|Departmental project code||13/3/S3 (Originally 12/3/S1)|
|Provider project code||44963|
|Project date||01 October 2013|
The potential role of cattle slurry in the spread of bovine tuberculosis
This is a DARD commissioned to examine the potential role of cattle slurry in the spread of bovine TB.
Defined key word searches were used to select relevant scientific literature using online resources (PubMed, Science Direct and Web of Science), with a preference for high-quality systematic reviews. Literature was accessed until May 2013.
Some of the key findings from the review are as follows:
- While cattle slurry may potentially present a risk in terms of spread of bovine tuberculosis, it was not possible to quantify the risk given the lack of published information in some key areas.
- Slurry containing viable M. bovis, the causative agent of bovine TB, may theoretically contaminate pasture, soil and silage resulting in transmission to cattle (and local wildlife) for a considerable length of time after the application of slurry (depending on environmental conditions).
- Spreading slurry can generate aerosols that potentially carry bacteria for considerable distances. Transmission to neighbouring farms via slurry aerosols, whilst probably unlikely, cannot currently be excluded at this time.
- The risk of bovine TB transmission via cattle slurry from reactor herds may be reduced by adopting some of the following on-farm practices:
- store cattle slurry for a minimum of six months or treat with thick lime milk before spreading to land to ensure that M. bovis is inactivated
- to minimise aerosol production during spreading, slurry should be spread in calm weather (not windy) using a downward discharge method such as band spreading or injection using attachments such as the trailing-shoe
- mixing and pumping of slurry in under floor pits should be avoided while animals are present in housing to reduce/prevent inhalation of infectious aerosols
- if slurry is to be spread on grazing pasture, land should not be grazed for at least 2 months following spreading. Alternatively, slurry should be spread on arable land either by injection or ploughing in after spreading
More project information
Lyanne McCallan, Jim McNair, Robin Skuce
- AFBI – Veterinary Sciences Division (VSD)