Biobest Laboratories Ltd

Infectious Bovine Rhinotracheitis (IBR)

The Disease

IBR virus causes a severe respiratory disease, which may progress to a fatal pneumonia. Once an animal has been infected, it remains a carrier for life, with periods of stress (such as movement, starting a bull in work or bringing in for the winter) triggering shedding of virus. Several different strains exist which also cause reduced fertility/abortions, a drop in milk yield and inflammation of the vulva/prepuce.

The Effect in Your Herd

Your herd may experience reproductive problems such as failure to conceive and abortions, as well as severe pneumonia outbreaks amongst calves. In addition many European countries are IBR free, and animals exported to the EU will generally have to come from Accredited-free herds.

The Route of Transmission

The virus is spread by respiratory tract and eye secretions, and also by semen. Separate cattle with 3 metre fencing to eliminate nose-to-nose contact from neighbouring farms or between separately managed groups. Infected bulls can shed the virus in semen. Vaccination can be an option; as a marker vaccine has been developed which is distinguishable from wild IBR infection.

Disease & Status
Animals to be tested
Action required
1. IBR: First herd test
The whole herd over the age of 12 months is tested. If this test is clear, the test is repeated within 1-12 months to gain Accreditation test 2. If positive animals are found, these are removed*, and the next test is 3.
2. IBR: Second herd test (if the first test is clear). The whole herd over the age of 12 months is tested. If this test is clear, the herd becomes Accredited for IBR. Test as per 4 yearly to maintain Accreditation.
3. IBR: Further herd tests (if the first test showed active IBR infection).  The whole herd over the age of 12 months is tested. If positive animals are found, these are removed, and the next test is a repeat of 3, to be repeated yearly until a clear test is achieved.
4. IBR: Maintenance of Accreditation  A statistical sample (see Appendix B) of animals 12 months of age or older must be tested. Breeding bulls must also be tested, along with any animals that are not home-bred (unless they have come from an IBR Accredited herd). Dairy herds must also conduct a quarterly bulk milk test.  Repeat yearly to maintain Accreditation.
5. Dairy Milk Monitoring scheme Bulk milk tank sample; if more than one tank is present, a sample must be taken from each one.  Repeat at 3 monthly intervals.

*If too many animals require removal, there are other options, e.g. vaccination, which may be used, and this will be discussed in detail when the results are reported.