Since I'm from the States, our laws are a bit different here, but still...

Country folks here have what they call the Three "S" solution to problems like yours - where there is a predator that is protected, but attacking/eating their livestock. At the risk of offending someone, I'll offer it anyway and hope the advice is taken in the spirit in which is given, that of someone who has been through something similar and was at the end of her rope.
The Three "S" solution stands for Shoot, Shovel, and Shut up. This was told to me by an Animal Control officer who I'd contacted about our ducks being attacked, as he tersely put it, these laws are all well and good if you're sitting behind a desk in the Capitol, but not so good if you're trying to keep your animals alive. It sounds like you're quite close to your neighbors, so perhaps Trap, Shovel and Shut up would be more appropriate. Harsh, but once the fox know where dinner is, they'll be back until you've none left at all. The only time I would not use this would be if the animal doing the killing was truly endangered, but thankfully, we've had no Bald Eagles try to take off with our birds.
I'm loathe to take the life of anything, even my broiler chickens I raise for meat, but when it comes to my poultry, I've no compunction at all about taking out something that is intent on killing everything I own and hold dear. Having lived out in the country for 25 years now, I've learned the real law of the land is kill or be killed - you can't reason with a fox (or in our case, owl)