Not knowing the area at all, I decided to run wherever looked good for 7 miles and then turn and retrace my steps. When I came to a cattle-grid across the road I didn't think much of it, but when a little later I came to a group of farm buildings and the end of the road I should probably have admitted defeat. Instead, I set off down a side lane signposted as a public footpath.
After a short distance, I realised I was chasing a herd of cows down the narrow lane away from the farm. I slowed to a walk. Fortunately they suddenly turned into a field for no apparent reason. It turned out there was a tape across the lane ahead which may or may not have been an electric fence. I counted my blessings and ducked under it to continue down the lane - hopefully back to some regular roads. It wasn't to be. Instead, it became clear that the lane was really a cattle thoroughfare between fields which went no further than another field over.
So I admitted my 7/7 run was not going to be that simple and turned around to head back. As I ducked under the electric tape again I saw this:
Again they turned to run away from me. This time I would be chasing them away from the field they probably wanted to be in and right into the farm. Suspecting this might displease the farmer, I decided to try to edge slowly past them.
Happily my youth in rural England left me unafraid of even a large number of these large animals (although still a little scared of farmers apparently) and I managed to edge by as they filed past me.
I decided to make my run a loop with a shorter out-and-back to adjust the total length which was better anyway and although gate-gate or cow-gate or whatever you'd like to call my dead-end run through a dairy farm slowed down the first half of my run, I managed to complete my 14 miles and do the second half at least at the pace I'd planned.