If anything like the cattle here, there are a lot of calves out and very excitable at the mo. I have to go through a cattle field to hack out, but that's with a horse, which they dont see as a threat, just as something interesting, we still give them a VERY wide berth. And I would never contemplate taking my dog through there.
TBH I think when there are young calves and cows in a field it would be sensible for dog walkers to choose another route for a few weeks. Farmers have to make a living and young cattle are part of that, taking a dog through is just foolhardy IMO. Of course they have the 'right to' but then I have the 'right' to ride my horse on a massively busy A road - do I do it, no, because it's too dangerous. Here the danger is likely to lessen as the calves get older, tho not disappear, so common sense would say wait and go another route till that point.