Witric Power - Witricity Explained

I have 2 German shepherds. I have 5 acres of country plus 200 or more acres outside of that where they can run. recently :Jack" the male likes to go and run the farmers calves in a field next to our land. He wouldn`t hurt them it`s just the fun of the chase to him. He is young and playfull but a huge dog..We had a visit from the farmer the other day telling us he would be SHOT if found over there again. Can`t blame him I guess but now we have 2 german shepherds being confined to kennels when they have been raised running free and it`s killing them. They are high energy dogs and need to run and play. We let them out to play some but Jack is kinda hard headed and still tries to run over there. I have considered shock collars (at least for the male )
Is there a shock collar available that is LONG RANGE that would cover our entire 5 acres that is wireless ? I hate to resort to shock collars but it`s better than being shot by the farmer or kenneled the rest of there lives. Witricity powered: witric power.

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