WELLINGTON, New Zealand (AP) — New Zealand is on the verge of eradicating a painful disease from its herd of 10 million cattle after a four-year campaign that cost hundreds of millions of dollars and resulted in deaths of more than 175,000 cows.

Agriculture Minister Damien O’Connor said on Thursday that 271 farms had been cleared of Mycoplasma bovis and only one farm in the country was still suffering from the bacterial disease. New Zealand would be the first country to have managed to wipe it out completely.

In an interview with The Associated Press, O’Connor said it had been a traumatic process for the farmers involved. If an infection was discovered on a farm, even healthy cows were killed to ensure that the disease was eradicated.

“I would say every farmer was very upset that they had to see their herd slaughtered,” O’Connor said. “These are people who have strong connections, commitment and investment in their animals.”

Agriculture is the country’s main source of export revenue and is vital to its economy. When Mycoplasma bovis was first discovered in New Zealand in 2017, it sparked a massive government response, which concluded there was a unique opportunity to eradicate the disease before it spread widely. .

Found in cattle in the United States and Europe, Mycoplasma bovis is a bacterium that can cause mastitis, pneumonia, arthritis and other painful conditions in cows. The bacteria is not considered a threat to food safety, but the resulting illnesses in cows can cause distress and lead to lower milk and beef yields.

O’Connor said the last farm to get the disease was a feedlot where cattle came to be fattened up before slaughter. He said the farm would be cleared of the disease later this year and it would take several more months of nationwide surveillance to declare victory.

He said the New Zealand campaign was groundbreaking.

“This is extremely important, and I think there are other countries that have M. bovis that will also be looking to learn more about their eradication options,” O’Connor said.

He said the final cost of the eradication program is likely to be slightly less than the budgeted NZ$886 million ($580 million), money that has been spent on operations, monitoring and compensation. . The government picks up most of the bill, with farmers and the cattle industry also contributing.

It is unclear how the disease first entered New Zealand, which has strict biosecurity controls. One theory is that it happened in imported bull semen.

Fiona Doolan-Noble, a senior researcher at the University of Otago who studied the eradication program, said government officials could have done a better job at first by listening to the expertise of local vets and farmers, but she thought communications had improved over time.

She said there was a chance the disease could re-enter New Zealand, although the country’s experience not only with the disease but also with COVID-19 has raised awareness of the need for stricter biosecurity measures. .

New Zealand has 6.3 million dairy cows and 4 million beef cattle, making its total herd twice as large as its human population. Dairy is the country’s biggest export, with much of it sold in China where it is used in infant formula.

Prime Minister Jacinda Ardern said the government’s partnership with agricultural industry players had been crucial to the success of the scheme.

“When we took our one shot to eradicate, we did so to protect our national herd from a painful disease, our economy from a brutal shock and our rural communities from widespread anxiety,” Ardern said.