New Zealand's dairy herd is free of a contagious viral disease, about 12 years after farmers started a national eradication campaign.
Enzootic bovine leukosis (EBL) disease is passed from mother to calf and also between cattle and can leave affected animals riddled with cancer. There is no evidence of it infecting humans.
The disease was eradicated in British dairy cattle in 1996, and an eradication programme was started in New Zealand the following year.
The EBL control scheme was the only industry-driven programme to have achieved complete control of a disease without any government intervention, genetic company Livestock Improvement (LIC) said today.
Herd infection rates were cut from nearly 10 percent in 1997 to below 0.1 percent by 2005, and intensive monitoring since then had led to no EBL-infected dairy herds being detected last year.
The scheme has been funded by an industry-good body, DairyNZ, with LIC carrying out the testing, which pioneered the use of pooled herd-test milk samples for cost-effective disease control.
At the height of the scheme millions of milk samples were screened each year.
An LIC spokesman said today that no systematic testing has been done on beef herds, and that natural-mating beef bulls brought into dairy herds remained a potential risk to EBL-free dairy herds.
The eradication scheme was recognised internationally and used by biosecurity officials for export certification of cattle, semen and embryos.