Farm Ireland
Independent.ie

Tuesday 26 September 2017

Plan of attack for year two of BVD tissue tag testing

Animal Health Ireland has written to farmers whose animals are classed as persistently infected. Photo: Animal Health Ireland.
Animal Health Ireland has written to farmers whose animals are classed as persistently infected. Photo: Animal Health Ireland.

Dr David Graham

For most herds, 2014 is the second year of tissue tag testing within the national BVD eradication programme, with the majority having had an initial round of negative results in 2013.

Many herds have either already, or most certainly will shortly, begin their second round of tagging

In this article, I want to highlight some of the key points in relation to this.

Tagging of calves

Tag calves as soon as possible after birth, even if samples are only being submitted once per week. This will minimise the likelihood of initial positive results due to transient infections that are subsequently negative on retesting.

Store samples in a cool, dark place and submit to the testing laboratory within seven days of collection.

Posting samples

Place samples in a sealable bag and in a sturdy envelope. The minimum fee for submitting tags through the postal system (even for one tag) to a laboratory in the Republic of Ireland or in Northern Ireland is €1.05.

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This should be sufficient for up to 10 samples, provided they are packed flat, rather than bulked up within the envelope.

If you have more than 10 samples, it is advisable to take your package to the post office to ensure the correct postage is paid, since underpayment will lead to samples being detained by An Post.

Write your name, address and herd number on the top left-hand corner of the envelope.

Prompt receipt of results

Ensure that Animal Health Ireland has a current mobile phone number for you to provide results.

To update your contact details, call 076-106-4590 or email helpdesk@bvdfree.ie.

Positive and inconclusive tag results

You may carry out a follow-up confirmatory test (blood sample or tissue tag) three weeks after taking the first positive sample. If the status of the dam of the calf is unknown, sample her as well.

You will receive a letter giving further details on these follow-up actions and a submission form for any samples taken.

Consult your veterinary practitioner about further herd investigation to make sure that any other PI animals are identified and removed as quickly as possible.

Disposal of PIs

PI (persistently infected) animals are the most important source of infection, posing a particular threat to pregnant stock in your own and neighbouring herds, with the risk of further PI calves being born next year season.

If you have PI calves, cull these as quickly as possible and certainly before the start of the breeding season.

Failure to do so may result in additional tissue tag testing being required in your herd and increase the overall costs and duration of the national eradication programme.

In addition, PI animals are likely to fail to thrive and to die, even if apparently normal at birth.

Biosecurity

Purchased stock (including pregnant cattle that may be carrying PI calves) and contacts at boundaries are the biggest risks for introducing infection that may in turn lead to the birth of further PI calves.

Purchased animals should ideally be tested negative for BVD prior to purchase. Where pre-purchase testing is not possible, cattle should be isolated post-purchase until tested negative.

Note that pregnant non-PI cattle may carry a PI calf if they were exposed to BVD virus during early pregnancy (known as Trojan cattle).

Isolate any purchased in-calf heifers or cows until they have calved and the calf has tested negative for BVD virus.

Where possible, plan grazing of pregnant stock at home and on out-farms to minimise contact with cattle from other herds at boundaries.

For more details see www.biosecurity.ie.

Database

All of your test results and programme letters are available to you on the ICBF database.

Dr David Graham is a programme manager for Biosecure Diseases at Animal Health Ireland

Irish Independent



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