I endorse the plea - do not leave control of foxes to farmers!! Please!! As a farmer myself I am not good at killing things - I just about manage to poison the rats! I know of one farmer, years ago, who in desperation at the loss of his chickens, dowsed a dead one on Gramoxone (Paraquat) and left it for the fox to eat - what a bloody awful death for the fox!! But easy for the farmer.
.. I know the hunt round here is very professional when it comes to the kill and of course it is usually the older foxes that get caught first which is the right ones to cull.
It is done in season as opposed to poachers who do not respect the breeding season, they provide an excellent service with fallen stock (for me) ....