‘IBR virus can cause a milk production loss of over 9kg’
IBR has become a significant issue in herds over the past few years, according to Kieran O’Mahony of XL Vets and the Glen Veterinary Clinic in Co. Tipperary.
The IBR virus can have a negative impact on herd performance by reducing the milk production of dairy cows, said the XL vet.
“It has been estimated that an animal infected with the IBR virus can have a milk production loss of over 9kg over the course of a 14-day infection period.”
The virus can be easily spread and can travel up to five meters so even closed herds face the risk of becoming infected from neighbouring herds.
“The IBR virus is very contagious and can travel in the air up to three to five metres so contact with neighbouring stock increases the risk of exposure to the virus.”
However, O’Mahony added that bought-in stock are the most common way of introducing the virus into the herd, but it can also be spread via people or contaminated farm equipment.
Creating a vaccination programme
According to O’Mahony it is essential to vaccinate naïve animals in the herd. These animals will shed the most virus and will also show the greatest clinic signs of infection.
“I have found that sitting down with my clients and planning a control strategy with them for IBR has been an essential and successful part of our herd health service.”
He also advised farmers to consider using blood sampling and bulk milk testing as a process of identifying the IBR status of the herd.
“When devising a control strategy for IBR with my clients I generally advise strategic blood sampling so that we can establish whether the prevalence of IBR in the herd is low, medium or high.”
The XL vet added that approximately 60% of his dairy and 40% of his beef clients now use a vaccination programme to target IBR outbreaks.
“I have found vaccination with Bovilis IBR Marker Live to be a very successful part of the overall control plan I devise with my clients.
“I advise a programme where the herd is vaccinated with this live vaccine every 6 months,” he said.
According to O’Mahony, this regime is simple, straightforward and easy to implement.
The XL vet added live vaccines tend to produce better results than inactivated or dead vaccines.
“This is because cattle that have been vaccinated with a live IBR vaccine will have a greater reduction in temperature, a greater reduction in the clinical signs of IBR and will shed less IBR virus than cattle that have been vaccinated with an inactivated vaccine.”
In association with MSD Animal Health.