The Livestock on road call could have 3 or 4 different variants
First the basic one on a country road only 1 or 2 police cars needed
Second on a busy road where the requirement includes a traffic car
Third and Forth are variants of the first two but adding firearms as occasionally they are needed, the HGV Lost load (livestock) call has firearms requirement.
There are no arrests for any of them and no chance you need fire for these calls.
These calls could also easily expand to include
Accident caused by livestock this could include a fire response with 1 fire engine and 1 rescue needed also can include the need for ambulances (easily 1 to 4 would be realistic for patients), this call could easily be scalable to include the need for more of each service and include HART too depending on vehicle(s) involved.
It could also expand into an Animal Rescue the needs a fire rescue response.
You then have scope to have the call also evolve into a ambulance call as person(s) could be trampled by animals too. This call could also include a HART response given the risk posed.
Essentially it's a very basic call that has huge scope to work with but hey we have Devs that can't be bothered to make bespoke calls for the UK server they just C&P from the US server and their responses are totally different.