Breed of cattle and Channel Island (8)
I believe the answer is:
guernsey
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">breed of cattle and channel island</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for guernsey that I've seen before include "Lyric poem" , "Breed of cattle and a Channel Island" , "Second largest of Channel Islands" , "Second-largest Channel Island" , "One of the Channel Islands" .)