Alfred keeps escaping
I decided to let Cara out with the other cattle and leave Alfred free to roam around the yard. I was sure he couldn't get in with Cara.
How wrong was I! He discovered that he could get in under the lower rail, I watched him the second time and it was funny. He basically got his two front legs over and then dragged himself through with great difficulty.
All sorted now, some sheep wire nailed across kept him from getting out, but now also stops Harry & Stella getting into the top field from the yard.