Tissue tagging top tips for BVD control

Eradicating Bovine Viral Diarrhoea (BVD) from your herd and staying clear of it means healthier and more productive stock, less hassle for you and your staff plus financial benefits.

The cost to the national herd could be as high as £61m¹. The benefits have been estimated at £44² per cow along with reduced antibiotic usage in young stock and improved herd fertility.

BVD attacks immune systems and in young stock pneumonia, diarrhoea and fatality can occur. In adult cattle, reduced milk yield, lameness, mastitis and a host of reproductive issues are seen.

Overall, poor treatment outcomes and herd health is observed.

© 2020 by Datamars Agri UK Ltd

Managing a healthy herd is better for everyone and being BVD free lets you farm and not fight health and breeding issues.

Tag & Test is relatively hassle free and cost effective adding real value to your own stock by demonstrating they are BVD free if you sell as calves, stores and as bulling heifers.

Tag & Test as the herd calves is popular essentially gaining two tests for one as the status of the dam is also revealed too. You have to tag all youngstock anyway.

Tag & Test all calves dead or alive ASAP no later than seven days. Early testing reduces a calf becoming transiently infected (TI) and giving a positive virus result, even though they are not persistently infected (a TI should recover unlike a PI).

Avoiding TI’s lessens re-testing. Matching a calf correctly to its dam is essential so using and reading EID tags can help considerably.

Samples should be returned to the laboratory of choice ASAP, so any PI’s can be eliminated.

Carry out all necessary follow up testing following the discovery of a PI animal -speak to your vet. This is necessary to identify and remove all PI’s from your herd quickly.

You can also use a Tissue Sample Only (TSO) which works the same way a ‘third test tag’ but only takes a tissue sample notch and leaves no additional tag in. Good for retrospective testing of non-calving followers or new arrivals whose PI status is unknown.

To successfully tissue tag – factors to consider include;

• Sufficient ear tissue needs to be captured so a good molecular DNA weight can be extracted
• A tissue preservation method with sufficient desiccant present in the sample vial prevents sample putrefaction and a lower test success rate. Non desiccant tags require refrigeration
• On farm, a simple, tamper free, single step tag and test process in the shed is preferable with sample vials sealed before and after tagging to prevent contamination and lessen no-test results returning from the lab
• Certain makes of sample vial are more easily identified and retrievable if they go to ground often in straw bedded areas where animals are located
• Animals should always be suitably restrained with tags, applicators and hands clean to lessen infection and cross-contamination risk -this process is also slightly more complicated than simply applying ear tags only with more application pressure needed.

BVD Test results can be uploaded to the www.BVDFree.org.uk database in England and Wales after a farmer has registered. Separate schemes are running for Northern Ireland and Scotland.

Persistently Infected (PI) animals have BVD for life and many die but a few survive and always produce PI offspring thereafter so need to be identified and culled.  

Transiently Infected (TI) animals are non-PIs exposed to the BVD virus, exhibiting a wide range of clinical signs or none at all. If tested after they have recovered, they will show previous BVD exposure with antibodies present but not the BVD virus.

They can remain in the herd and are not a source of infection unlike a PI.

Vaccination plays a part in BVD eradication alongside tagging and testing and PI removal but cannot treat or cure PI’s. Ensure breeding cattle are vaccinated prior to bulling for coverage in the first 120 days of pregnancy preventing new PI’s.

If a herd is BVD free, a biosecurity programme along with vaccination of your breeding stock prevents BVD re-entering and/or new PI’s being born.

Treat anything that arrives onto the farm as a potential BVD carrier (including your own stock returning onto farm). BVD can cross boundaries easily by nose to nose contact. Consider double fencing or work with neighbours too.

Another popular use of tissue tagging is DNA sampling which is an increasingly important livestock management tool. Often used in the past to simply determine parentage, this technology is now enhancing herd and flock productivity and health.

Z Tag tissue sample tag is part of the new generation Datamars Z Tag range. A tissue sampling tag providing a convenient one-step sample collection for BVD eradication or DNA collection and contains desiccant preservative.

The Z Tag Tissue sampling range also offers a tissue sample only (TSO) option where no tag remains in the animal and ideal for retrospective testing where an additional tag is not required or desirable.

Available from your local UK stockist. More information and a store locator is available online at www.datamars.co.uk or call Datamars on 028 2076 8696.   

[1] Bennett and Ijpelaar, 2005

[2] Kath Aplin, veterinary adviser Boehringer Ingelheim