I took old telephone posts and cut them into 8' lengths, and cemented them in the ground 60' apart- putting three metal T-posts between each telephone pole (so the barbed wire is supported every 15 feet)- Stretched the wire good and tight (5 strands) and it works great on cows of all sizes and was economical to build. If I had a nasty bull though, I might worry. (If I coud've afforded to use field fence, I would have....ya can't beat it- and iffin ya ever want other types of animules- like goats or something- ya don't have to worry...it works great on just about everything...if you can afford field fence, go for it!)