Where one might find better sheep -- some pens (5)
I believe the answer is:
epsom
'where one might find better' is the definition.
(people bet on horse races at Epsom race course)
'sheep some pens' is the wordplay.
'pens' indicates a hidden word (pen can mean to contain or cage).
'EPSOM' can be found hidden inside 'sheep some'.
(Other definitions for epsom that I've seen before include "Poems about English racing venue" , "place for racing" , "Poems about the race-course" , "Surrey race course" , "The Oaks and Derby are run here" .)