Rail chaos disturbed cattle (9)
I believe the answer is:
charolais
'cattle' is the definition.
(Charolais is an example)
'rail chaos disturbed' is the wordplay.
'disturbed' is an anagram indicator.
'rail'+'chaos'='railchaos'
'railchaos' with letters rearranged gives 'CHAROLAIS'.
(Other definitions for charolais that I've seen before include "beast" , "White beef-cattle" , "Provider of beef" , "White breed of beef cattle" .)