It is indeed a huge disappointment. I spoke to the professor on that very point just the other day.
The field trial I mentioned ran for seven years to 2005 and was overseen by the Independent Scientific Group on Cattle TB under the chairmanship of Professor John Bourne. The study found that reactive badger culling resulted in a significant increase in cattle TB to the extent that reactive culling was abandoned early in the trial. Proactive culling of badgers resulted in an average reduction of TB in cattle of approximately 23% in proactive culling zones compared with control areas,
but an increase of approximately 24.5% on neighbouring land not subject to culling, which was thought to be due to the perturbing impact of culling.
The Independent Scientific Group on Cattle TB concluded: badger culling can make no meaningful contribution to the future control of TB in cattle; deficiencies in cattle testing regimes mean that cattle themselves contribute significantly to the persistence and spread of disease in areas where TB occurs—that is, cattle are the disease reservoir; cattle-to-cattle transmission is the main cause of disease spread to new geographic areas; substantial reductions in cattle TB incidence could be achieved by improving cattle-based control measures; and it was unfortunate that agricultural and veterinary leaders continued to believe, despite overwhelming scientific evidence to the contrary, that the main approach to cattle TB control must involve some form of badger population control. No substantial or respectable body of scientific work has ever been produced to contradict the conclusions of the Independent Scientific Group on Cattle TB.
In short, scientific evidence does not identify a causal relationship between the presence of badgers and a rising incidence of bovine TB in cattle, nor do scientific data suggest that culling badgers reduces the prevalence of the disease in beef and dairy herds.