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Pig need training for the electric fence - otherwise they are as likely to go through as stay in. In essence when you bet them, you'd create a small fenced area say 15ft square around your ark, and run a single strand of white electric horse tape around the inside edge at about 6 inches. (Use white tape, as it is easy for them to see, and they create an association. They'll soon learn to stick away from the electric, takes maybe two days at most. Then you can have them just behind the electric.
As a first timer, I'd suggest you stick to a lop eared breed (one with ears down) as they tend to be more docile. If your two crosses are prick eared, it might be harder for you, and both the Mangalitza and Iron age tend to be for the more advanced pig keeper.
Lady K (and Sophie!) - if you have a large area to clear, then create a "radial" system, ie have the ark near the middle, and then use the electric to create an area like a slice of pie. When they have cleared that area, then move round the clock face (to mix metaphors) so they have a fresh slice. That way you don't need to move the ark.