Smallest number of sheep covered by newspaper (6)
I believe the answer is:
fewest
'smallest number' is the definition.
(I've seen this before)
'sheep covered by newspaper' is the wordplay.
'sheep' becomes 'ewes' (I've seen this before).
'covered by' indicates putting letters inside.
'newspaper' becomes 'ft'.
'ewes' put within 'ft' is 'FEWEST'.
'of' acts as a link.
(Other definitions for fewest that I've seen before include "most opposite" , "Smallest number" , "Least abundant" , "Minimum number" , "The lowest number" .)