Noel Byrne, farm manager of the Teagasc Ballydague farm near Fermoy, Co Cork, told the attendance of about 330 at the recent Animal Health Ireland (AHI) conference on the disease that Teagasc had the facilities to detect the problem early and implement appropriate measures — but BVD still affected reproductive and financial performance, and the impact was still being felt.
He advised farmers: “Know your BVD status. If there is no active infection in the herd, take appropriate measures to keep it out. If there is active infection, implement a control programme to include testing of calves.”
The research farm has 180 spring calving dairy cows plus replacements, used in trials to compare the performance of Holstein-Friesian, Jersey, and Jersey crossed with Holstein-Friesian cows.
Male calves are sold at three or four weeks, female replacements are reared on an outside farm.
All breeding animals have been vaccinated against leptospirosis, salmonella and BVD since the herd was established in 2000.
The farm’s intensive pregnancy scanning for research purposes revealed a pregnancy rate at 30 days to first service as low as 20% in three research groups.
The problem was traced to 12 Jersey maiden heifers purchased in April, 2005, which all tested negative for BVD.
Their calves born in 2006 were not tested for BVD. Calf health was poor in 2006. Of three ‘suspect’ weanlings born from the 12 heifers, two went in calf in 2007, and joined the lactating herd in 2008.
One died due to calving complications, the second produced a ‘healthy’ calf. But reproductive losses seemed to track the movement of this ‘suspect’ animal through various research groupings.
Testing in 2008 confirmed that three ‘suspects’ were PIs — which stands for persistently infected with BVD. Costs mounted from then.
In 2008, extra AI straws cost €1,044, delayed calving this year cost €9,900, and slaughtered PIs cost €4,500.
If your herd is hit by poor fertility; increased abortions, stillbirths, deformities; increased calf scour and pneumonia, always check for BVD, advised Noel Byrne.