By law an entire bull (a bull that hasn’t been castrated)is not allowed to graze on land with a PROW on it
Not quite – just some breeds
This from the HSE goes to a fact sheet and…
This from naturenet
If there’s a bull in a field, watch out. In fact, if there’s any animal in a field, be careful, as even common cattle can cause serious injury or death if they get going. Dogs, especially, can be problematic, so take care when near farm animals with your dog or without. However, the law also has a few things to say about animals in such situations, and this page will explain some of them.
Occupiers may not, subject to certain important exceptions, keep bulls in fields crossed by public rights of way. The exceptions are bulls not more than 10 months old, or bulls which are not of a recognised dairy breed (currently defined as Ayrshire, British Friesian, British Holstein, Dairy Shorthorn, Guernsey, Jersey and Kerry) and are accompanied by cows and heifers. In practice, it may be difficult for a user to know whether bulls will be likely to be dangerous or not, and farmers are asked, wherever possible, not to keep any bulls in fields crossed by rights of way. Sometimes, temporary electric fencing (suitably insulated at public crossing points) can segregate the public from the bulls. Such fencing would normally require authorisation from the local Highway Authority.