Victoria was previously BTV-free, allowing cattle to be exported to countries that have restrictions on the virus, including China.
Australia and China signed new trade protocol allowing live export of beef cattle in July 2015 and the first major shipment was sent earlier this year, sourced from the previously BTV-free Victoria and South Australia.
For the next 30 days, part of northern Victoria will be a BTV zone, and livestock within a 100km of the property where BTV was detected will not be eligible to export to those countries requiring a BTV-free status.
Movement of these animals within Australia is not restricted.
BTV antibodies were detected in 12-month-old dairy heifers, meaning they were showing no clinical signs of the disease, only previous exposure to it.
Victoria’s chief veterinary officer Dr Charles Milne said Agriculture Victoria would observe herds in the area over the next three weeks to update the long term BTV status of the area.
“The purpose of the surveillance is to identify the potential source of the virus and determine if local spread of this insect-borne disease has occurred,” Dr Milne said.
“Agriculture Victoria staff will be contacting producers in the area to seek their assistance and make arrangements for on-farm sampling of cattle.
“Both the zone and surveillance activities are essential for providing assurances to our international trading partners and supporting Victoria’s, and Australia’s, valuable live animal export industry.”
It is unclear how the find will impact the dairy trade, given how heifer exports to China have dissipated in the past 18 months.
All ruminants are susceptible to BTV, which is a viral disease of livestock spread by flying insects known as midges, rather than from animal to animal.
Australian Dairy Farmers chief executive officer David Inall said it was important to reassure the Australian public that meat and milk were safe to consume.
He said bluetongue was not a transmissible disease, was not contagious between animals and did not affect people.
“These cattle were detected during pre-export testing,” Mr Inall said.
“There is no clinical disease in Australia, and routine testing of these animals showed evidence of a past infection.”
Mr Inall said the live export trade was an extremely valuable business for the Australian dairy industry.
“Over the past three financial years, Australia has exported more than 70,000 dairy animals each year, and around 95 per cent of these cattle were exported out of Victorian ports,” he said.
“China is a particularly important market with the trade exceeding $100 million per year, and was as high as $170 million in 2013-14.”
Mr Inall said the United Dairyfarmers of Victoria and Victorian Farmers Federation were doing a fantastic job in ensuring that the farmers on the ground in and around Echuca were kept up-to-date.
“Australian Dairy Farmers is hopeful that this process of additional surveillance and testing is smooth,” he said.
“We look forward to Australia continuing its excellent relationship with key importing countries, such as China, who we are sure will again soon enjoy the quality of Australian dairy cattle.”