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Lesley Griffiths, Cabinet Secretary for Environment and Rural Affairs

First published:
16 January 2017
Last updated:

This was published under the 2016 to 2021 administration of the Welsh Government

Today I am publishing a report on the impact of the increased use of gamma testing on the number of cattle slaughtered because of bovine TB. The disease has a significant financial and social impact on farm businesses and the wider rural economy, which is why we established the TB eradication programme. Over the last few years we have seen good progress towards achieving our goal to eradicate bovine TB, with the number of new incidents falling by 47% to date since the high-point in 2009 and we continue to see a decrease in the proportion of herds with TB. Between 2009 and 2015, there was also a 31% fall in the number of cattle slaughtered, though subsequently, the trend turned upwards despite new incidents continuing to fall. This divergence is unusual, as the trend in animals slaughtered has tended to follow the trend in new incidents, however, it does not mean the disease is on the rise.

The rise in cattle slaughtered is primarily a result of our increased use of the interferon-gamma test. Gamma-testing has a high level of sensitivity which discloses more reactors than the standard skin test. It is one of our most important tools in eliminating disease from infected herds because, when used alongside the skin test, it improves the likelihood  infected cattle will be identified. It may also detect infection even earlier which helps us identify infected cattle before they go on to infect others. The increase in gamma-testing has resulted in a dramatic increase in the number of gamma positives, contributing significantly to the overall rise in animals slaughtered. The report explores this in more detail and describes the contributions of our strategic use of gamma to help clear infection in persistent breakdown herds and to prevent the disease from becoming established in low incidence areas.

It is my aim to keep the number of cattle slaughtered because of TB to the minimum necessary, whilst eliminating disease from herds as quickly as possible to prevent it spreading to other cattle, wildlife or humans. The measures applied to date are demonstrating a positive effect. We will continue to use the gamma test strategically where we can make the best use of it to complement our other controls. The disease picture is a complex one and our TB dashboard presents a suite of key measures in an accessible and visual way. The latest version, which has been re-designed to include interactive navigation features and more regional analysis, is available on our website at:

and the report on the impact of gamma testing is at: