My Bluefaced Leicesters (BFLs) are currently in two pens that share a section of fence. Each pen has a ram and 3-4 ewes. The pen has 4x4 treated posts sunk into the ground as deep as I could dig before I hit a boulder (generally 18-30 inches - New Hampshire is the "granite state" and the glaciers dropped rocks everywhere). The posts are connected by horizontal 2x4s at 6" and 48" above the ground. I stapled 47" woven wire sheep fencing to whole thing. This wire is heavy, sturdy and a pain to work with. But it is strong and I figured there was no way any sheep was going to get out, and no canine was going to get in - if there was going to be a problem, it was going to be something jumping over. My sheep can easily clear a 42" fence when they want to. And snow buildup makes the fence shorter every storm (got another 4" today).
It turns out I had it all wrong.
A couple of weeks ago, I noticed the fence was dented and deformed between the pens. Today I noticed one of the rams was kinda bloody around his neck and shoulder. I couldn't catch him, so I am not sure where exactly he got cut, but he seems to be ok. While I was trying to corner him, I noticed that the woven wire fence between the pens is broken in multiple places and bent all out of shape. The holes are big enough that one of the yearlying ewes could squeeze through if she wanted to. Fortunately, everyone was still in the right pen.
I still cannot believe that they managed to do this much damage to the fence "bare handed." I know I couldn't have done it without my bolt cutters.
Lesson: Don't underestimate the strength of a motivated ram.
I had some steel panels in the barn, and reinforced the fence that divides the pen. Hopefully that will convince them to stay in their own pens.