The number of persistently infected (PI) BVD calves being born on farms has fallen by almost 50% in 2017, according to Animal Health Ireland (AHI).

With over 70% of this year’s calves now born, the rate has fallen from 0.16% to 0.09%, it says.

In addition, the speed with which PI animals are being culled has increased.

AHI says this progress has been made following the introduction of the targeted compensation for farmers under the eradication scheme, giving higher payment for removal within three weeks of a positive result.

The revision also restricts herds where a PI animal is retained for more than five weeks.

AHI says there are approximately 300 known PIs still alive, of which 44 have been retained in 30 different herds beyond five weeks – see map.

Risk

With breeding under way, cows are now entering the window of susceptibility to the disease between 30 and 120 days of pregnancy, AHI says.

This is the period during which the PIs that will be born next spring will be created.

“Clearly this risk is greatest for those herds which currently contain PIs, and the BVD Implementation Group strongly encourages their prompt removal.”

It also warns that herds free of infection take measures to ensure that the disease is not accidentally introduced.

At this stage in the programme, over 80% of herds have acquired negative herd status. A further 18% need only to test a small number of untested animals to achieve this status.

Herd owners can readily check their herd status, identify untested animals on the ICBF database and identify any animals of unknown status.

In the absence of appropriate biosecurity measures, pregnant females in these herds are also at risk. Therefore, any animals of unknown status should be identified and tested. To avoid introduction of the disease, farmers should ensure highest biosecurity standards.

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