New Zealand on Monday ordered the culling of 1,26,000 cows in the largest mass animal slaughter in its history to try to eradicate the Mycoplasma bovis disease, AFP reported. The decision was a “tough call” but had to be made because the alternative was the spread of the disease across the country, Prime Minister Jacinda Ardern said.

The disease causes udder infections, pneumonia and arthritis, but does not affect milk and meat for human consumption. The country will spend 886 million New Zealand dollars (Rs 4,150 crore) over two years on the effort to eradicate the disease.

The decision was taken to “protect the base of our economy – the farming sector”, Ardern said. “This is a tough call – no one ever wants to see mass culls,” she said. “But the alternative is the spread of the disease across our national herd. We do believe we are taking it on at a point that it is possible to eradicate and more than 99% of farms don’t have it and we want to protect them from having it.”

New Zealand has already culled 26,000 cattle in the 10 months since the disease was discovered. It has been found on about 40 farms so far, but 192 farms are likely to be involved in the culling.

Many healthy cows will also be killed. “The majority of animals that we do cull in New Zealand are all healthy,” said Agriculture Minister Damien O’Connor. “This is a necessary, unfortunate part of not having a test that clearly identifies the individual animals yet.”

New Zealand is the world’s largest exporter of dairy products, and produces 3% of the world’s milk.