English: chronic herd breakdown 
Welsh: buches ag achosion cronig o TB 
Subject: Amaeth
Welsh definition: A ‘chronic’ herd breakdown is defined as either a herd which is OTFW and: Has been OTFW for a duration of 18 months or longer, OR Became OTFW at or before the 12M check test, following an earlier OTFW breakdown, BUT excluding those recurrent breakdowns where all reactors are animals bought in since the close of the previous incident, unless subsequent molecular typing information does not support a purchased origin.
Plural: buchesi ag achosion cronig o TB