If you're a cow cockie in God's Own you could be forgiven for feeling under siege at the moment.

You've battled your way through several seasons of poor returns, The Beehive's been waving the stick at you for having too many cattle on your property with an inherent threat of cutting the size of the herd to protect our waterways and now you're battling disease.

Even though Mycoplasma bovis arrived here in July last year it seems to have been pretty well contained in South Canterbury and North Otago up until recent months.

This morning Jacinda Ardern's in the Waikato where she'll be talking to farmers about the scourge which has now hit the country's premier dairying province.


There's been a lot of finger pointing over the spread of the disease with Labour blaming National's inadequate cattle movement data system and with National accusing Labour of not taking the threat seriously enough and wasting cattle by destroying and burying them rather than putting them into the food chain.

But as one farmer observed to me, milking cows do not make gourmet cuts, hamburgers at best.

None of this is helping the hapless farmers who're watching their beloved animals suffer. Dairy farmers are attached to their cows and the effects of the disease aren't pleasant, including the painful mastitis of the udder and arthritis.

Not all infected cows get sick with some actually shedding the disease which makes its spread insidious with seemingly healthy cows infecting others.

Grant Robertson talked a lot in his Budget last week about having money in the kitty for a rainy day. Mycoplasma bovis could just be the storm cloud waiting to burst.

Thirty five farms across the country now have infected herds and that number grows by the day. The Beehive's talking about a billion dollars being spent to eradicate it with farmers expected to pick up 40 percent of it.

Further down the track there's a significant risk to the economy with dairy exports our biggest earner at more than $14 billion a year.

To put that into some perspective, dairy exports earn twice as much as meat, four times more than wood and earns nine times more than wine exports.

Just one country, Norway, is now free of the disease with other dairy producers learning to live with it.

Eradicating it is a costly exercise and it would seem almost impossible to achieve but given the importance of the industry to this country it's certainly worth trying, we can't afford not to.