Farming

‘False positives’ must be eliminated

Published

9 years ago

March 12, 2015

New bovine TB tests needed?: Cambridge University has recommended

A NEW study performed by researchers from Cambridge University has recommended that new tests are needed to make vaccination against bovine tuberculosis (bovine TB). The report points out that in order for vaccination to be viable, the number of false positives from these tests must be significantly reduced. The scientists have said the reduction in false positives in cattle is feasible, but that a vaccination programme would be challenging. Despite an intensive, and costly, control program in the United Kingdom, bovine TB persists. Although vaccinating cattle with the human BCG vaccine offers some protection in cattle, doing so is currently illegal within the EU, due to the vaccine’s interference with the skin test used for surveillance.

The Cambridge team worked alongside researchers at the government’s Animal & Plant Health Agency (APHA), to show the importance of specificity – the proportion of uninfected animals that test negative – to making disease control strategies work. The skin test currently in use has a very high estimated specificity of over 99.97%, which means that less than three animals in 10,000 will test falsely positive. However, the test as carried out in Great Britain is thought to have at best an 80% sensitivity – a measure of how many infected animals will correctly test positive – missing around 1 in 5 bovine TB-infected cattle. It is used to determine if animals, herds and countries are officially free of bovine TB.

Vaccinated animals that test positive have to be treated as infected animals. Under European law, if an animal tests positive, it must be slaughtered. The remaining herd is put under movement restrictions and tested repeatedly using both the skin test and post-mortem examinations until it can be shown to be officially clear of infection. Researchers said the duration of movement restrictions is important due to the considerable economic burden they place on farms. Also, the cost to the UK government alone is estimated to amount to half a billion pounds over the last decade; this cost includes visits to farms by veterinarians, tests carried out and compensation for the slaughter of infected animals.

For vaccination to be economically viable and acceptable within the EU, the benefits of vaccination must be great enough to outweigh any increase in testing. A new generation of diagnostic tests, known as ‘Differentiate Vaccinated from Infected Animals’ (DIVA) tests, has opened up the opportunity for the use of BCG within current control programmes. The EU has recently outlined the requirements for changes in legislation to allow cattle vaccination and a recent report from its European Food Safety Authority (EFSA) emphasized the importance of demonstrating that BCG vaccine works, and that DIVA tests can be shown to perform in large-scale field trials.

However, a key factor overlooked in the EU report was that the currently viable DIVA tests have a lower specificity than tuberculin testing; this could lead to vaccinated herds being unable to escape restrictions once a single test-positive animal has been detected, as the more times the herd is tested, the more likely the test is to record a false positive. In their study, the researchers from Cambridge and APHA used herd level models to show that the level of infection can be reduced in vaccinated herds even when DIVA sensitivity is lower than tuberculin skin testing.

However, in order to see this benefit of vaccination over 99.85% of uninfected animals will need to test negative in the DIVA test. This improved accuracy will be necessary to avoid increasing the duration of breakdowns and the number of animals condemned. Using data from previous tests on cattle, the researchers said this level of ‘specificity’ is achievable, though they said there will be challenges associated with improving accuracy. The researchers said, “Currently, there is no gold standard test to diagnose TB in cattle. Cattle that test positive are slaughtered immediately and therefore have rarely developed any physical signs – in fact, only around a half of animals examined post-mortem show physical signs of infection even if they are, indeed, infected.”

Dr Andrew Conlan from the Department of Veterinary Medicine at the University of Cambridge explained “In order for vaccination to be viable, we will need a DIVA test that has extremely high specificity. If the specificity is not good enough, the test will find false positives, leading to restrictions being put in place and a significant financial burden for the farmer. “But validating a test that has a very high specificity will in itself be an enormous challenge. We would potentially need to vaccinate, test and kill a large number of animals in order to be confident the test is accurate. This would be very expensive.”

Farming

Pembrokeshire Agricultural Society in search for county’s top progressive farmers

Published

2 weeks ago

April 9, 2024

Tom Sinclair

IF you farm in Pembrokeshire and can demonstrate your farm’s use of the latest technological methods to promote progressive, sustainable agriculture then the Pembrokeshire Agricultural Society encourage you to enter the prestigious Baron de Rutzen Award.

Adam Thorne, Pembrokeshire County Show President, said, “We are looking for local Pembrokeshire farmers, under the age of 45, who can demonstrate their farm’s use of the latest technological methods to promote progressive, sustainable agriculture. They also need to show consideration for the environment and habitat sensitivity on their farm as well as present an aesthetically pleasing example of farming in the county. The competition welcomes all livestock and arable sectors to take part.”

Last year’s winners of the Award were Mark and Caroline Davies of Little Newcastle, Haverfordwest. They milk 230 pedigree Holsteins through a fully automated system. They rear their own replacements and also have a small beef enterprise. The farm is all grassland and they follow a strict reseeding and liming policy to optimise the yield from their multi-cut silage system. The couple place significant emphasis on animal health, husbandry and breeding to maximise the efficiency of their system.

Baron John Fredrick De Rutzen was President of Pembrokeshire Agricultural Society in 1936 and the Baron de Rutzen Trophy was produced in his memory. The third Baron served in the Welsh Guards and tragically died, aged 36, in 1944.

This year’s entrants must be fully practising farmers within the county of Pembrokeshire and were under the age of 45 years on 1 January 2024. Entries can either be by nomination or direct application online on the Pembrokeshire Agricultural Society website. Click here to apply: Baron de Rutzen Award | Pembrokeshire County Show | Pembs Agricultural Society (pembsshow.org)

The closing date for nominations and applications is at noon on Wednesday, 29 May 2024.

Farming

Pembrokeshire Agricultural Society elect new president

Published

3 weeks ago

April 1, 2024

Tom Sinclair

ARABLE and beef farmer, Adam Thorne, has been unanimously elected to become the new President of Pembrokeshire Agricultural Society for the year ahead. Adam is the third generation of his family to hold the position.

During the Annual General Meeting of Pembrokeshire Agricultural Society, held last week on the Pembrokeshire Showground, Mr Tim John and his wife Margaret John were also voted in as Presidents elect.

Adam Thorne has had a long association with Pembrokeshire Agricultural Society. After visiting the show as a toddler, then helping show the family’s pedigree Herefords, his uncle got him into helping him with stewarding in his early teens. From there he progressed to being a Steward with his own section, Commercial Cattle, and then also the Butcher’s Lambs section.

From stewarding, Adam became involved with committee work, starting as an Executive and then on to the former Finance and General Purposes Committee. He has been Chairman of the Estates Committee for 12 years and is now a Board member and a Trustee.

Adam said, “I am proud of my long association with Pembrokeshire Agricultural Society. I am the third generation to now be President, following my late grandfather, Walter Thorne, my father, Robert Thorne and more recently my uncle, George Thorne. I am looking forward to my year in the prestigious position.”

Away from his work with the society, Adam runs the family’s arable and beef farm in Robeston West, Milford Haven. He has been heavily involved with Tiers Cross YFC from an early age, having been Club Secretary twice and Chairman. He has also sat on Pembrokeshire County YFC Committees and the Wales YFC Rural Affairs Committee.

The 2024 Pembrokeshire Agricultural Society officeholders, announced at the AGM, include Miss Ffion Edwards who was awarded the role of Ambassador at last year’s show. Ffion, a nurse from Maenclochog, has enjoyed many years of attending the county show and believes that there are so many good elements to it. Ffion has been a member of Llysyfran YFC for 15 years and enjoys every aspect of young farmers – trying new experiences, competing and travelling to name a few. Mrs Nicola Owen was also elected as the Honorary Treasurer.

Brian Jones, the outgoing Pembrokeshire Agricultural Society President, took the opportunity to thank everyone who had helped and supported him throughout his presidency. During his year as President, Brian and his wife Helen, raised a tremendous amount of money for various charities including the Pembrokeshire Agricultural Society, RABI, Tir Dewi and the DPJ Foundation. Brian also gave his assurances that Castell Howell will continue to sponsor the Food Hall for future years.

Pembrokeshire County Show, the largest county agricultural show in Wales, will be held over two days again this summer on 14 and 15 August. Everyone is invited to attend the celebration of rural life in the county.

Pictured (left to right): Ffion Edwards the Ambassador for 2024; Adam Thorne, President; Margaret and Tim John, the Presidents Elect.

Farming

£1,000 bursary award available to Pembrokeshire agricultural students

Published

1 month ago

March 14, 2024

Tom Sinclair

PEMBROKESHIRE Agricultural Society’s £1,000 Bursary Award is now open for applications from students studying agriculture, veterinary science, agricultural engineering, food technology, forestry or other subjects allied to agriculture.

The Student Bursary Award 2024 is available to students, from Pembrokeshire, who are currently studying or have been accepted to start their studies. They can apply for this financial support to assist with their chosen college or career path.

Last year’s winner of the award was Lottie Wilson from Hayscastle. Lottie was studying agriculture at the University of Nottingham when she applied for the bursary. When she is at home she is a general dairy farm worker as well as a lambing hand and a calving beef herd assistant. In 2021 she was the top agriculture student at Hartpury College.

Robert James, Chairman of the Society’s Bursary Committee said, “I would urge all Pembrokeshire students who study subjects that are clearly aligned to agriculture to apply for this bursary as it won’t only assist with your studies but will also give you great experiences such as undertaking an interview which is a key employment skill. It will also assist in your future career within the agriculture industry.”

“A panel of independent judges will draw up a short list of candidates who will be interviewed and the winning candidate will be asked to give a short presentation at a future meeting of the society’s show council.

“The standard of applications has always been exceptional which gives a lot of heart that there are a lot of very talented young people in our community. We are very much looking forward to receiving applications for this year’s bursary and hearing from the younger generation.”

Qualifying students must not have won the student bursary on a previous occasion, the applicant must be studying or has been accepted to study agriculture or allied subjects at a UK college or university at A-Level or higher and the applicant’s family home must be in Pembrokeshire.

The bursary is tax free and will be awarded to the student who, in the opinion of the panel of judges, has submitted the best dissertation on how the bursary will assist them to complete their course of study.

Further details and the entry form can be found online: Student Bursary Award | Pembrokeshire County Show | Pembs Agricultural Society (pembsshow.org) or by calling the show office: 01437 764331. The closing date for applications is noon on Monday, 1 July 2024.