Bovine TB Study

The results of a study into Bovine TB suggests that  larger herds, growing maize, feeding silage and fewer hedgerows on holdings have all been linked to a higher risk of the disease.  The research was carried out by the University of Exeter and analysed data from 503 farms which had suffered a TB breakdown together with 808 control farms located in high-risk TB areas. 

The study which was funded by the Biotechnology and Biological Sciences Research Council (BBSRC) found that farms with herds of 150 cattle or more were 50% more likely to suffer a Bovine TB outbreak than on farms with herds of less than 50 cattle.  It also found that for every 10 hectares of maize grown the Bovine TB risk increased by 20%; badgers are known to like maize.  Dairy and beef systems which fed silage saw the risk of Bovine TB doubling and holdings with marshland also saw an increased risk.  But for farms with more than 50km of field boundaries, for each extra km of hedgerow there was a 37% reduction in the risk of a Bovine TB breakdown.  The likely reason for this is that hedgerow rich pastures are less likely to be infected with badger urine and faeces. 

The percentage increases and decreases in the risks reported above are in isolation of each other, but Dr. Fiona Mathews, who led the study has reported that all of the effects were ‘additive’, so that changing more than one of the aspects could potentially make large changes to the risks to Bovine TB.