Option A - Stop producing coveted assets -
Option B - Restrict access with Border control via a Fence - But you say that's impractical , which I can believe.
Option C- Grow more sacrificial plants and accept the losses for as long as you can.
Option D - Move to a different location
Option E - Protect with force and kill the Deer
I've heard about the ZooPoo thing but I think thats just a clever little ploy dreamed up by some dragons den wannabe to sell to a gullible public.
I appreciate this may look like an allegory - its not , just listing what I think are the options.
Option G - Get a pet wolf?