Advice on other Bovine Tuberculosis (TB) controls

This page provides advice and guidance on other control measures in relation to Bovine Tuberculosis (TB)

Association of herd numbers

In Northern Ireland, there are occasions when herds are managed together, such as within families, winter housing, etc.

The Tuberculosis (TB) Control Order (NI) 1999 defines a herd as “a group of animals kept, managed or housed together, on a holding in such manner and under such conditions as will in the opinion of a veterinary inspector minimise the possibility of infection to any other animals whether kept on the same holding or another holding”.

For disease control and prevention purposes the group of cattle that must be considered is the herd. The legal definition permits a herd to consist of cattle from one or more herd numbers.

For administrative purposes Veterinary Service links the different herd numbers that constitute a herd, by associating those herd numbers.
Establishing which groups of associated herd numbers constitute herds aids the control and prevention of disease such as TB and Foot & Mouth.

What happens when an animal is moved from a TB-restricted herd into a herd that is free of tuberculosis?

If an animal moves out of a TB-restricted herd into a TB-free herd, the receiving herd will be placed under movement restriction (ie no moves out except to slaughter). One example of this would be where a herd has not completed an Annual Herd Test in time, has been placed under BT25 restriction pending completion of the test and has moved cattle in contravention of the BT25 notice. The minimum requirement before restrictions will be lifted is that the moved-in animal is tested clear. This could be done either by an individual animal test or at your routine herd test.  The individual animal test may have to be paid for by the current owner of the animal.

What calves need TB tested?

All animals except those that are less than 6 weeks old and are in their natal herd (birth herd) are required to be TB tested during herd tests. All animals of all ages must be tested in reactor herd tests (RHT/RH1/RH2).

Can my Annual Herd Test be used as a pre-export test?

Export to the EU:

Yes. Herd keepers can use Annual Herd Test results (or the results from any other routine herd test) as long as it’s a clear herd test. Please note that the test results are interpreted differently for EU export, ie your herd may have a clear herd test but not all animals may be eligible for export. Animal test information will be available from your local DVO and available to your veterinary practice on e-PVP.

All breeding and production animals 42 days of age or older at the time of export must complete a TB test within the 30 days prior to export. The bovine result must not have a rise of more than 2 mm.

Export to GB:

Yes. For movements to GB, TB test results are interpreted in the same way as for any routine test in Northern Ireland.

What will happen if I have an inconclusive animal in my herd?

Where an inconclusive TB animal is detected and there has been an OTW TB breakdown within the preceding 3 years, ALL movements out of the herd are restricted until the inconclusive animal is retested.

What is an OTW TB breakdown?

An OTW (Officially TB free status Withdrawn) breakdown is one where any animal has had two positive results from the four possible tests for TB (skin, post mortem, histology, bacteriology), or where there were more than 5 positive animals during the course of a breakdown.

What if I have an inconclusive animal and have not had an OTW TB breakdown in the preceding 3 years?

Where an inconclusive animal is detected and there is no history of TB in the herd, or even if there has been an OTS breakdown, in the preceding 3 years, the other animals in the herd may move within the UK but cannot go for intra-community trade. The inconclusive animal cannot be sold live.

What is an OTS TB breakdown?

An OTS (Officially TB free status Suspended) breakdown is one where any animal has had a TB positive result at the skin test or at post mortem, and there has only been one reactor during the course of the breakdown (or less than five animals with lesions at routine slaughter). If TB is confirmed, the breakdown will become OTW (Officially TB free status Withdrawn). Confirmation requires two positive test results for an animal out of four possible tests (eg skin, post-mortem, histology, bacteriology). 

What is NEX status?

When an animal becomes inconclusive in a herd, NEX status is applied to all animals in that herd and will remain on any animals that subsequently leave that herd. NEX will be removed only when the herd with the inconclusive animal has its TB restriction lifted. This will happen if the retest of the inconclusive gives a negative result, or if a whole herd test is negative.
NEX is an individual animal status that means an animal cannot enter intracommunity trade but can go for local and GB trade. NEX cannot be removed by a clear test on the animal with NEX status.

How will I know the status of individual animals in my herd at any one time?

Information on the status of individual animals is available from APHIS-On-Line on the DAERA Rural Portal or on your herd list which is available from your local DVO.

What happens if my inconclusive animal becomes a TB reactor?

Your herd will become a TB breakdown herd. If TB is confirmed, animals that moved out before the breakdown will be restricted and tested.

If I buy an animal from an inconclusive restricted herd and that animal goes clear in a TB test in my herd, can I then export it for intra-community trade?

No. The NEX restriction on the animal remains until the inconclusive in the original herd is resolved, despite the animal that you have bought testing clear. Your animal is permitted to go for trade within NI or GB while it has the NEX restriction. It cannot move outside the UK.

What do OTF, OTS and OTW statuses mean?

OTF

OTF means Officially Tuberculosis Free and is used in EU Directive 64/432 to describe those cattle herds that may undertake intra-community trade.
A herd is OTF if:

New herd

All the animals within the herd originate from OTF herds, or,
All have undergone a TB test with negative results 60 days after the establishment of the herd.

Existing herd

All animals undergo a TB test with negative results annually, and,
There are no clinical signs or suspicion of TB infection in the herd.

OTS

OTS means OTF Suspended. The breakdown herd status is OTS if:

  • there is a total of 1 reactor or 1-5 LRSs (lesion at routine slaughter animals) during the course of the breakdown, and
  • no animal has had two positive results from the four possible tests (skin, post mortem, histology, bacteriology)

The herd remains OTS only if the patch Veterinary Officer (VO) is content that the disease risk is not high enough to require OTW.

A herd will also be made OTS if there is a suspect clinical case.

An OTS breakdown herd is prohibited from moving animals into another herd, market or export. Animals may move direct to slaughter. An OTS breakdown herd can usually purchase animals from OTF herds.

OTW

OTW means OTF Withdrawn. The breakdown herd status is OTW if:

  • there is a total of more than 1 reactor / 5 LRSs (lesion at routine slaughter animals) during the course of the breakdown, or
  • any animal has had two positive results from the four possible tests (skin, post mortem, histology, bacteriology), or
  • any animal has had positive bacteriology results for bovine TB, or
  • the VO decides that the level of disease risk requires OTW.

An OTW breakdown herd is prohibited from moving animals into another herd, to market or export. Animals may move direct to slaughter. An OTW breakdown herd can usually purchase animals from OTF herds. However, moves into an OTW breakdown herd may be prohibited should the VO consider it necessary due to the severity of the breakdown.

Any associated herds will always have the same herd status (OTS, OTW) as the breakdown herd.

What testing is required if my herd is OTS or OTW?

An OTS herd requires:

An immediate stabilising herd test, RHT, is required if the TB breakdown began with a single animal test (skin test or lesion at routine slaughter). This may sometimes be a part test for the most at risk group, eg a test for the group from which the reactor animal came.

One clear herd test, RH1 (always a full herd test).

Cleansing and disinfection completed and inspected.

An OTW herd requires:

An immediate stabilising herd test, RHT, is required if the TB breakdown began with a single animal test (skin test or lesion at routine slaughter). This may sometimes be a part test for the most at risk group, eg a test for the group from which the reactor animal came.

Two clear herd tests, RH1 and RH2 (always full herd tests).

All herd tests will be interpreted under severe interpretation.
Cleansing and disinfection completed and inspected.

What is the timing of these tests?

The minimum test intervals are:

60 days:

Between the isolation of an animal positive at a single animal test and RH1

Between a positive RHT and RH1

Between RH1 and RH2

42 days:

Between a negative RHT and RH1

How long does it take for abattoir and laboratory test results?

Post mortem:

Results available within 1-2 days of slaughter.

Histology:

Results available within 2 weeks of laboratory receiving sample from post mortem.

Bacteriology:

Result available usually 8-10 weeks after laboratory receives sample from post mortem. If positive, some results may be available as early as 5 weeks.

Back to top