We don't have a bull but two neighbours do, plus loads of sheep, dogs etc. We double fenced the whole holding - normal sheep mesh and stobs, about 2 - 3 metres apart, with a mixed native hedgerow planted in the gap. Yes it cost and yes it took a few years to complete, but as well as stopping jumpers (no-one has jumped either in or out since the barrier went up) we also have bio-security in the event of another major disease such as F&M (no nose-touching through the march fence). It doesn't keep foxes out though
The hedgerow also provides a windbreak effect with shelter for livestock, and a wildlife corridor, with food, nesting sites and insect refuge to help birds, insects and small mammals. For us, as well as peace of mind, there's wild fruit to collect and we have now developed our own slightly warmer, calmer micro-climate.