Good points all thanks - I was thinking I might avoid a little work putting in strainers when trees in a good position but it looks as if it will be worth it to put the posts in - proportionate to the whole job it is not much different. (It seems to me likely that both tree and fence will outlive us but not good to pass on a problem to future generations!) Electric through the woodland section might be a thought as if the animals got through it would still leave them on our land. On the other area I was thinking of I want to have electric backed by stock fencing as this is where I hope to put pigs and is a place where escape from the enclosure could result in getting out of our land.
Thank you
Simon