British Simmental Review 2018

effective when used prior to exposure as prevention,
rather than as control following infection. An assortment
of vaccines, vaccine courses and routes of administration
are available. There are separate indications for managing
abortion and foetal infection with IBR, and also for calves
younger than three months old. Please seek veterinary
advice if this applies to your herd.
There are two main types of vaccine; live or inactivated
(dead). Within each category, there are marker and nonmarker
vaccines. A live vaccine is often used intra-nasally,
or into the muscle. The intra-nasal route will ensure
quicker protection, but the antibody levels are unlikely to
be as high. As the virus is live, it can theoretically replicate
in the animal and ‘infect’ unvaccinated animals. Inactivated
vaccines are never given intra-nasally, and cannot replicate
within the animal. Antibodies are generally high and long
lasting.
Marker vaccines were developed to allow differentiation
between cattle that are vaccinated and those that
have been exposed to wild-type virus. It’s impossible
to differentiate the non-marker vaccines from natural
exposure on a single blood sample. An animal vaccinated
with a marker vaccine and exposed to wild-type virus will
produce wild-type and vaccine antibodies. Antibodies
to IBR can be passed to the calf via colostrum. This will
have an impact on when calves are vaccinated, and blood
samples taken from calves could be antibody-positive for a
number of months.
The IBR vaccinated and monitored free
programme
This is applicable to herds which cannot achieve
full double fencing biosecurity requirements and
demonstrates that the herd is operating a marker
vaccination programme and is free from IBR infection
based on gE antibody testing. It is a lower level of health
status compared to IBR accredited free herds.
• With permitted exceptions all stock over 12 months
old should be marker vaccinated for IBR.
• Sale animals or animals for export or potential
AI should NOT be marker vaccinated and the
vaccination protocols should be discussed with your
vet.
• Two herd tests are carried out between 4 weeks and
12 months apart
• All animals over 12 months of age and nonhomebred
animals younger than 12 months are
eligible for testing
• If these 2 herd tests are clear then the herd is
accredited as vaccinated and monitored free.
IBR Accreditation Programme
• Review and upgrade herd biosecurity programme
to meet the rules of the scheme (see rules summary
or CHeCS technical document).
• Test all animals of twelve months and older and all
non-homebred animals.
• Where all animals test negative this is a clear first
qualifying herd test.
• The second qualifying test can be carried out 1-12
months later. A clear test at that time confirms
accredited status.
• Annual testing is required to maintain accredited
status. This is done on a statistically based sample
from each group of animals over 12 months of age.
• Vaccinated animals can enter accredited herds,
contact your CHeCS provider to confirm % of herd.
Sale rules regarding IBR
As of October 2016, all heifers need to be isolated at
least seven days prior to testing clear and vaccinated
with an IBR marker vaccine, an inactivated IBR vaccine is
preferred to live vaccine.
Test positive animals should be removed and the
process repeated 14 days following removal of test
positives.
Isolation facilities as per CHeCS or own country
government approved, Defra etc.
Cattle vaccinated as young calves can still be isolated
and tested for IBR wild type after vaccination, testing
differentiates between marker vaccine and actual virus, a
booster would then be required pre-sale.
Testing timeline pre-sale as per CHeCS- less than 12
weeks.
A heifer will be classed as such until the first calf is born.
Non-marker vaccines will not be accepted.
Entries from Accredited herds need only to be
vaccinated.
All vaccination dates and the type of vaccine used need
to be clearly stated on your HHD.
We accept and understand that this will not
guarantee that cattle going through a market will
remain IBR free but it is the first step in taking the
breed ahead of the competition regarding IBR.
SIMMENTAL REVIEW 2018
www.britishsimmental.co.uk
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