It is a “myth” to suggest that retaining a calf which is persistently infected (PI) with bovine viral diarrhoea (BVD) will act as a vaccine for the rest of the herd, the body responsible for delivering an eradication scheme in NI, has said.
In a statement highlighting the issue, Animal Health and Welfare NI (AHWNI) said a PI calf exposes other cattle to the virus in an “uncontrolled and unpredictable way”.
Ultimately, a PI animal will spread infection, leaves animals on the farm increasingly susceptible to other diseases and will result in the birth of more PI calves.
An AHWNI survey of 72 farmers who had a BVD positive result found that 21% did not go on to vaccinate their herd after the first case.
“Vaccination is an insurance against further BVD cases as well as against the fertility problems, abortions and immuno-suppression the virus causes,” the AHWNI said in the statement.
