Pokeweed

The pig surrounded by pokweed below is Charmaine (owned by Karen M), appearing bored with it all ... or maybe just gloriously happy ... Apparently pigs tend to avoid pokeweed (as Charmaine does) ... but it's perhaps worth taking a weed inventory of your pastures, just in case.

"Swine are most frequently poisoned by pokeweed. Symptoms include staggering, vomiting, posterior paralysis, tremors, and death. Post- mortem findings show swollen, dark liver and severe hemorrhagic gastritis" (Patterson 1929).

References:
Patterson, F. D. 1929. Pokeweed causes heavy losses in swine herd. Vet. Med. Small Anim. Clin., 24: 114.