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The percentage of tissue tags found to be empty when opened for BVD testing in laboratories is similar across all three brands of cattle tag now available on the Irish market.
This finding was presented by the Department of Agriculture to the most recent meeting of the BVD Implementation Group chaired by Animal Health Ireland.
The empty rate has attracted some attention in 2017 because it is close to double that of last year. The rate is still very low at just 1.01% of all tissue tags applied in calves. That equates to 22,761 tags to date this year.
According to Dr David Graham, chief executive officer of AHI, an empty result is reported when a tissue tag received by a laboratory has no tissue, or perhaps has insufficient tissue.
“It means the lab test cannot be done. It is reported by the lab to the ICBF and they notify the herd owner by SMS. We in Animal Health Ireland get a weekly update on the figures.”
The herd owner must then retest.
Negative
“The issue is you need a negative test before an animal can be sold. So it could have an immediate impact on a dairy herd planning to sell calves.
"In addition, it could eventually put the farmer’s negative herd status at risk, and, with that, access to lower-cost testing. But a farmer will get reminders to retest before that is triggered. The majority of herds, 86%, have access to lower cost testing.”
He said: “Obviously we’d rather see no empties. We recognise there is cost and hassle for the herd owner and that’s a concern. But given the empty rate is low and the ability to retest, it doesn’t threaten the effectiveness of the BVD programme.”
Lowest ever PI numbers
The number of PI calves alive on farms is now the lowest it has ever been, David Graham said.
He attributes this to the range of measures designed to speed up removal in 2017, including the refocusing of financial supports, the automated restriction of herds where PIs are retained for more than five weeks and veterinary investigations funded through the Rural Development Programme.
AHI’s focus is on having PI calves removed from herds as quickly as possible, to prevent spread of BVD virus and thereby lower prevalence of the disease.
Counties with no PI calves
“Currently there are 77 PIs alive. I’m confident that is the lowest number ever. At the moment, 14 herds have PIs alive more than five weeks after the initial test.
"Four counties had no PIs alive in November. They were Carlow, Louth, Dublin and Sligo. Of course it is almost inevitable that some PIs will be born in those counties next spring. But all the evidence is that PIs are being removed more quickly.”
The result of this will be seen next year, he said.
“Hopefully, these changes will lead to creation of fewer PIs this year to be born next year. That will continue the lowering of prevalence of the disease.”
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