What is poisonous to sheep?

Question

Was wondering what is poisonous to sheep and cattle?

I noticed that when they graze they eat pretty much anything.
So what types of plants would be poisonous to them?

Answer 1

It is a type of weed called sheep sorrel (Rumex acetosella). Although livestock needs to graze the weed in large amounts. Need time to flip through weeds literature to come up with better ones. If I'm too late I'll put the information in the comments box.

Edit: One more link for weeds poisonous to livestock. It is for Ontario and I know what you're thinking: Oh, but that is Ontario! Not a problem. The weeds of North America are so invasive that these weeds will be widespread enough.

Answer 2

red clover can be harmful to ewes that are pregnant causing them to abort their lambs.
for a more complete list check with your county agriculture extension office