A very good thing to have for a static pasture, is a solid perimeter fence..
Now in some instances it's not 100% required. But if you're thinking about the possibility of having more than one enterprise, it's probably a good idea.
As long as you keep a close eye (and string trimmer) on the Electric fence (if that's you're only fence), you should be fine. However it doesn't hurt anything to have a solid post and 4' high woven wire fence around your entire pasture. Albeit lot's of labor, and a very large expense. It'll serve its purpose and make your money back eventually from the product you are trying to grow/raise.
"Good Fences make good neighbors." ...especially if you're raising livestock!
This photo was taken a few years ago of our two wonderful dairy goats
