Ponies are very smart critters. If our creek overflowed and washed the fence out, it was our ponies who lead the cows, sheep and hogs out the missing fence gap. Usually the ponies would herd all the animals back down our lane to our house so we would know they were all enjoying their "freedom" break. I have seen my riding mare let a calf nurse; then nurse the sheltand mare who was suffering from too much milk in her udder because her colt was being weaned from her. And seen a pig stealing a "nursing" from a newly fresh cow who had just calved.
If there are 4 strands of barb wire on the fence post, it is probably holding in only cattle. If it has five or more strands of barb wire, it is holding in sheep and /or hogs as well. Hogs must be "rung" or will root up ground, fence, & gates. (rung= A ring in their noses). The horse does not "see" the wire (barbed) unless it has flags or similar things tied to the wire. They can come at a full run, charging blindly right through the wire, and become seriously hurt. Yes, when the barb wire snaps off the post where it was tightly strung, its a wild wire that wraps around whatever is handy. It hurts.
Most farmers and ranchers build "corrals" or padlocks for ponies & horses out of young tree trunks or wooden boards. We tied young tree saplings, about 3-4 inch-trunks, together to make our "corral", so the ponies were quickly available to ride throughout the day. With or without bridle & saddle because they were well broken to guide with a single rope from the halters or knee pressure on the sides of the ponies or horses. We often played "leap frog" onto their backs out in the pasture. And did so with a couple of cows that let us ride them. Childhood memories is one reason why I wanted to do the "pony quilt" and pass the stories along to grandson. Thanks for listening to my stories.