The Government decision to eradicate rather than contain Mp. bovis has the merit of drawing a line under the first stage of the disease outbreak, writes Allan Barber.
There were three options under consideration: eradicate, manage or do nothing; the third was clearly not seriously considered, but there must have been a serious debate between the first two. In the end the eradication course of action was chosen because it gives ‘the best shot’ at eliminating the disease to the benefit of the New Zealand agricultural sector, particularly the dairy industry, and the economy.
The other factor which weighed in favour of the chosen option was the Ministry for Primary Industries (MPI)’s cost estimate of $886 million in contrast to $1.2 billion from attempting to manage the disease, although at any point along the way it may prove necessary to accept eradication is not possible and management will then become the default option. The likely first trigger point for a change will come in October/November after calving when cows are at their most stressed and liable to show signs of Mp. bovis. The third option of doing nothing has been estimated to cost $1.3 billion in lost production over 10 years as well as continuing productivity losses.
The difficulty of deciding how to tackle the disease is made worse by the inability to discover how it got into the country in the first place. There are seven pathways under assessment, of which the most plausible – importation of livestock – has almost been eliminated because nearly all imported cattle come from Australia and the Mp. bovis DNA strain of the New Zealand outbreak is not the same as Australia’s. So the options are six relatively unlikely pathways, including imported semen, veterinary medicines, machinery and movement of other animals. It will then be necessary to develop a risk management plan for each pathway.
My first question about the disease since it was discovered has been ‘how on earth did it get here?’ Until this is known, it really feels as though MPI is floundering around in the dark, in spite of all the scientific advice. Although the disease is claimed not to have been discovered until December 2015, there are suggestions it may have been present, if unidentified, as far back as 2010. It is still critically important to hopes of long-term eradication that the origin of the specific strain of Mp. Bovis which somehow entered the country is traced.
A significant influence on the decision to continue with eradication or a move to management will be the spread of the disease beyond those farms identified as having a link to the original property where it was first discovered. The situation appears to have settled down after the recent spike in infected properties with a larger batch of test results becoming available. But the rate of discovery and the specific locations will be closely monitored.
The beef industry is seen as much lower risk than the dairy sector because the outbreak originated on a dairy property and beef cattle are under less stress than dairy cows. But any change in this trend would require a serious re-evaluation. The most likely cause of Mp. bovis finding its way onto a beef property would be through dairy beef calves, but again hopefully these calves won’t be allowed to come off an infected farm or one which has had contact.
A friend of mine with a small sheep and beef farm was heavily involved with the BSE outbreak in the early 1990s in the UK which was badly handled, because the Government tried to downplay the risk to public health, as well as attempting to reduce corporate losses. At the time, MAFF was the UK agency responsible for farming, meat processing and rendering, but it was also responsible for protecting public health from agricultural products and processes which gave it a conflict of interests. Fortunately Mp. bovis does not present any risk to public health which makes it far less serious than BSE.
However, this Government is determined to avoid such conflicts of interest, choosing a brave course of action which will cause great pain and stress to the relatively small number of affected farmers, but will, it is to be fervently hoped, avoid a more widespread disease outbreak. Only time will tell if it is the right decision.