To demonstrate the benefits and process of the BVD stamp it out scheme, I have put together a case study from one of our dairy farms. This 150-cow dairy was not vaccinating prior to the scheme and their BVD status was unknown before signing up.
The first step is to register your farm onto the scheme – this involves coming to one of our BVD meetings for a beer and lunch while filling out a form with your CPH and SBI numbers. The initial meeting covers the disease process, signs and financial implications of BVD. Following the meeting, all registered farms are then entitled to a free visit where we will take 5-10 blood samples depending on group sizes. On this dairy, we took 10 bloods from 9-month-old calves, and tested these for antibody (exposure). The results came back with 9 animals exposed to the disease and one without exposure.
This result showed us that active infection was present in the herd and raised our suspicions that the one negative animal could likely be a PI (persistently infected animal). Our first steps going forward were to contact the SAC to gain approval to access the further £440 PI hunt testing budget. This was approved due to the high exposure and so the hunt began! Initially a bulk PCR milk test was undertaken (this looks for actual virus DNA in the milking cows and would flag up any PI’s in the milkers). The bulk milk came back negative and allowed us to focus resources and money on just bleeding heifers, dry cows and young stock to find our PI(s).
The first animal tested for BVD antigen (antigen looks for animals with circulating virus) was the 1 animal out of our initial group to come back as negative to exposure. This returned a positive antigen and therefore confirmed a PI was present. 96 further animals were then blood sampled and these were also then tested for antigen. Of these, another animal was identified as a PI. Once the two PIs were removed from the herd, we could be sure we had removed current sources of infection and we began annual vaccination of all breeding stock with Bovela® BVD vaccine. Tag and testing will also be performed on calves born for at least the next 12 months to ensure no more PIs are born before the vaccine has protected an entire pregnancy. The final step is a closing meeting with most of the initial farms that attended the first cluster meeting with you. This will be an opportunity to share thoughts, future planning and prevention protocols.
This case highlights the main advantages and benefits available to you from this scheme:
• All testing and investigation are completely free of charge!
• If your BVD herd status is unknown, this is a great way to identify it
• If we find circulating virus, the resources available will help you eradicate it quickly
• Vet time is free to discuss future planning and prevention protocols going forward
BVD is a completely avoidable and eradicable disease and by taking part in the scheme you can help the drive to eradicate it in England. If you think you may have a BVD problem on your farm, contact the surgery to speak to one of our farm vets.
Written by Will Davey.Back to news