been a team effort”.

All of this does indeed sound as if we are heading into the final straight.  I say again, let’s not get ahead of ourselves.

To understand where we are at in the eradication campaign, it is helpful to recall that the disease was first identified in July 2017 on a South Canterbury farm, officially known as IP1.  MPI was caught napping, with no prior plans for eradication in the event of an outbreak. The response controller has said that he had to look on the internet to find out what was this surprise disease.

By December 2017, it had been found in Southland and elsewhere, with the first Southland farm identified as IP10. At that stage MPI thought that all of the new cases through to and including IP10 led from IP1. It was only around April 2018 that MPI belatedly came to the view that IP10 preceded IP1.

Throughout 2018, MPI has been increasingly insistent that there is no evidence the disease arrived prior to December 2015 and that all infections lead back to IP10. This belief is based on modelling of the rate of genetic mutation in the analysed samples.

Throughout the first half of 2018, the number of herds identified as infected spread out like a fan, first in the South Island but also in the North Island, with many of the infected farms clearly being linked to IP10 by known animal movements.

However, there is another group of farms, mainly in Canterbury but also in North Otago, for which the links are not readily apparent.

Accordingly, although the messaging from MPI has consistently stated that all new infections are linked by traces back to IP10, that is not the full story. There are about 10 farms where the links remains unclear.

This is not to suggest that the farms with unclear links represent a different outbreak, but it is very challenging to see how these links could get back to a single point-source infection as late as December 2015.

Those of us who are outside the official MPI system, but who know something of the animal movements on these infected farms, believe the logistics requite a longer period back at least one year further and most likely two years. Otherwise we cannot make sense of how the disease managed to travel so quickly and jumped from one farm to another.

The alternative to earlier arrival is that both IP10 and some other farms were each struck with an infection from a common source of semen. This is a definite possibility, but even then it becomes challenging to find disease transmission pathways that started no earlier than December 2015.

At times the debates on these matters can get down to semantics, such as the difference between ‘known evidence’ and ‘unknown evidence’, what information should be trusted, and also what constitutes ‘proof’.

For example, the molecular clock gives an estimate based on specific assumptions which may or may not hold.

Similarly, MPI has not always obtained the detailed and correct information from farmers that it needs. Sometimes this was because MPI officials did not ask the right questions.

On other occasions, the information got muddled as it passed up the chain. Subsequently, MPI officials became resistant to correcting obvious mistakes as they did not trust farmer information.

For reasons of space, I will use only two puzzle examples here. They are representative of others.

One of these farms was identified positive from a milk sample in the autumn of 2018. Subsequently, it was found that 2017-born calves were also positive, which leads to the 2016 mating being the most likely time of infection. However, on this farm there are no suspicious semen links and the most likely source is service bulls born in 2014.  

There is no proven link back from this farm to IP10, but a scenario linking back to IP10 in 2014 is possible. Other scenarios are also possible, but there is no identifiable scenario that is consistent with IP10 being a single-source infection as late as December 2015.

The second example is a dairy farm that went positive in the weeks leading up to Christmas 2018 with no forward traces from other infected farms. Once again, the most likely infection source would have been service bulls born in 2014 or at the latest in 2015.

For this second farm, there is a back-trace for a bull calf that was sold in 2016, so MPI can correctly say that it was a trace farm. But there are over 5000 trace farms in New Zealand, and back-traces tell us nothing as to how the disease got to the farm. They only tell how the disease may have left the farm.

The challenge for eradication is that very few farms show clinical evidence of the disease. In most cases it fans out without visual evidence.   Also, the tests are not reliable. Where has it got to that we don’t know about?

Currently, the most likely source of ongoing transmission is via service bulls and heifer calves. Given the starting point was in the Friesian breed, that is where the greatest risk lies. But it has also spread elsewhere. The Five Star beef feedlot is further evidence of that spread to other breeds. There lies an interesting story. 

The bottom line has to be that New Zealand is still in the early stages of its eradication campaign. It will be many years of monitoring and slaughter before victory can be claimed.


*Keith Woodford was Professor of Farm Management and Agribusiness at Lincoln University for 15 years through to 2015. He is now Principal Consultant at AgriFood Systems Ltd. His articles are archived at http://keithwoodford.wordpress.com. You can contact him directly here.

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22 Comments

Great news, they have the outbreak under control! Luckily for us, the experts are calling the shots. I have always thought they made the right call in trying to eradicate it, and I think there will be a lot of relieved farmers out there now.

Although it probably was the right and expensive call to eradicate MB, since we do not really know how it got here, what's to say it arrives again, or has already arrived again with imported embryos or semen.
Does anyone have the correct answer?

It got here through smuggled fresh semen, but proving it, is difficult. It can't get into the country through legal means. Hopefully the culprits get prosecuted to full extent as a warning to others, but they are very wealthy and may get away with it.

Maybe the dispatch labels got mixed up with the batches going to Hokitika Wild Foods Fest.

skudiv,
There has never been any evidence relating to importation of fresh semen, either legal or illegal. It is not a practical way of bringing semen into the country.
KeithW.

I come from a very unique point of view.

Not only was my property under Notice of Direction (NOD) for M Bovis, but I also work for a department of MPI.

We went through the whole process for several months on our lifestyle block with 10 young beef animals, which, to put it mildly was a pain in the ar*s. But being very familiar with the MPI media and spin machine, and the carefully worded statements, I knew when I was stone walled or led down the garden path by my ICP Area Manager. In situations like this I was fortunate in that I could pick up the phone, make contact with someone I knew in Wellington and get the real answer.

Long story short is that we tested negative and were issued a revocation notice, but not before one of the animals was slaughtered on the property on 9th Sept for autopsy. It was slaughtered on the property because as a 10 month old animal none of the freezing works wanted it. MPI instructed us to hire a home kill butcher to come to the property and slaughter and then dispose of the animal. We were told, of course, that all would be reimbursed to us by MPI...haha...yes of course we were told that.

Four months down the track we haven't heard a further word, except that the home kill butcher bill for slaughter is our responsibility and not MPI's, after the fact of course. We have received no compensation whatsoever despite submitting all relevant and requested forms the following week after autopsy.

So I am very interested to learn who exactly it is they are referring to, when I see MPI officials on TV stating "small and straight forward claims for compensation are being dealt with quickly".

Now for the kicker.

MPI will have someone assigned to trawling through commentary such as this to gauge public feeling. When my story is discovered, they will search for who had animals autopsied on my particular date, but then rather than ensure I receive my compensation quickly, the MPI machine will kick in and they will begin to apply pressure to stop me talking. This is our way. Welcome to New Zealand.

My daughter works at MPI in Wellington, she finds interesting but she's not in the M bovis department.

So you want to be compensated for the slaughter of "one animal"? How about the rest of NZ tax payer that has just forked out millions in compensation for your industry to try to eradicate M Bovis?
How about taking a deep breath and thanking us that you still have some healthy "animals" to farm and an export market!

I think his example was less about the getting paid, more about the empty promises, and bullshit they spin.

For my industry? Did you even read what I wrote? i own 9 yearlings, do you think I'm a farmer?

I thought I said very clearly what I do for a living.

We considered raising/grazing beef for our freezer when we had an LSB. Timing was just as NAIT was being introduced. We decided to lease our paddocks to neighbours instead. I figured it was the only way to come out with money in the bank :-). And... when the bull got out and mixed it up with the girls, we just had to call his owner! lol.

Ah ha I knew it. As soon as I kicked up a stink on social media they slapped a NOD on me. Yet other folks I knew that bought cattle from the same outfit havent ever been spoken to. Zip from MPI. Its a god dam joke. If there is a chance I had it, there is a chance they had it yet many trades of cattle later after more than a year exactly where this disease could be hiding is literally from the tip of the north to the butt of the south.
Thanks WOQStreet. Of course the bigger issue is how can they get away with picking on people who ask questions. Is that really how we work through our problems in nz? Oh yea it is. The govt put a security firm onto unhappy (literally) campers from the chch earthquake. Might as well be china or russia. Its disgusting.

Bureaucrats had two choices admit they stuffed up or hide the evidence. I don't see how NAIT can survive this.
If you have never had any practical farm experience it's easy to trivialise what is actually a very complex problem. We farmers are smarter than we look which can be deceiving.

Perhaps a series of mugshots of farmers with the intelligent one circled would be helpful...

Didn't Fred Dagg use to farm?

He was just great and worthy of a circle.
Any other possibilities?

Andrewj - hello to the new year. Boy you left yourself wide open suggesting farmers are smarter than they/we look. Just took a peek in the mirror - Shxt I hope I'm smarter than I look. No deception here sorry. One of the city folks will start throwing in big words l;ike oxymoron - farmers and intelligence HAHAHA. Now back to the cowshed...

I have to say I have been a fan of Country Calendar for the last 50 years so I think it’s a shame that industrial dairying has tarnished the dream.

I well remember some tv programme called something like the great nz iq test. They had teams of different jobs...farmers lawyers school teachers nurses. Asked them all manner of questions and yep the farmers came out on top. So that was it for me. We are clearly smarter than the average bear.

Plenty claim they are better than average. Myself included. Question is who of us is suffering from the Dunning Kruger effect?

I think it is rampant in the age of online and social media communication.

Can we have an update on local trade etc prices please.

Thanks!