[17AndCounting]

We want to subdivide our land into smaller fields so we can rotate our stock around and separate them at times.

We have 3 fields next to each other, currently all one big space but there is a natural boundary between them made up of very mature trees and some hedgrow stuff, there's nothing young and no saplings. There are some very significant gaps hence they are able to move between the fields at present.

Would you fence around the trees on both sides (so they can't get to them) or would you include them in one of the fields? I feel that the trees provide them with some natural shelter but I'm not sure what's best to do. Because the trees/hedgerow are entirely natural fencing round them will mean losing a lot of  grazing land or we're going to have the most wibbly/wobbly looking fence if we keep to the tree line     

Taking the trees out is not an option.

If it makes any difference we have Hebrideans, Shetland, Black Welsh Mountain, Suffolk Cross, Texel and Romney as well as alpacas.

Thanks in advance for any advice.

[sh3ph3rd]

If the hedgerow and trees contain no toxic species or possibilities of entangling/inconveniently hiding lambs I'd include them in one paddock, or two (lol @ how the fence would look) for the sake of the sheep's diet (if the trees or hedgerows contain any edible species). I've not kept your breeds of sheep and don't know what species of plants you're talking about so I wouldn't know what they'd like.

If fencing around them would lose a lot of grazing land, it sounds like they might be a hindrance to lambing, if they're so dense and the ewes/lambs hide in there... Sounds like maybe fencing the trees/hedgerows out of any intended lambing paddock might make things easier on you. No idea! lol, sorry.

[Pedwardine]

I'd include if you can. Just bear in mind when the sun is at it's highest which paddock they should be in to give good shade. Likewise the prevailing winds should dictate if they would serve as an effective windbreak/protection from rain. I'd clear around and prune lower branches so as to remove the chances of lamb hiding places.

[Fleecewife]

Hebrideans and Shetlands will eat the bark and leaves of many trees and rapidly ring bark them.  So if you want to preserve the trees/hedge you will need to put up a fence on each side of the line of trees.  Remember that the sheep will stand up on their hind legs to reach over a fence to reach browsing, so leave a decent gap between the two fences.
 
I would beware of including living trees in a fence line anyway - trees grow and increase their circumference, so if there is a fence touching against the trunk it will eventually engulf the fence wire which probably isn't too good for the trees.
 
Also, sheep will clean out the bottom of a hedge by killing off the lower branches, even if they don't actually ring bark the tree, so you would no longer have such a good windbreak
 
Otherwise, yes it depends on the tree species as to whether or not it is suitable for sheep to browse.
 
Once the fences are up you can plant saplings to fill the gap.

[Marches Farmer]

Our Southdowns will ignore tree bark but the Badger Face love it, especially ash, hazel and chestnut.  We have some 300 year old oaks and younger Scots Pines that are ignored.