Tasman district is within touching distance of reaching a milestone in the battle against bovine tuberculosis, a scourge of cattle and deer farmers.
The district’s farms could be free of the highly infectious disease, which is spread principally by possums, provided the one remaining infected beef cattle herd, north of Murchison, returns a second clear test in December and no new cases emerge in the meantime. . .
However, farmers and animal health authorities warn that there can be no let-up in efforts to tackle the disease, which remains a threat to New Zealand’s reputation as a top agricultural exporter.
Roy Bensemann, a Sherry River farmer who chairs the Tasman TBfree committee, says he has seen the impact TB has wrought on farms in his valley.
“It highlighted to me how devastating it can be for farmers, financially and emotionally.”
Not only is there the social stigma, it severely restricts what farmers can do with their stock, which cannot be moved or sold, unless it is to the freezing works for slaughter at much reduced values.
It means dairy farmers have to either buy in supplementary feed or find winter grazing close by, and they cannot sell their heifers.
It can take a long time for restrictions to be lifted, with two clear herd tests needed at least six months apart.
“Quite often, other infected animals can turn up as you go through the process of getting the whole herd blood tested.”
There are also cases where infections in older animals in particular don’t show up through testing and are only discovered when they are culled and slaughtered. . .
That’s what happened on our farm.
We bought a herd of cows from the West Coast. they’d been tested and declared TB-free but a few years later a test came back positive in several cows.
They had to be killed, some had the disease, some didn’t.
The herd was tested and declared TB-free again but the next season another cow tested positive.
Eventually an older cow dried herself off mid-season and was sent to the freezing works where they found she was riddled with TB event hough she’d never tested positive.
New Zealand already runs one of the most successful TB control programmes in the world, which has made much more progress than predicted, with new research and technology promising even better outcomes, Mr Bensemann says.
It has the added spinoff of protecting native bird and plant populations. . .
Danny Templeman, South Island relationship manager of OSPRI New Zealand, which recently took over TB control from the Animal Health Board, says success in Tasman has been built on getting possum numbers down to one or two per 10ha in buffer zones up to 20 kilometres deep around Kahurangi and its bush margins.
Aerial poisoned bait drops in more remote parts of the park have proved more effective, and for longer than expected, which has allowed the number of ground control operations to be reduced.
“We have been able to get in front of the disease and push it back into the bush.
“But we need to continue this effort.”
A concerted effort is needed and must be maintained to eradicate the disease which is a risk to human and animal health, native flora and birds.