TB or not TB

Tasman District is on the verge of being declared TB Free:

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.

2 Responses to TB or not TB

  1. Gravedodger says:

    Dread is the dominant emotion when the TB tester comes to ‘read’
    a couple of days after the sensitising injection is placed.

    We lived and farmed in an endemic TB area of the Wairarapa, with a registered Horned Hereford Stud producing Dairy Bulls and every, but every annual (in endemic areas annual, non endemic every three years) TB Test of our 300/400 animals was the single most stressful event imaginable.
    An Income hit from a single reactor potentially massive and hence unthinkable.
    It is often the last raceful that throws up the “reactor” to the skin test (sods law I guess), the absolute relief when the tester announces all clear is palpable.

    Twenty years withstanding every one of our nine neighbours go in and out of TB free status while remaining free ourselves was a bit like living next to a feul depot, never “if” only “when” always the present basic emotion.
    False positives from non threatening “Avian” TB always an added threat as they were only ruled out with a more elaborate retest or slaughter.

    The greatest at risk problem facing districts such as Tasman is the potentially very high concentrations of Possums on bush fringes, where grass makes for a great diet adjacent to a bush homeland complete with chaotic sleeping arrangements.
    Overcrowding allowing rapid spread of contact TB within the possums and thenwith them feeding by travelling over dewy grass with superating infected lesions contaminating pasture for cattle almost a “perfect storm” scenario.

    Significant control of Possum numbers on bush fringes is very successful as lower density populations inside the fringes reducing contact infections and healthier animals are a much reduced problem although feral Deer can be another problem.

    That goes a long way to explain my almost evangelical fervor in support of 1080 and the recent support from the Environment Commissioner even now that we “have no skin in the game”.

    Great ‘news’ from the front in Tasman.

  2. Roger Barton says:

    GD…I don’t know at what stage you left the Wairarapa region but we have gone from 360 herds on movement control down to nil! Amazing work by all concerned. Our own patch against the ranges was always a hotbed of TB but with the 1080 programme we are now almost opossum free..shot one las night..first in 2 years for me.
    As a plus from the work on possums our bird life has leapt exponentially.16 tuis in 2 kowhais last week….unbelievable. So much for the bush “falling silent” according to the anti brigade.

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