Decreasing PI Numbers 07/01/2019

Encouraging increase in the disposal of BVD PIs by farmers


The number of BVD Persistently Infected (PI) cattle being retained on NI farms fell markedly during November and December 2018, according to the latest analysis. 

In two months, the total number of PIs alive dropped by more than 200, from 908 to 690 and the percentage of living PIs in the cattle population fell to 0.04% from 0.06%.  In addition, the rolling annual prevalence of BVD, which is a measure of the number of BVD positive animals over a 12 month period, has fallen to 0.46% from a level of 0.60% for the same period in the previous year.

PI retention relates to those PIs that are still alive 35 days after notification of their first positive result.  The number of retained PIs fell during the last two months of 2018 from 726 to 557.

These figures reflect the fact that more farmers are now making the prudent decision to destroy PIs, to the advantage of their farm businesses.  Many NI herd owners who have kept PIs have seen BVD infection persist into subsequent seasons, to their cost.  Given that BVD positive animals are restricted to their herds and that abattoirs are refusing to accept them for slaughter, the best option in these circumstances, in line with veterinary advice, is to minimise losses by culling the positive animals at the earliest opportunity.

In cases where farms have a history of BVD and where calves are tagged promptly after birth, many herd owners decide to put the positive calves down straight away, as there is a very high likelihood that the virus is persistently infecting their calves.


Note for editors:

1. AHWNI is responsible for the delivery of the Northern Ireland Bovine Viral Diarrhoea Eradication Scheme. For more information on the operation of the Scheme, please contact AHWNI (email, tel 028 7963 9333) or visit the AHWNI website