Double fence - so we run a line of electric fence a few feet inside the boundary fence. We waste grazing. It develops into a mess of nettles because it's not getting eaten down. And people throw their apples, carrots and other crap over it anyway. Keep them in fields that don't back on to footpaths or residential areas... well wouldn't that be a luxury? Where are all these fields away from civilisation? My herd get fed over a fence that isn't in a residential area or backing on to a footpath by the way. We should make our fields and paddocks inaccessible to walkers. How exactly?
Not ideal I know, but a double fence deters at least some people. I’ve seen fields with very high boundary fences then a tall hedge as the outer fence, so you can’t touch the horses or get close (I know people can throw food in but they rarely do it if they can’t touch the horses or see them eat, and they may not even realise horses are in there).
Generally the desire to feed horses seems to come from people wanting to pet them and ‘befriend’ them or get their kids doing the same, so if the horses are out of reach/sight that makes the field much safer. I know it’s a pain to lose some grazing land to a double fence but better than random people feeding them. It’s as if people see them and think ‘ooh furry horsies to stroke and feed’ and don’t stop to think they actually belong to someone as they’re alone in a country field. Or people stop to admire them, horses come rushing up to the fence for food/attention, so next time they come armed with carrots and bring kids etc to look at them.
The type of electric outer fence with several wires so it’s hard/impossible for people to squeeze through?
Inner fence you could have solid panels at the bottom and close knit bars between the poles to stop people putting hands or food through, and to stop horses trying to get at the nettles/weeds etc.
CCTV and signs up warning people it’s private property with CCTV? Why are they trespassing over your land if there’s no footpath? Can you not secure the gates so they can’t access it? ‘Beware of guard dog’ signs, ‘these horses bite’ signs etc. Not failsafe but all good deterants.
Choosing fields on farms or livery yards that have no public rights of way through them. Unless you’re in the middle of a city they’re not too difficult to find IME.