I wonder if the one resting in the foreground is the old 'tame' female 'Paula' who was one of the early animals in GD's animal collection. I don't think Jersey ever bred them , probably she was too humanised.
I'd say she is in the foreground- heavier/older looking. She was older than the male(or at least she'd been there a lot longer as a single animal.) I think the male may have been one born at Whipsnade.