A research project undertaken to determine the level of close range contact between badgers and cattle at pasture in Northern Ireland has found “little evidence” the species interact with each other directly.
Northern Ireland’s Department of Agriculture and Rural Development commissioned the study to quantify the importance of direct, close-range contact between badgers and cattle at pasture to assess whether it is an important route for bovine tuberculosis transmission.
Declan O’Mahony of the Agri-Food and Biosciences Institute, who led the study, said: “There are many potential routes for the transmission of bovine tuberculosis between species that include direct close range contact between cattle and badgers or indirect contact at setts, latrines, water troughs or in farmyards.
“We need quantifiable data from scientific research on which routes are most important so that we can develop mitigation strategies that minimise the potential for disease spread between badgers and cattle. This could in turn lead to healthier badger and cattle populations.”
Bovine tuberculosis is primarily a respiratory infection and the most direct means of transfer between animals is through aerosol inhalation of bacilli from infected individuals, which can happen if an infected animal coughs or sneezes within a short distance (such as two metres) of another animal.
Using proximity collars to record interactions between animals, Dr O’Mahony and his team aimed to determine the amount of close-range (less than 2m) contact between the two species in a 1,350 hectare study area in County Down over a five month period. In total, more than 376,000 interactions were recorded – the majority of which were contacts between cattle.
Dr O’Mahony explained: “The study found that all collared cattle interacted with each other within the different herds studied and also that all collared badgers interacted with each other in their different social groups”.
However, at no time were badgers and cattle recorded as coming within direct close-range contact (< 2m) with each other during the study.
“While this might seem to be an unlikely result, it is supported by an increasing body of evidence that suggests close-range contact between badgers and cattle may not be a common occurrence,” said Dr O’Mahony.
While direct interactions between cattle and badgers were not recorded in this study, it does not necessarily mean that interactions do not occur, claimed Dr O’Mahony. However, it does support increasing evidence that such contact is likely to be at a very low level, but still may be important if infected animals are involved.