Haha no, all I know is -
1. There was a Flying Cow sign, which I photographed.
2. Someone else photographed the same sign and their picture was posted on a couple of blogs.
3. The Flying Cow sign was taken down and replaced with a 'Road Narrows' sign.
4. Another Flying Cow sign currently stands a few miles away. It is not the original Flying Cow sign which I photographed.
My guess is that someone doctored the first sign as a joke. The second sign might have been altered at the same time, 10 years ago or more, I don't know as I only spotted it last week. The style is similar.
I bet if @bugmum asked the Tarporley farmer's missis about it we'd hear that it was a stag night stunt or some local private joke or prank contest. Or, OR, there really are flying cows in Cheshire.
Have to mention that the sign amused me back in the day because Escet had been drawing nonsensical road signs for fun and one was 'Wingèd Cattle'.
(Note the grave accent. It's part of the rather obscure joke.)
Others I remember were 'Paradox Ahead' with the famous square/round pillars drawing and 'Pi (recurring)'.
So when I saw an actual 'Wingèd Cattle' sign I had to snap it to show to him. It was a coincidence as he was away at university and hadn't seen the road sign. He may have thought I'd altered the photo to pull his leg.
This might help to explain part of what has happened to the sign, and why it appears to have been shifted to one side!