Crop farm animals initially ignored (4)
I believe the answer is:
oats
'crop' is the definition.
(type of plant)
'farm animals initially ignored' is the wordplay.
'farm animals' becomes 'goats' (goats might be kept on a farm).
'initially ignored' means to remove the first letter.
'goats' with its initial letter removed is 'OATS'.
(Other definitions for oats that I've seen before include "Young men sow wild ones" , "Porridge ingredients" , "Edible grass seeds" , "Cereal food for horses" , "Sow wild ones in disreputable youth" .)