Little swine's extreme racket (6)
I believe the answer is:
farrow
'little swine's' is the definition.
(farrow can mean a litter of pigs)
'extreme racket' is the wordplay.
'extreme' becomes 'far' (I've seen this in another clue).
'racket' becomes 'row' (both can mean a noisy disturbance).
'far'+'row'='FARROW'
(Other definitions for farrow that I've seen before include "Give birth to piglets" , "pig production" , "Produce piglets" , "Litter - very much on bank?" , "Little piggies" .)