Brought up food, we hear (4)
I believe the answer is:
'brought up' is the definition.
(to breed is to bring up or raise)
'food we hear' is the wordplay.
'food' becomes 'bread' (bread is a kind of food).
'we hear' indicates a 'sounds like' (homophone) clue.
'bread' sounds like 'BRED'.
(Other definitions for bred that I've seen before include "Gave rise to" , "Had children" , "Propagated, raised" , "Multiplied" , "Very (music)" .)