Standard — cattle (5)
I believe the answer is:
stock
This clue is a double definition.
'standard' is the first definition.
(synonyms)
'cattle' is the second definition.
(I've seen this before)
(Other definitions for stock that I've seen before include "soup ingredient" , "Goods in store" , "Consomm-like liquid" , "Supply; plant" , "Cattle" .)