Domesticated bovines (4)
I believe the answer is:
oxen
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">domesticated bovines</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for oxen that I've seen before include "Bovine mammals" , "Domesticated cattle" , "workers in the field?" , "strong animals" , "Lowers" .)