It is common sense not to put an aggressive bull in a field with a public footpath, but the risk of harm extends also to horses, cows with young calves and bullocks. Essentially, all livestock is unpredictable and landowners should take this into account when deciding where to graze their stock.
If someone is injured by livestock whilst using a public footpath, the landowner may be legally liable unless they can prove that they reasonably assessed the risks before placing the livestock in the field and took adequate steps to minimise the risk.
Consider ways to reduce risk such as fencing off the footpath from your stock or corralling your stock in a safe area. Place signs on field gates and stiles to advise walkers about livestock in the field and the potential risks when walking near them. In that way, walkers can make an informed decision about whether to continue. Your signs may refer to the Countryside Code and remind walkers to keep dogs under control.
Remember to keep signs up to date. Avoid any false information that could deter walkers and breach the law - potentially a criminal offence. The HSE produce a useful information leaflet no.17 called "Cattle and Public Access in England and Wales" and Natural England produce a Land Managers' Guidance Pack with advice on signage available online or by post.
If there is any doubt about the route of a public footpath, erect signs to guide walkers along the correct path to avoid the risk that they take short cuts that might be unsafe. Your responsibility for an injury from your livestock can extend to anyone on your land even if they are trespassing.
By taking these simple steps to reduce risk, you will be improving safety and enhancing enjoyment for those who walk on your land.