Caught by farm animal in crush (4)
I believe the answer is:
cram
'crush' is the definition.
(I have seen 'A crush' mean 'cram' so perhaps 'crush' could also mean 'cram')
'caught by farm animal' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'by' means one lot of letters go next to another.
'farm animal' becomes 'ram' (male sheep).
'c'+'ram'='CRAM'
'in' is the link.
(Other definitions for cram that I've seen before include "A crush" , "Press together" , "Revise hard" , "Pack in or study hard" , "prepare hastily for the paper" .)