Mae’r Treialon Difa Moch Daear yn Lloegr wedi dangos gostyngiad o 16% yn nifer yr achosion newydd o TB Gwartheg dros naw mlynedd.  Yng Nghymru, mae nifer yr achosion newydd wedi cwympo 47% mewn wyth mlynedd trwy raglen o gynnal profion amlach, gwella bioddiogelwch a mesurau eraill ar reoli gwartheg.  Fodd bynnag, rhaid cydnabod mewn buchesi lle ceir achosion tymor hir o TB bod y dystiolaeth yn awgrymu bod bywyd gwyllt yn gronfa i’r haint.
The Randomised Badger Culling Trial in England showed a net reduction of 16% of new incidents of bovine TB over nine years. In Wales, the number of new incidents recorded has reduced by 47% in eight years through application of increased testing frequency, improved biosecurity and other cattle control measures alone. However, it is recognised that in a number of long term TB breakdowns the disease picture points towards a wildlife reservoir of infection.