Culling of cows is planned among measures to target pocket of Mycoplasma bovis infection

The Ministry for Primary Industries announced today it will begin culling cows on a huge feedlot, near Ashburton, which is infected with Mycoplasma bovis.

Stock will be culled on eight farms in the high-risk area.   Six farms in an area designated “at-risk” will undergo increased testing.

Reporting this news, RNZ recalled the Government’s announcement in May that after working to rid New Zealand of the disease, the feedlot was the only infected property remaining.

But two more properties have tested positive since then .

The Five Star Beef feedlot in Ashburton, owned by ANZCO Foods, farms about 12,000 cattle.

Culling will begin on the feedlot in mid-October and nearby farms must be “depopulated” by mid-January, a press statement from  Biosecurity New Zealand says.

The Mycoplasma bovis (M. bovis) eradication programme is targeting the sole pocket of confirmed infection with culling starting on a Mid-Canterbury feedlot and strict new biosecurity measures for the surrounding area, says programme director Simon Andrew.

Information from the Government’s nationwide testing programme suggests M. bovis infection is isolated to a small area in mid-Canterbury, where there are infected properties, including the feedlot.

Biosecurity NZ staff are striving to establish the exact transmission route, but at present this remains unclear.

“Without a precise understanding of why this is happening, we need to take a different approach to protect cattle and farmers in the area,” Simon Andrew says.

“We acknowledge the role local farmers have played in helping us continue to better understand the situation, and to bolster this, we are bringing in extra technical advice.

“Although we are at the tail-end of this outbreak, it is possible we may find other infected properties in other parts of the country in the future and so we must remain vigilant and maintain our nationwide surveillance programme.”

At the height of the programme there was a peak of 40 confirmed properties across the country

This has been reduced to three farms.

“We are committed to hunting down the last remaining infection,” Mr Andrew says.

“There’s been 275 confirmed properties to date out of 30,000-plus farms in New Zealand.”

Mr Andrew says the M. bovis Programme, alongside industry partners DairyNZ and Beef + Lamb New Zealand, will:

  • Work with the feedlot’s owners, ANZCO, to start progressive depopulation of the property from October 13
  • To coincide with that depopulation, a Controlled Area Notice (CAN) will be introduced for the Wakanui area, affecting 14 cattle farms (three of these properties are owned by ANZCO). The CAN map is available on the M. bovis Programme’s website
  • As part of the CAN, all properties in the high-risk area will be depopulated by mid-January 2023
  • A round of testing and census will be carried out for farms in the low-risk area of the CAN

“The CAN steps up the already tight controls in the area as we think it’s important to take all possible steps to ensure this pocket of infection is contained and the progressive depopulation of the feedlot successful,” Mr Andrew says.

“As part of the CAN, all properties with cattle in the high-risk area will be depopulated by mid-January 2023, or earlier, followed by a standdown period of 2-3 months to allow these properties to be cleaned and disinfected.”

The programme partners would work closely with the small number of impacted farmers in the area and compensation would be provided where required.

“We know the CAN will be extremely challenging and disruptive for a small number of farmers in the area and we will support them through this process,” Mr Andrew says.

“Since the start of the programme, M. bovis has predominantly spread by animal movements and we ask farmers to continue keeping their NAIT records up-to-date to protect themselves and others.

“It’s easy to get complacent, especially with low numbers across the country, but now is the time where we must be more cautious than ever and that’s why we are taking these prudent steps.”

There has been no confirmed infection outside of mid-Canterbury since July 2020 and  Biosecurity NZ’s extensive nationwide surveillance will continue for several years as it moves to the “proof of absence phase”.

“Our bulk milk test programme is going well, with no unexpected finds in recent months. August 2022 is on track to be the first August since 2018 with no confirmed infection detected via bulk tank milk surveillance.

“While this is positive, it doesn’t mean the job is done. It is likely that we’ll find more confirmed infection before we declare eradication successful. When we find any infection, we will deal with it.”

A controlled area notice is used under the Biosecurity Act to limit the movement of animals or risk goods from a specified area. These notices have been used in a range of biosecurity responses, including successful eradications of fruit fly and pea weevil.

Biosecurity NZ expects about 14 farms with cattle will be impacted by the CAN — eight in the high-risk area and six in the at-risk area. There are cropping farms in both areas, but the impact is expected to be minimal as those properties do not farm cattle.

The Mycoplasma bovis Eradication Programme began in May 2018 and is jointly funded by Government (68%) and DairyNZ and Beef + Lamb New Zealand (32%).

The cattle farms impacted include a mixture of dairy and beef grazing, and beef drystock. Some cropping farms are located within the CAN.

Key numbers:

  • 3 current infected properties (275 since M.boviswas found)
  • Nearly 3 million tests have been completed
  • $230 million has been paid out in 2780 claims
  • 178,000 cows have been culled
  • In the past year less than 2 per cent of farms with bulk milk tank detects have gone positive
  • The cost of the Programme, as at 30 June 2022, is $588m.

Sources:  RNZ and Biosecurity New Zealand

Author: Bob Edlin

Editor of AgScience Magazine and Editor of the AgScience Blog