Across the country there is a research project underway looking into BVD in beef herds and if it can be eradicated from New Zealand. So far the project has involved blood sampling 75 beef herds from across New Zealand who have not been doing anything to manage BVD, before mating in late 2017. Of these, 32 herds (43%) were classified as being actively infected with BVD and 382 animals (34%) showed evidence of prior infection with BVD virus. In an actively infected herd there is a very good chance of having
persistently infected (PI) cattle present. In about a third of actively infected herds, less than half of the R3 heifers were immune to BVD prior to the start of mating. This means that if any of these animals were exposed to BVD during the mating period, they were at risk of aborting or creating PI calves. From some early-scanning herds that have been re-sampled we know this has happened. This
can have big economic impacts on your herd by reducing reproductive performance for the current season (low in calf result) and by keeping the BVD transmission cycle going if new PI animals are born into the herd later this year. This also suggests that leaving PI calves in the herd as “natural vaccinators” may not be effective if the virus spreads too slowly to expose all at-risk breeding animals before the start of mating. Slow spreading of the virus is more likely in extensively farmed beef herds. The project is now following these herds to see what has happened to the scanning percentage and trialling different management options. You will be able to track the progress of the BVD Free research studies and get access to more information about controlling BVD in your herd through our new project website (www.bvdfree. org.nz), which is scheduled to go live soon. If you have any questions about BVD, have a chat to your local VetEnt vet. 

08 May 2018, 20:08
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