Mostly I was thinking of a 3D tile view - not isometric because when it comes to puzzles I think it can get confusing.

I hadn't considered the idea of adding other 'enemy' animals and I really think its a good idea. However I think 'tools' have to be added to stop/kill/cage the enemy animals.

Horses are good - also can be used by the farmer to move quickly from place to place.

reduction in points if some of the animals walks of a cliff, or gets nailed by nasty animals
This makes me think of a lemmings type scoring system. "You need to get 10 of the 15 cows from the Field to the Milking Shed in 3 minutes".

Thanks for the feedback