BVD eradication scheme phase 5 - December 2019: guidance

4. BVD Mandatory Screening

Testing options

Permitted screening tests for breeding herds that are BVD Negative or have been BVD Not Negative for less than 15 months:

Antibody: Tests for exposure to the virus.

Vaccination can affect the antibody result of a check test as vaccinated animals are likely to give a positive result. This would result in a BVD Not Negative herd status. Discuss BVD vaccination with your vet when deciding which animals to sample for the check test.

Antigen/Virus: Tests for the presence of virus.

Cattle keepers are recommended to get veterinary advice on the most appropriate screening test for their herds.

The following should be considered when choosing a screening test:

• size of herd
• calving pattern
• vaccine use
• age of animals
• separate management groups

A "separately managed group" is a group of animals that have been housed or grazed together for at least the past two months. See section 7 for more detail.

Vet online BVD training is available through SRUC. This CPD course covers specific vet instructions for BVD testing, including vaccinations, separately managed groups and other helpful information. Vets must complete this to authorise vet declarations. The course is accessed through the Scottish Government website under the Scottish BVD Eradication Scheme www.gov.scot/publications/bovine-viral-diarrhoea-bvd/pages/scottish-bvd-eradication-scheme/

Cattle keepers can take tissue samples themselves, only vets can take blood samples.

Tissue Tagging

From 1st December 2019, when the calf is tissue tagged under 20 days old an official tag must be used.

When applying tissue tags, make sure you are using the correct tagging pliers and that the pin is straight. Industry figures suggest that about 1 tag in 100 fails. If the laboratory reports that the sample tube was empty or the sample could not be tested, the animal will need to be re-sampled. Re-sampling options are:

The tissue goes into the labelled capsule when the animal is tagged, which is then snapped off and sent to the laboratory. If you want to purchase ear tissue tags, then contact your usual ear tag supplier. If they do not stock them, they will direct you to somewhere that does.

Indicate when you have tested all calves

If you choose to get your BVD herd status by testing all calves born on your holding, you must test all calves that are registered with BCMS, even if they die, as BVD could be the cause of death. You must tell the testing laboratory when you reach the end of the calving year. The submission form (sample below) should include a box to indicate that the calving year is now complete. This alerts the lab that it is time to set the annual status for the herd. Herds that calve all year round need to choose an end-of-calving date so that the herd status can be updated annually.

It is also advisable to test any animals that:

• do not produce a live calf, or
• abort a foetus, or
• die before being registered

to ensure these are not persistently infected. The same applies to barren cows.

Assumed Status - Testing a dead calf which has been registered will give the dam an assumed status. When testing an unregistered dead calf, the dam's ear tag number should be included on the submission form, so that she can be allocated an Assumed Negative status if the calf tests BVD negative.

Submission forms are available from approved laboratories, tissue tag suppliers and the website www.gov.scot/bvd. Please use an up-to-date form.