Three research projects aimed at supporting the Department of Agriculture’s TB eradication programme were awarded a total €625,768 in funding by Minister of State Research and Development Martin Heydon this week. All involved say their work is part of a bigger picture to study the disease.

BoviTB - Bovine immune systems and TB response

An animal with a weak immune system may be more likely to contract and test positive for TB, says head of UCD Animal and Bioscience Department, Dr David Kenny.

Working with Teagasc researcher Niamh Field, Dr Kenny and team are setting out to determine if conditions which weaken the immune system such as calving, early lactation and poor herd management, can lead to a spike in the disease.

Similarly, as TB tests rely on the cow’s immune system to detect infection, the researchers will decipher the reliability of herd testing during these periods.

Dr Kenny said that the ‘BoviTB’ research team could eventually provide farmers with the scientific evidence to refuse a herd test during early lactation, something he said the Department of Agriculture has acknowledged could be justified.

Cattle may be more likely to test positive for TB in early lactation. \ Donal O'Leary.

“There’s no point in doing something if it’s the wrong time or thing to do. If you can’t get an accurate test, then there’s no point. We will need to feed this back into policy,” he said.

The UCD and Teagasc research is solely based on retrospective data – Department, ICBF and Teagasc data going back 20 years is to be examined, looking at what life stage cattle were at when they tested positive for TB.

This, Dr Kenny said, will build up a picture which could also show which types, breeds and ages of cattle have more commonly gone down with TB, suggesting that there could be certain bulls or genes which are more likely to have offspring impacted, which should be avoided.

“You could potentially end up with a trajectory that might indicate that these cattle are more likely to become TB reactors,” he said.

What will it do

Provide evidence about a potential policy recommendation that herd testing should be avoided around calving and early lactation. Give a map of the types of cattle, breeds and ages most commonly down with TB.

  • Timeline: Coming months.
  • TB bacteria genome sequencing

    Researchers at the UCD Veterinary School are working to develop efficiencies for sequencing the genome of the bacteria that causes TB, Mycobacterium bovis.

    UCD infection biology professor Stephen Gordon is leading a team which will map and track the potentially various strains of TB in cattle, badgers and deer in this way, to create a national picture.

    When an animal is culled for TB, and disease is evident in its lungs, the TB-causing bacteria can be extracted and cultured. Bacteria DNA from this culture can eventually be ‘cracked open’ and genome sequenced, getting into the weeds of exactly what type of TB it is.

    Twenty years ago, this genome sequencing cost about €1m per genome – it now costs about €100.

    Sequencing the genome of the TB-causing bacteria a farmer’s cattle go down with creates a picture which accurately allows vets to track the disease.

    The research is “another tool” which will nationally map how TB is “moving into an area and persisting”

    For example, if the reactor cattle have several different TB strains, then they contracted it from different sources.

    If the same genome was found in the deer culled in adjacent woodland, the TB likely came from those deer.

    Over time, Prof Gordon says they will be able to give timescales to the genomes and accurately establish whether it was the deer who gave it to the cattle or vice versa – essentially, who had it first.

    If cattle going down with TB in Tipperary all had one strain, unique from anywhere else, and this strain then turns up in Wexford, the scientists will be able to map it.

    Overall, the research is “another tool” which will nationally map how TB is “moving into an area and persisting,” said Prof Gordon.

    What will it do

    Determine the various strains of TB in Irish cattle.

    Track the transmission of disease.

  • Timeline: Five to 10 years.
  • DNA testing Ireland’s badgers

    We have a poor understanding of the population density and distribution of Ireland’s badgers and addressing this will aid TB eradication, says Dr Allan McDevitt of the School of Natural Resources and the Environment at Atlantic Technological University (ATU).

    Dr McDevitt and team will work with the South East Technological University (SETU) and the Department of Agriculture staff already tracking and catching badgers to collect faeces and hair samples.

    There is no accurate data on Ireland's badger population, according to researchers at Atlantic Technological University (ATU).

    In this way, the researchers will create a DNA map of Ireland’s badgers, showing their migration from one area to another and their genetic diversity.

    They will also determine the ‘families’ of badgers more resistant to TB and those more susceptible.

    “We want to bring in a DNA finger-printing kind of approach. We’ll figure out what share of the population we’re actually (TB) vaccinating,” said Dr McDevitt.

    What will it do

    Accurately determine badger population density and distribution.

    Analyse what proportion of the population is being vaccinated for TB.

  • Timeline: Coming months.
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