Plow-pulling animals (4)
I believe the answer is:
oxen
'plow-pulling animals' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for oxen that I've seen before include "Heavy cattle" , "Horned farm animals" , "(E.g. draught) cattle" , "Large bovine animals" , "Lowers" .)