I used some around my waterer and in my corral. I think it is too expensive for long stretches but works great in high pressure areas especially where you want to limit sight outside like in a corral. Railroad ties make good posts for guard rail in these type areas. I have also used telephone pole sections. Using guardrail is MUCH easier if you get the posts in the right spots to line up with the prepunched standard 6'-3" spaced holes in the guardrail and are near the correct height

I started with treated pine on 8ft centers then switched to guardrail around my waterer. Would have been much easier and neater to start with guardrail in mind. Good luck.

Jim at Dawn

The guard rail is prepunched for 3/4" fasteners. I used a 1/2" ships auger, and galvanized flat washers and 1/2" galvanized (don't use just plated) carriage bolts. There is "real" guard rail then there is what seems to be imported much lighter weight, poorly galvanized "imitation"  guard rail much cheaper. My suggestion is if you are going to do it get the real thing.