Draught animals (4)
I believe the answer is:
oxen
'draught animals' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for oxen that I've seen before include "Bovine creatures" , "Bovine animals, in yoke" , "(E.g. draught) cattle" , "strong animals" , "Cows and bulls" .)