When vinyl fence is made properly it is as strong as wood. Vinyl fence behaves differently from wood (if it breaks it usually won't leave wood-like slivers or splinters to hurt you or your animals) but it is as suitable for containing livestock as a wood fence. A horse or bull can break through a wood fence, and so can they break through a vinyl fence. The difference is that vinyl tends to result in fewer injuries to the animal. Vinyl fence can be climbed on and over similar to any other fence.