Loaf of bread for horse (3)
I believe the answer is:
cob
This clue is a triple definition!
'loaf' is the first definition.
(I've seen this before)
'of' acts as a link.
'bread' is the second definition.
(I've seen this before)
'for horse' is the third definition.
(type of horse)
(Other definitions for cob that I've seen before include "mount" , "mixture of clay and straw" , "Round loaf of bread" , "Swan of Jacobean origin" , "Hazelnut" .)