SPECIAL REPORT - BOVINE VIRAL DIARRHOEA
Disregarded disease
COULD BE ELIMINATED
By Karen Trebilcock BVD Free New Zealand is frustrated there is still no nationwide BVD (bovine viral diarrhoea) eradication programme. “BVD control has been put on the backburner over the past few years while farmers and industry have had to respond to other high priority issues like M. Bovis and Covid,” Massey University associate professor of veterinary epidemiology Carolyn Gates says. “Because there are no human health risks from BVD and currently no international trade restrictions, it has been very difficult to get engagement around national BVD control.” BVD Free, a group of mostly vets and university researchers, finished modelling last year a cost analysis and road map which showed the disease could be eliminated in New Zealand within seven years. It’s estimated BVD costs the country $150 million each year in losses and another $42m for finding animals with the disease and vaccinations. For infected dairy herds the cost is about $22 per cow per year on average over the five years of an outbreak and $44 per cow in beef herds. With testing data still low in NZ, it’s thought between 15% and 25% of dairy herds and about half of beef herds are infected and there will be between 5% and 10% of new herds infected this year. “The modelling we’ve done shows that if all dairy herds tested their keeper calves to get rid of persistently infected animals and all beef herds vaccinated their mixed aged cows and replacement heifers to prevent the creation of new persistently infected animals, national eradication could be achieved at a cost $350 million over the seven years with a total benefit of $645 million back to industry. “Any additional measures that farmers take to improve onfarm biosecurity could make
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‘Any additional measures that farmers take to improve onfarm biosecurity could make eradication even more financially attractive.’
Carolyn Gates, associate professor of veterinary epidemiology, Massey University.
eradication even more financially attractive,” Carolyn says. In comparison, the government, DairyNZ and Beef + Lamb NZ are spending $870m over 10 years to eliminate Mycoplasma Bovis. “We are hoping BVD will eventually be added to the list of eradicated cattle diseases in New Zealand such as Brucellosis, Hydatid disease and EBL as well as M. bovis. “However, in the last few years, whenever we have tried to get government or industry engagement in progressing the infrastructure development to support national control, there have always been other issues higher on the agenda. First it was M. bovis and now it’s also Covid. “I think the drive to achieve national control really should come from farmers and veterinarians, but these groups have also been under significant stress from recent events,” she says. “Having BVD certainly doesn’t help any farmer’s situation and some of our most-committed supporters are unfortunately folks who have witnessed the devastating effects of a BVD outbreak first-hand. These are the guys picking up the phone to ask us why we aren’t doing more as a nation to control BVD.” Carolyn says simple and effective tools to support national control such as getting an animal’s BVD status integrated into NAIT has also not gained traction. “In the UK, farmers can register their herds and when a calf is tested, its status is recorded on a national database automatically by the diagnostic lab. “It means future purchasers of the animal can access that database and see it verified that the animal is not a carrier of the disease. “In New Zealand, purchasers have to rely on vet certificates or more often just the other farmers’ word, but the BVD status could easily be an extra column on NAIT records.
Dairy Exporter | www.nzfarmlife.co.nz | October 2021
