Find and cull PIs in your herd to get the upper hand on BVD
Published 18/10/2011 | 05:00
One of the first bovine diseases that Animal Health Ireland has set its sights on eradicating is BVD (Bovine Viral Diarrhoea).
If you blood test cattle on most dairy or beef farms, you will find that a lot of them will have antibodies against BVD.
This does not mean you have a problem though. All this tells you is that those cattle came in contact with the virus at some point, were probably sick for a short while, got over it and in the process developed antibodies against it.
However, the farms that do have a problem are those that have an animal that is a carrier of the disease itself and are shedding it daily in huge amounts. These are called persistently infected, or PIs.
These PI animals must be identified and got rid of. If not, they will continue to infect stock on the farm which can lead to a lowering of their immunity, allowing in many other diseases which cause hardship and severe economic loss.
Many PIs will show signs of the disease and die before they are two years of age. However, we are told that up to 30pc of PIs will never show any signs and can stay in a herd for years causing problems. So how can they be found?
The Animal Health Ireland plan to find PIs was to begin towards the end of this year. It may be delayed because of some technical difficulties but this does not mean that farmers themselves cannot start the screening process on their own farms.