Expert view

NZ stock farmers need to up crop biosecurity measures

If you’ve ever been to New Zealand, you’ll be aware biosecurity is of national importance.

Beagles bound over bags on airport luggage carousels; arrival announcements remind visitors to declare all biological matter; posters and paperwork warn of $400 spot fines. And fines are regularly dished out, sometimes for just forgetting an apple lurking in the bottom of carry-on baggage.

But farmers are increasingly realising there’s only so much that can be done at the border, as a long line of recent incursions illustrates: velvet leaf, blackgrass, large white butterfly, to name but a few.

To stymie their spread, New Zealand’s Ministry for Primary Industries (MPI) is asking all farms to tighten internal biosecurity. In the case of cropping farms, there have been calls to clean machinery between farms and even fields. Harvest equipment is highlighted as a common vector, particularly for weeds, but cultivation tools are culprits too.

Many arable farms here grow seed crops so keeping the farm clean is of paramount importance. The seed crops aren’t just cereals for other New Zealand growers either: herbage seeds are a key part of most rotations and in some regions, notably Canterbury, high-value small seeds such as carrot, red beet and pak choi are also grown.

Most are for export and gross margins can be several thousand dollars per hectare higher than a standard cereal, so loss of contracts due to poor paddock hygiene is costly.

Clean machine message

The biosecurity message hardly needs repeating for them, but for others, to date, the incentive hasn’t been the same. For example, most livestock farms grow a crop or two each year, usually feeds such as kale or fodder beet for grazing over winter.

Most are reliant on contractors for field operations who in turn are under time and financial pressure to move between fields and farms as fast as possible. For them, the “clean machine” message is much harder to adopt, and their stock-focussed clients are less likely to call for it.

Photo credit: Shutterstock

Photo credit: Shutterstock

Then there’s the movement of livestock, which is what prompted me to tackle this topic today. Last July, MPI confirmed the first case of Mycoplasma bovis in New Zealand. As UK dairy and beef farmers will know, it’s an increasingly common cause of respiratory disease, mastitis and arthritis in cattle globally.

It’s also incurable so control hinges on prevention by testing incoming stock, and eradication through culling. Movement restrictions have been placed on the first affected farm here, but livestock are routinely moved freely and frequently between farms in New Zealand, so it had probably spread long before clinical symptoms emerged.

Biosecurity at home

In theory, these prior movements are traceable thanks to the National Animal Identification and Tracing tagging regime introduced in the wake of the UK’s 2001 foot-and-mouth epidemic. Time will tell.

If it is found to be more widespread, it’s another slice off New Zealand’s competitive advantage in dairy and beef, and a timely reminder that biosecurity begins at home, not the border.