.... for pasture ....
First thing I would do is talk with your agricultural agent and find out what type of grass (warm & cool season grasses) do well in your location. Ask the agent what he/she knows about "endophyte free" grass. (Hopefully your agent will know more than ours did awhile back.) It may be that the grasses you have would work well "if mowed in milk stage" and "not" permitted to mature. (Just know it is always easier to maintain a pasture with local grass than it is to maintain one with foreign grass.)
Next thing I would do is take samples of the soil to the agricultural department to discover what it needed, especially what the ph lvl is. (We had to add agricultural lime as well as quite a bit of fertilizer prior to planting grass as nothing had been on this "sandy loam" except forestry.)
I cannot find the address for what we used here; but the link is on my site at
http://motdaugrnds.250free.com/homestead/ (You can also see what a nice stand we got from that New Zealand grass.)
Remember, goats are "browsers"; not "grazers"; thus, it is good to add bushes and various vegetation they enjoy. We planted over a thousand trip-color lespedeza shrubs that are healthy and our goats love. Each winter we throw some bean seeds over the pastures too.
Creating a "browsing" pasture is a lot of fun, keeping it is a lot of work (unless you fence in small areas like we did); however, it is well worth it.
Good luck with yours.
.... as to dogs useful in protecting goats ....
All dogs need some training, especially around baby goats. We have trained 3 dogs (full-blood German Shepherd; full-blood Chocolate Lab; mutt mixed with lab, shepherd, chow, wolf). Best we ever had was the mutt! Without her help, training the other 2 would have been more difficult. However, there are hunting dogs all around us and not one ever comes onto our place!